INSTRUCTION MANUAL Precision Integrating Sound Level Meter with 1/3 octave band real-time analyzer NA-27 3-20-41 Higashimotomachi, Kokubunji, Tokyo 185-8533, Japan http://www.rion.co.
Organization of This Manual This manual describes the features, operation and other aspects of the Precision Integrating Sound Level Meter with 1/3 octave band real-time analyzer NA-27. If the unit is used together with other equipment to configure a measurement system, consult the documentation of all other components as well. The following pages contain important information about safety. Be sure to read and observe these in full. This manual contains the following sections.
Remote Control (NA-27RC1) Explains the names and functions of the operation buttons on the panel of the remote control. Technical Notes Provides information about the microphone, preamplifier, basic configuration of the sound level meter, and measurement functions. Error Messages Lists error message that can appear during startup, as well as suitable countermeasures. Optional Accessories Explains how to use the optional accessories available for the unit.
FOR SAFETY In this manual, important safety instructions are specially marked as shown below. To prevent the risk of death or injury to persons and severe damage to the unit or peripheral equipment, make sure that all instructions are fully understood and observed. Caution Important Disregarding instructions printed here incurs the risk of injury to persons and/or damage to peripheral equipment. Disregarding instructions printed here incurs the risk of damage to the product.
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Precautions z Operate the unit only as described in this manual. z The NA-27 is a precision instrument. Protect it from shocks and vibrations. Take special care not to touch the microphone diaphragm. The diaphragm is a very thin metal film which can easily be damaged. z Use only the microphone/preamplifier assembly with the number as shown on the name plate of the unit. z Ambient conditions for operation of the unit are as follows: temperature range -10 to +50ºC, relative humidity 30 to 90%.
Contents FOR SAFETY ...................................................................................................iii Outline ................................................................................................................ 1 Controls and Functions .................................................................................. 4 Carrying Case and Accessories ..................................................................... 4 Top View ...............................................
Takt-Max Sound Pressure Level Measurement (Ltm3, Ltm5) ....................... 54 Percentile Sound Pressure Level Measurement (Lx)................................... 57 1/1-Octave and 1/3-Octave Analysis ......................................................... 59 1/1-Octave and 1/3-Octave Analysis for Instantaneous Value (LA, LC, Lp) ............................................................................................ 59 1/1-Octave and 1/3-Octave Analysis for Maximum and Minimum Level (Lmax, Lmin) .
Microphone Extension Cable (EC-04 series) ........................................... 109 Amplifier Circuit Configuration ............................................................... 112 Frequency Weighting Network ................................................................. 113 RMS Detection Circuit ............................................................................. 114 Measurement Functions ............................................................................ 117 Noise Floor .....
Outline The precision integrating sound level meter NA-27 allows digital 1/1-octave and 1/3octave analysis in real time. It conforms to legal requirements for quantity measurements and to JIS and IEC standards. Using the output signal from a single microphone, the NA-27 can determine values for different time constants and frequency weighting settings simultaneously.
Outline Processing functions in main channel and sub channel *1 Lmax, Lmin, Leq, LE, Ltm3, Ltm5 are calculated simultaneously from Lp sampled at 10 ms intervals. *2 Lx values are calculated simultaneously from Lp sampled at 100 ms intervals for measurement times up to 1 h. For measurement times over 1 h, the sampling interval increases by 100 ms for every hour. *3 Set with the SETUP menu screen. *4 Set with the DISPLAY menu screen.
Outline Block diagram of NA-27 3
Controls and Functions Carrying Case and Accessories The unit is supplied with the parts listed below. Verify that all parts are complete and that there is no damage. If any parts are missing or damaged, please contact the supplier.
Controls and Functions 5
Controls and Functions Top View Microphone/preamplifier The microphone and preamplifier are configured as an integrated assembly. The microphone and preamplifier are labeled with a serial number which must match the number shown on the rear of the main unit. The microphone/preamplifier assembly can be removed from the sound level meter and connected via an optional extension cable, for measurements a distance. Display The backlit liquid crystal display has a resolution of 192 × 192 dots.
Controls and Functions Operation keys START/STOP key Press to start and to terminate the sound pressure level measurement (including the various processing functions). The key is also used to store data in memory. PAUSE/CONT key Serves to temporarily pause and resume the measurement. When the data exclusion (back-erasing) function is used, data for a certain number of seconds before the key was pressed can be excluded from processing.
Controls and Functions CAL key Pressing this key activates the built-in oscillator for electrical calibration of the NA-27 or for level matching of the NA-27 and connected equipment. FREQ WEIGHT key Selects the frequency weighting characteristic for the main channel. Available settings are "A" weighting (A), "C" weighting (C), and flat frequency response (FLAT). The frequency weighting characteristics for the sub channel are set with the SETUP menu screen.
Controls and Functions keys Serve to move the marker during frequency analysis. When a menu is displayed, the keys serve to select parameters. ENTER key When a menu is displayed, the key serves to accept a setting. PRINT key Serves to start and stop printout of the current measurement screen or of data stored in memory on a connected printer (DPU-414, CP-10, CP-11; option). SETUP key Pressing this key calls up the SETUP menu screen, for setting measurement parameters.
Controls and Functions Hand strap The strap should be used to safely carry the unit during field work.
Controls and Functions Power switch This sliding switch serves to turn the unit on and off. Contrast control Serves to adjust the display contrast. Use the supplied miniature screwdriver for the adjustment. Backlight key Pressing this key activates the display backlight. After about one minute, the backlight turns itself off automatically. EXT DC IN connector The optional AC adapter NC-94A can be connected here for powering the unit from an AC outlet.
Controls and Functions Rear View Battery compartment The unit uses four main batteries (IEC R14P) and one lithium battery (CR-1/3N) for memory backup. Guide hole This hole serves to fasten the supplied tripod adapter NA-27-S05. Name plate The model name and type, certification number, microphone number, preamplifier number, serial number, and manufacturing date are shown here.
Controls and Functions Bottom View Strap fastening screw The hand strap is to be fastened here. Using the supplied tripod adapter, the unit can also be mounted on a camera tripod. I/O connector Serves for input and output of control signals and measurement data. A printer or computer can be connected here.
Controls and Functions Measurement Screen The actual appearance of the measurement screen depends on the selected measurement parameters. A representative example is shown below. The illustration shown above may differ slightly from the actual screen display of the unit, regarding fonts, character size etc.
Controls and Functions 15
Preparations This section describes the steps which are necessary before starting a measurement. Be sure to set the power switch to OFF before inserting or removing batteries and connecting or disconnecting any cables. Backup Battery The backup battery (CR-1/3N, lithium) serves to maintain settings and data stored in memory also while the unit is turned off. In normal use, a backup battery should always be inserted. Proceed as described below. 1.
Preparations Important The life of the backup battery is about two years. To be on the safe side, you should replace the battery every 1 to 1-1/2 years. When the battery is removed, all stored data as well as the time and date settings are lost. If necessary, use the printer DPU-414, CP-10 or CP-11 to print out settings and data before changing the battery. After replacement, set the clock and date again, as described on page 24.
Preparations Power Supply The unit can be powered by four IEC R14P (size C) batteries (alkaline or manganese) or the optional AC adapter. The life of the batteries depends on various usage factors. Representative figures are shown below. Battery life (at room temperature, 1/3-octave analysis, continuous operation) Alkaline batteries: approx. 8 hours Manganese batteries: approx.
Preparations Important Take care not to reverse the (+) and (-) polarity when inserting a battery. Always use four identical batteries, and replace batteries only as a set. Mixing battery types or old and new batteries can lead to damage. Remove the batteries from the unit if it is not to be used for a week or longer. When the battery voltage drops near the operation limit of the unit, the indication LOW appears on the display.
Preparations For long continuous measurements, it is preferable to power the unit from the AC adapter. AC adapter connection To power the unit from the optional AC adapter (NC-94A), connect it as shown below. Important Do not use any other AC adapter except the optional NC-94A to prevent the possibility of overheating and damage. Caution While the AC adapter is in use, do not coil or bend the power cable. Do not cover the AC adapter or power cable with paper, cloth or the like.
Preparations Tripod (option) Mounting For long-term measurements, the unit can be mounted on the sound level meter tripod ST-80 (option). In this case, the supplied tripod adapter is required. Proceed carefully, to avoid dropping the unit or tipping over the tripod. Wind noise at the microphone can cause measurement errors. To prevent this, you should use the supplied windscreen WS-02 in cases where wind may be a problem. (For technical details, please refer to page 122.
Preparations Insert the stud of the tripod adapter into the guide hole on the rear of the unit, and fasten the adapter securely with the fastening screw. Microphone grid Important Never remove the microphone grid, because this can lead to damage. Before using the microphone and before putting it away, always check that the microphone grid has not become loose. If this has happened, refasten the microphone grid firmly and then use or store the microphone.
Preparations Trigger Input An external trigger signal can be used to initiate the measurement (see page 68). Use a logic-level signal or shorten the trigger connector. Using the Backlight Pressing the LIGHT key on the side of the unit turns the display backlight on, making it easier to read in dark locations. The backlight shuts itself off automatically after about a minute.
Preparations Setting the Date and Time The NA-27 incorporates a clock which allows recording the date and time along with measurement data. Note The clock will stop running if power is turned off and no backup battery is inserted. Set the date and time as described below. 1. Set the power switch on the side of the unit to ON. For an explanation of the display after power-on, please refer to page 43. 2. Press the I/O key. The I/O menu screen appears.
Preparations 3. Use the and keys to move the flashing cursor to the "DATE" item. The currently set date (such as 96/04/08) is shown in the bottom left corner of the screen. 4. Use the and keys to move the cursor to the year, month, and day field. Use the INC and DEC keys to set the numbers. Make the setting in the order year, month, day, using two digits for each field. Enter only the last two digits for the year. 5. When the setting is correct, press the ENTER key.
Preparations Calibration Before starting a measurement, the NA-27 must be calibrated. There are two types of calibration, namely electrical calibration and acoustic calibration using a pistonphone. When compensation for atmospheric pressure is not required, it suffices to perform electrical calibration only. Electrical calibration Calibration is carried out by setting the unit to the CAL mode. If the display reads 94.0 dB, calibration was completed successfully.
Preparations 5. Use the supplied miniature screwdriver to adjust the calibration control on the side of the unit so that the level reading is 94.0 dB. 6. Press the CAL key once more to return to the measurement screen. Note The calibration control is a multi-turn type. The value may not change on a single turn. If a measurement is currently in progress (indicated by the "measurement in progress" triangle or the "pause" mark), or if a menu screen is currently shown, calibration cannot be carried out.
Preparations Acoustic calibration with pistonphone For acoustic calibration, the Rion pistonphone NC-72 (option) is mounted to the microphone of the sound level meter, and adjustment is performed so that the reading of the meter is equal to the sound pressure level inside the coupler. Important Be very careful when inserting and removing the microphone to and from the coupler, to avoid a sudden pressure buildup which could destroy the membrane of the microphone. 1. Turn off the pistonphone. 2.
Preparations 7. Mount the 1/2-inch adapter on the coupler of the pistonphone. 8. Insert the microphone very carefully and slowly all the way into the coupler. 9. Set the power switch of the pistonphone to ON. 10. Adjust the calibration control on the side of the NA-27 with the supplied miniature screwdriver so that the level reading matches the calibration value indicated on the pistonphone.
Preparations Using the Menu Screens The NA-27 has four types of menu screens, namely SETUP, MEMORY, DISPLAY, and I/O. Basic operation principles are the same for all four screens. The following example explains how to use the SETUP menu screen to set the Leq measurement time to 10 minutes and the time constant for the sub channel to "SLOW". 1. Press the SETUP key. The SETUP menu screen appears. 2. Use the or key to move the cursor to the "Leq Time" item. 3.
Preparations 11. Press the ENTER key. The indication changes to "SLOW" and the cursor moves to the "Operation" item. The time constant of the sub channel is now set to "SLOW". 12. Press the SETUP key to return to the original screen. Menu screen conventions z z Pressing the same menu screen key again returns to the measurement screen. Pressing a different menu screen key allows switching to a different menu. Pressing the new menu screen key again returns to the measurement screen.
Preparations Menu Screens The contents of all menu screens are reproduced below. The left side always shows the setting item and the right side the parameter that can be changed. For more information on changing settings, please refer to the section about setting measurement parameters on page 36.
Preparations DISPLAY menu screen MAIN ADD DISP : OFF Lmax / Lmin SUB DISP ADD DISP PEAK DISP : OFF : OFF : OFF ON Lmax / Lmin ON Lx SELECT : : : : : : : : : : OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF ON ON ON ON ON ON ON ON ON ON PRINT MODE SUC.
Preparations Factory Default Settings The factory default settings for all menu screens are reproduced below. The left side shows the setting item and the right side the default parameter setting. SETUP menu screen MEASURE MODE Leq Time Lx Time BACK ERASE TIME Lmax / Lmin TYPE : : : : : LEQ 1S 10 S 0S AP TRIGGER MODE TRG LEVEL SLOPE TRG TIME PERIOD DELAY TIME Sub Frq.
Preparations DISPLAY menu screen MAIN ADD DISP : OFF SUB DISP ADD DISP PEAK DISP : OFF : OFF : OFF Lx SELECT : : : : : : : : : : OFF ON ON ON ON ON OFF OFF OFF OFF PRINT MODE SUC. PRINT BLK START END INTERFACE PORT : : : : : SINGLE AUTO 1 00001 00001 SERIAL BAUD RATE SERIAL OPTICAL PRINTER : 9600 : 115200 : 9600 BEEP : OFF L1 L5 L10 L50 L90 L95 L99 Lmax Lmin Leq I/O menu screen REMOTE CONTROL : OFF DC OUT DATE TIME VERSION : MAIN : YY / MM / DD : HH:MM : .
Setting Measurement Parameters Before carrying out a measurement or frequency analysis with this unit, the measurement parameters must be set up as described below. Menu screen settings SETUP menu screen MEASURE MODE: LEQ Lx Selects whether to measure power (Leq) or percentile values (Lx). Leq Time: 1 to 99 S 1 to 99 M 1 to 99 H Sets the measurement time for power measurements. Possible settings are 1 to 99 seconds in 1 second steps, 1 to 99 minutes in 1 minute steps, 1 to 99 hours in 1 hour steps.
Setting Measurement Parameters Explanation This example uses 10 frequency analysis results for instantaneous levels. Table 1 shows the values. The shaded data are the maximum levels for each frequency band. The framed column shows the frequency band data at the point when the all-pass level was maximum. In BAND max. mode, the shaded data will be held. In AP max. mode, the framed data will be held. Fig. 1 shows a comparison of the results.
Setting Measurement Parameters TRIGGER MODE: OFF LEVEL EXTRN TIME Sets the trigger mode for starting the measurement. (See pages 68 to 73.) OFF: Trigger mode is disabled. LEVEL: Trigger level can be set from 10 to 140 dB in 1 dB steps. SLOPE: - or + are used to set the slope for level triggering. EXTRN: Selects a CMOS logic-level signal to be used as trigger, supplied to the trigger input on the side of the unit. TRG TIME: Can be set from 00 h 00 m to 23 h 59 m in 1 minute steps.
Setting Measurement Parameters MEMORY menu screen MEMORY BLOCK: AUTO1 AUTO2 MANU Selects the memory block for storing or recalling data. BLOCK CLEAR: OFF EXEC Serves to erase stored data. AUTO STORE TYPE: SINGLE GROUP Determines whether auto store data are composed of a single processing function or of all processing functions. PERIOD: 1 to 10 ms, 10 to 990 ms Determines the store interval for auto store. Can be set from 1 to 10 milliseconds in 1 ms steps and from 10 to 990 milliseconds in 10 ms steps.
Setting Measurement Parameters Directory UP 96 / 05 / 02 96 / 05 / 04 96 / 05 / 10 96 / 05 / 10 96 / 05 / 12 96 / 05 / 3 DOWN z [ AU 1: 1 / 1 12:34:56 ] [ AU 2: 1 / 3 11:22:33 ] [ 001: 1 / 3 10:10:10 ] [ 002: SPL 15:15:15 ] [ 003: SPL 17:17:15 ] [ 004: SPL 19:19:15 ] : : [ 200: SPL 96 / 05 / 25 15:15:15 ] Indicates the type and store date and time of data in the mass memory. The date/time is indicated as follows. AU1, AU2: Auto store start date/time/The date/time is indicated as follows.
Setting Measurement Parameters I/O menu screen PRINT MODE: SINGLE SUCCESSIVE Determines whether the printer (DPU-414, CP-10, CP-11) prints only one sheet or operates continuously. The "SUCCESSIVE" setting is valid only in recall mode. SUC. PRINT BLK: AUTO1 AUTO2 MANU Specifies the memory block for successive printing. START: 00001 to END: 00001 to Specifies the start address and end address of the memory block specified for printing.
Sound Pressure Level Measurement The NA-27 offers various kinds of measurements: instantaneous value (Lp, Lmax, Lmin, Lpeak), power (Leq, LE, Ltm3, Ltm5), and percentile value (Lx). The maximum sound pressure level (Lmax), minimum sound pressure level (Lmin), and waveform peak hold (Lpeak) refer to the instantaneous level within the measurement time. Except for the instantaneous level (Lp), the measurement applies to the preset measurement time.
Sound Pressure Level Measurement If the date and time are not set, the indication "RTC Read Error!!" appears after turning on the power. In this case, use the I/O menu screen to set the date and time, as described on page 24. Instantaneous Sound Pressure Level Measurement (LA, LC, Lp) To perform a measurement, carry out the following steps. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.
Sound Pressure Level Measurement 4. Use the TIME CONST key to select the desired time constant setting. Normally, the "FAST" setting should be used. 5. Use the LEVEL UP/DOWN keys to select the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear (the bar graph should register to about the middle of the range). 6. The level reading shown on the display corresponds to the current noise level (sound pressure level). The reading is updated once every second.
Sound Pressure Level Measurement 3. Use the and keys to set the parameter to ON. 4. Press the ENTER key. The "SUB DISP" item is now set to ON. The cursor moves to the "ADD DISP" item. 5. Press the DISPLAY key to return to the measurement screen. The display appearance changes as shown below. If frequency weighting and time constant for the sub channel are set to the same values as for the main channel, the sub channel display does appear, even if set to ON.
Sound Pressure Level Measurement Maximum and Minimum Sound Pressure Level Measurement (Lmax, Lmin) The maximum and minimum sound pressure level for a given measurement interval can be measured. To make the measurement, carry out the following steps. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.) 2. Press the SETUP key to call up the SETUP menu screen.
Sound Pressure Level Measurement 9. Use the TIME CONST key to select the desired time constant setting. Normally, the "FAST" setting should be used. 10. Use the LEVEL UP/DOWN keys to select the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear (the bar graph should register to about the middle of the range). 11. Press the START/STOP key. The LED indicator and the mark on the display start to flash, and the maximum and minimum sound pressure level measurement begins.
Sound Pressure Level Measurement Waveform Peak Hold Measurement (Lpeak) The waveform peak sound pressure level for a given measurement interval can be measured. This measurement is carried out in the sub channel. To make the measurement, carry out the following steps. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.) 2. Press the SETUP key to call up the SETUP menu screen.
Sound Pressure Level Measurement 8. Press the DISPLAY key to bring up the DISPLAY menu screen. 9. 10. 11. 12. 13. Set "SUB DISP" to ON. Set "PEAK DISP" to ON. Press the DISPLAY key to return to the measurement screen. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. Use the LEVEL UP/DOWN keys to select the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear (the bar graph should register to about the middle of the range).
Sound Pressure Level Measurement 14. Press the START/STOP key. The LED indicator and the mark on the display start to flash, and the waveform peak hold measurement begins. When the measurement time set in step 4 has elapsed, the measurement stops automatically. When wishing to terminate the measurement earlier, press the START/ STOP key. If an overload condition has occurred at least once during the measurement, the "OVER" indication is shown on the display.
Sound Pressure Level Measurement Equivalent Continuous Sound Pressure Level Measurement (Leq) To make the equivalent continuous sound pressure level measurement, carry out the following steps. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.) 2. Press the SETUP key to call up the SETUP menu screen. (For an explanation of how to use the SETUP menu screen, refer to page 30.) 3.
Sound Pressure Level Measurement 10. Use the LEVEL UP/DOWN keys to select the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear (the bar graph should register to about the middle of the range). 11. Press the START/STOP key. The LED indicator and the mark on the display start to flash, and the equivalent continuous sound pressure level measurement begins. When the measurement time set in step 4 has elapsed, the measurement stops automatically.
Sound Pressure Level Measurement Sound Exposure Level Measurement (LAE) To make the sound exposure level measurement, carry out the following steps. The procedure is almost identical to the equivalent continuous sound pressure level measurement. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.) 2. Press the SETUP key to call up the SETUP menu screen.
Sound Pressure Level Measurement When the measurement time set in step 4 has elapsed, the measurement stops automatically. When wishing to terminate the measurement earlier, press the START/ STOP key. If an overload condition has occurred at least once during the measurement, the "OVER" indication is shown on the display. The display reading corresponds to the noise level (sound pressure level). Using the PAUSE/CONT key, you can pause and resume the level reading and bar graph display. 12.
Sound Pressure Level Measurement 6. Press the DISPLAY key to bring up the DISPLAY menu screen. 7. Set "SUB DISP" to ON and set "ADD DISP" to "Ltm3/Ltm5". 8. Press the SETUP key to call up the SETUP menu screen. 9. Set "SUB FRQ. WEIGHT" to "A" weighting and set "SUB TIME CONST" to FAST. 10. Press the SETUP key to return to the original screen.
Sound Pressure Level Measurement 11. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 12. Use the LEVEL UP/DOWN keys to select the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear (the bar graph should register to about the middle of the range). 13. Press the START/STOP key. The LED indicator and the mark on the display start to flash, and the takt-max sound pressure level measurement begins.
Sound Pressure Level Measurement Percentile Sound Pressure Level Measurement (Lx) To make the percentile sound pressure level measurement, carry out the following steps. The procedure is almost identical to the equivalent continuous sound pressure level measurement. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. (For an explanation of the power-on procedure, refer to page 42.) 2. Press the SETUP key to call up the SETUP menu screen.
Sound Pressure Level Measurement 7. Select up to five Lx settings out of L1 to Leq. If five settings are already selected and you wish to use other settings, turn unused settings OFF first. 8. Press the DISPLAY key to return to the original screen. 9. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. The selected five percentile levels are shown. 10. Use the FREQ WEIGHT key to set frequency weighting to "A". 11.
1/1-Octave and 1/3-Octave Analysis Note If measurement settings such as level range or frequency weighting were changed during pause in instantaneous value mode, the new settings will apply immediately when pause is released. If measurement settings such as level range or frequency weighting were changed after processing, the new settings will be effective only when processing the next measurement.
1/1-Octave and 1/3-Octave Analysis 1/1-Octave and 1/3-Octave Analysis for Maximum and Minimum Level (Lmax, Lmin) To make the measurement, carry out the following steps. The procedure is almost identical to the instantaneous value measurement. 1. Set the power switch on the side of the unit to ON. Call up the DISPLAY menu screen by pressing the DISPLAY key, make the necessary settings, and press the DISPLAY key again to close the menu. 2.
1/1-Octave and 1/3-Octave Analysis 1/1-Octave and 1/3-Octave Analysis for Equivalent Continuous Sound Pressure Level (Leq) To make the measurement, carry out the following steps. The procedure is almost identical to the instantaneous value measurement. 1. Set the power switch on the side of the unit to ON. Call up the DISPLAY menu screen by pressing the DISPLAY key and make the necessary settings. 2. Press the SETUP key to call up the SETUP menu screen and make the necessary settings. 3.
1/1-Octave and 1/3-Octave Analysis 1/1-Octave and 1/3-Octave Analysis for Percentile Sound Pressure Level (Lx) To make the measurement, carry out the following steps. The procedure is almost identical to the instantaneous value measurement. 1. Set the power switch on the side of the unit to ON. Call up the DISPLAY menu screen by pressing the DISPLAY key and make the necessary settings. 2. Press the SETUP key to call up the SETUP menu screen and make the necessary settings. 3.
1/1-Octave and 1/3-Octave Analysis Explanation of Analysis Screens 1/1-octave analysis The staircase shape on the display represents the 1/1-octave analysis result. From left, the bars correspond to 16, 31.5, 63, 125, 250, 500, 1 k, 2 k, 4 k, 8 kHz. To read the levels at these frequencies, use the and keys to move the marker to the desired point. The frequency and level are then shown on the right of the screen under the indication "MARK".
1/1-Octave and 1/3-Octave Analysis 1/3-octave analysis The staircase shape on the display represents the 1/3-octave analysis result. From left, the bars correspond to 12.5, 16, 20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1 k, 1.25 k, 1.6 k, 2 k, 2.5 k, 3.15 k, 4 k, 5 k, 6.3 k, 8 k, 10 k, 12.5 kHz. To read the levels at these frequencies, use the and keys to move the marker to the desired point.
1/1-Octave and 1/3-Octave Analysis Numeric display Because it will be difficult to read all numeric values from the 1/1-octave and 1/3-octave screen, the numeric display function should be used for this purpose. Use the GRP/NUM/ L-T key to toggle between the graphical and numeric display. The numeric readings are shown in list format with the frequency on the left and the level on the right.
Data Exclusion (Back-Erase) Function When a measurement is being carried out and data are being processed, the PAUSE/ CONT key can be used to suspend the measurement. Normally, data up to the point at which the PAUSE/CONT key was pressed will be included in processing, but the data exclusion function makes it possible to exclude (back erase) data from an interval of 1 to 5 seconds before the key was pressed. To activate the back-erase function, carry out the following steps. 1.
Data Exclusion (Back-Erase) Function When the PAUSE/CONT key is pressed during measurement, the pause mark appears, the indication "BE" is shown on the top right of the display for about a second, and the data are back-erased. The measurement time is also reduced by the number of seconds set for the back-erase function. If the back-erase interval is longer than the measurement time, the measurement time becomes "0".
Trigger Function The NA-27 incorporates three kinds of trigger functions: level trigger, external trigger, and time trigger. The trigger can also be disabled completely. Trigger mode selection 1. Press the SETUP key to call up the SETUP menu screen. (For an explanation of how to use the SETUP menu screen, refer to page 30.) 2. Set the "TRIGGER MODE" item as desired. There are four possible settings, as listed below. OFF: Trigger function is disabled.
Trigger Function When the trigger function is enabled, the indication "TRG" appears in the top left of the display. When the START/STOP key or the STORE key is pressed, the indication "TRG" is shown in reverse, and the unit goes into standby mode until the trigger condition is fulfilled. When the trigger condition is fulfilled, the "TRG" indication goes from reverse to normal, and measurement starts.
Trigger Function Level trigger Level setting range: Slope: 10 to 140 dB in 1 dB steps +/- 1. Set the trigger level. 2. Set the slope. When set to (+), the measurement starts when the input signal exceeds the trigger level. When set to (-), the measurement starts when the input signal, after having risen once above the trigger level, falls below the trigger level for the first time.
Trigger Function External trigger The external trigger can either be a CMOS logic-level signal supplied to the trigger input or it can be activated by shortening the trigger input terminals. A. Using a CMOS logic-level signal 1. Set the power switch on the side of the unit to OFF and connect the trigger cable. 2. When the connection has been established, set the power switch to ON and use the SETUP menu screen to select the setting "EXTRN" for the trigger function.
Trigger Function B. Shorting the trigger input 1. Set the power switch on the side of the unit to OFF and connect the trigger cable. 2. When the connection has been established, set the power switch to ON and use the SETUP menu screen to select the setting "EXTRN" for the trigger function. 3. Use a 2.5 mm miniature phone plug and shielded cable, and configure the trigger circuit as shown above. 4. When the relay contacts close, the trigger is activated and measurement starts.
Trigger Function Time trigger TIME TRG (Measurement start time): PERIOD (Measurement repeat interval): 00 h 00 m to 23 h 59 m in 1 minute steps 0 h to 24 h in 1 hour steps 1. Set the measurement start time with the "TIME TRG" item. 2. Set the measurement repeat interval with the "PERIOD" item. z z When PERIOD is set to "0 H", the measurement is performed only once at the preset time.
Delayed Measurement The delayed measurement function allows the user to complete all preparations and perform the steps for measurement start, while having the actual measurement start only after a preset delay time. 1. Press the SETUP key to call up the SETUP menu screen. (For an explanation of how to use the SETUP menu screen, refer to page 30.) 2. Set the "DELAY TIME" item as desired. The setting range is 0 to 10 seconds, in 1 second steps.
Delayed Measurement If the trigger function is used concurrently, the delay time starts at the trigger point.
Memory Functions The NA-27 incorporates a memory that allows manual and automatic storing of measurement data ("mass memory") and a separate memory for measurement parameter settings ("condition memory"). Stored measurement results can be displayed by pressing the RECALL key. To protect stored data, the mass memory can be set to read-only. To use the memory, the backup battery must be inserted (see page 16).
Memory Functions Group store 200 data Store interval: measurement time interval The memory upper limit can be set with the "NUM" item on the MEMORY menu screen, as described on page 39.
Memory Functions Manual (Sound Pressure Level Mode) Storing data in memory At the point where the STORE key is pressed, the current instantaneous value and the various processing results are stored in memory. The procedure is as described below. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. (For an explanation of how to use the MEMORY menu screen, refer to page 30.) 3.
Memory Functions 6. Press the DISPLAY key to call up the DISPLAY menu screen. 7. Set "MAIN ADD DISP" and other items to the desired settings. 8. Press the DISPLAY key to return to the original measurement screen. 9. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 10. Use the INC and DEC keys to select the memory address in which to store the measurement data. 11. Press the START/STOP key to start the measurement.
Memory Functions Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the INC and DEC keys to select the memory address from which you want to display data. 3. Use the OPE MODE key to select the processing type for display (LC, Lmax etc.) The date/time shown on the display is the processing start date/time. To check the date/time when the STORE key was pressed, use the "Directory" item on the MEMORY menu screen.
Memory Functions Auto (Sound Pressure Level Mode) Single Store Storing data in memory 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. (For an explanation of how to use the MEMORY menu screen, refer to page 32.) 3. Set the "MEMORY BLOCK" item to "AUTO1" or "AUTO2 ". 4. Set the "AUTO STORE TYPE" to "SINGLE". 5. Press the SETUP key to call up the SETUP menu screen. 6.
Memory Functions 7. Press the DISPLAY key to call up the DISPLAY menu screen. 8. Set "MAIN ADD DISP" and other items to the desired settings. 9. Press the DISPLAY key to return to the original measurement screen. 10. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 11. Use the OPE MODE key, FREQ WEIGHT key, TIME CONST key, and LEVEL UP/DOWN keys to set the measurement parameters. 12. Press the STORE key to start the measurement.
Memory Functions Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the INC and DEC keys to select the memory address from which you want to display data. The date/time is indicated as follows. Instantaneous values: Date/time when instantaneous value was stored. Processed values: Date/time when processing was started.
Memory Functions Auto (Sound Pressure Level Mode) Group Store Storing data in memory The procedure for storing data in memory is described below. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. 3. Set the "MEMORY BLOCK" item to "AUTO1" or "AUTO2". 4. Set the "AUTO STORE TYPE" to "GROUP". 5. Press the SETUP key to call up the SETUP menu screen. 6.
Memory Functions 7. Press the DISPLAY key to call up the DISPLAY menu screen. 8. Set "MAIN ADD DISP" and other items to the desired settings. 9. Press the DISPLAY key to return to the original measurement screen. 10. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 11. Use the OPE MODE key, FREQ WEIGHT key, TIME CONST key, and LEVEL UP/DOWN keys to set the measurement parameters. 12. Press the STORE key to start the measurement.
Memory Functions Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the INC and DEC keys to select the memory address from which you want to display data. 3. Use the OPE MODE key to select the processing type for display (LC, Lmax etc.) The date/time shown on the display is the processing start date/time.
Memory Functions Manual (Frequency Analysis Mode) Storing data in memory At the point where the STORE key is pressed, the current instantaneous value and the various processing results are stored in memory. The procedure is as described below. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. 3. Set the "MEMORY BLOCK" item to "MANU". 4. Press the SETUP key to call up the SETUP menu screen. 5.
Memory Functions Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the INC and DEC keys to select the memory address from which you want to display data. 3. Use the OPE MODE key to select the processing type for display (LC, Lmax etc.). An example for recalled 1/3-octave analysis data is shown below. The date/time shown on the display is the processing start date/time.
Memory Functions Auto (Frequency Analysis Mode) Single Store Storing data in memory The procedure for storing data in memory is described below. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. 3. Set the "MEMORY BLOCK" item to "AUTO1" or "AUTO2". 4. Set the "AUTO STORE TYPE" to "SINGLE". 5. Press the SETUP key to call up the SETUP menu screen. 6.
Memory Functions 7. Press the DISPLAY key to call up the DISPLAY menu screen. 8. Set "MAIN ADD DISP" and other items to the desired settings. 9. Press the DISPLAY key to return to the original measurement screen. 10. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 11. Use the OPE MODE key, FREQ WEIGHT key, TIME CONST key, and LEVEL UP/DOWN keys to set the measurement parameters. 12. Press the STORE key to start the measurement.
Memory Functions Pressing the STORE key again causes the process to be repeated from step 12. * Upper limit can be set with MEMORY menu screen. Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the GRP/NUM/L-T key to select the type of display. The graphical display contains the following information. The date/time is indicated as follows. Instantaneous values: Date/time when instantaneous value was stored.
Memory Functions 2. When moving the cursor with the at the right of the screen changes. and keys, the frequency and level displayed The level-time display contains the following information. 1. Use the INC and DEC keys to select the memory address from which you want to display data. 2. Use the LEVEL UP/DOWN ( LT / LT ) keys to select the display compression ratio. Pressing the LT key widens the address range, and pressing the LT key narrows it down. 3. Use the and keys to select the frequency band.
Memory Functions Auto (Frequency Analysis Mode) Group Store Storing data in memory The procedure for storing data in memory is described below. 1. Set the power switch on the side of the unit to ON and wait until the measurement screen appears. 2. Press the MEMORY key to call up the MEMORY menu screen. (For an explanation of how to use the MEMORY menu screen, refer to page 32.) 3. Set the "MEMORY BLOCK" item to "AUTO1" or "AUTO2". 4. Set the "AUTO STORE TYPE" to "GROUP". 5.
Memory Functions 7. Press the DISPLAY key to call up the DISPLAY menu screen. 8. Set "MAIN ADD DISP" and other items to the desired settings. 9. Press the DISPLAY key to return to the original measurement screen. 10. Use the SLM / 1/1 / 1/3 key to activate the sound pressure level measurement screen. 11. Use the OPE MODE key, FREQ WEIGHT key, TIME CONST key, and LEVEL UP/DOWN keys to set the measurement parameters. 12. Press the STORE key to start the measurement.
Memory Functions Pressing the STORE key again causes the process to be repeated from step 12. * Upper limit can be set with MEMORY menu screen. Reading from memory The procedure for reading data from memory is described below. 1. Press the RECALL key. 2. Use the GRP/NUM/L-T key to select the type of display. The graphical display contains the following information. The date/time shown on the display is the processing start date/time.
Memory Functions 1. Use the INC and DEC keys to select the memory address from which you want to display data. 2. Use the OPE MODE key to select the processing type for display (LC, Lmax etc.). 3. When moving the cursor with the and keys, the frequency and level displayed at the right of the screen changes. The level-time display contains the following information. 1. Use the INC and DEC keys to select the memory address from which you want to display data. 2.
Memory Functions An example for 1/1 and 1/5 compression is shown below. 3. Use the and keys to select the frequency band. 4. Use the OPE MODE key to select the type of processing.
Memory Functions Erasing Data All data stored in an address block can be erased as follows. Take care not to accidentally erase data that you want to keep. 1. Press the MEMORY key to call up the MEMORY menu screen. 2. Select the memory block which you want to erase. 3. Set the "PROTECT" item for the memory block to OFF. 4. Move the cursor to the "BLOCK CLEAR" item. 5. Use the and keys to select EXEC. 6. Press the ENTER key to erase all data in the selected memory block.
Memory Functions Recall Processing Using the recall processing function, power average (P_AVE), power sum (P_SUM), and reverb time (REVERB) can be calculated. The following explanation is for power average (P_AVE), but the procedure for other functions is identical. 1. Store data using the auto store function for frequency analysis in single (p. 89) or group (p. 93) mode. 2. Press the MEMORY key to call up the MEMORY menu screen. 3. Move the cursor to the "RECALL CALC" item. 4. Set the item to "P_AVE". 5.
Memory Functions 6. Use the INC and DEC keys to select the processing start address. (The left border of the screen corresponds to the processing start address.) 7. Use the and keys to select the processing end address. 8. The bottom of the screen shows "P_AVE . dB" (when power sum is selected: "P_SUM . dB"). The result for power average or power sum processing (for all frequency bands together) is shown on the graphical screen or the numeric list display.
Remote Control (NA-27RC1) The supplied infrared remote control (NA-27RC1) allows operating the sound level meter from a distance of up to 3 meters. The top panel of the control has buttons for controlling measurement progress and changing measurement parameter settings. START STOP key Serves to start and stop the measurement. PAUSE CONT key Serves to pause the measurement.
Remote Control To use the remote control, insert two IEC R03 (size AAA) batteries in the battery compartment on the rear. 1. Push the cover of the battery compartment down in direction of the arrow mark and slide it off. 2. Insert two IEC R03 (size AAA) batteries, taking care to establish correct polarity. 3. Replace the cover of the battery compartment. Important Take care not to reverse the (+) and (-) polarity when inserting a battery.
Technical Notes Microphone Measurements of sound pressure level can be carried out with a variety of microphone types. The precision integral sound pressure level meter NA-27 employs the prepolarized condenser microphone UC-53A that is compact and delivers stable and reliable response. Construction and Operation Principle As shown in the drawing below, a prepolarized condenser microphone consists of four main parts: diaphragm, backplate, insulator, and housing.
Technical Notes Frequency Response The frequency response of a sound field microphone is expressed as the frequency response in the reference direction of incidence (0º). The diagram below shows an example for the frequency response of the microphone UC-53A.
Technical Notes Directional characteristics The directional characteristics of a microphone is a measure of its differing sensitivity for sound waves arriving from various angles. Since the prepolarized condenser microphone used in the NA-27 is a pressure-sensitive type, it should be equally sensitive in all directions. However, refraction and cavity effects cause a certain microphone directional characteristics at high frequencies.
Technical Notes Thermal Characteristics The thermal characteristics of a microphone indicate how sensitivity changes at various temperatures. This is influenced by the choice of materials and the design of the microphone. Normally, materials with a linear expansion coefficient are used. The diagrams below show the thermal characteristics of the microphone UC-53A. Humidity Characteristics The humidity characteristics of a microphone indicate how sensitivity changes at various humidity levels.
Technical Notes Microphone (UC-53A) Specifications Nominal diameter: 1/2 inch Sensitivity: -28 dB (0 dB = 1 V/Pa at 1000 Hz) Frequency response: 10 to 20000 Hz Capacitance: 12 pF Diaphragm type: Titan alloy film Temperature coefficient: +0.005 dB/ºC (at 250 Hz) Humidity-dependent sensitivity change: 0.1 dB or less (at 250 Hz, RH below 95%, no condensation) Dimensions: 13.2 dia. × 12.
Technical Notes Preamplifier Preamplifier Requirement Since the condenser microphone is a small-capacity transducer, it has high impedance, especially at low frequencies. Therefore a very high load resistance is required to ensure uniform response extending to the low frequency range. The relationship between the microphone capacitance and the low-range cutoff frequency can be expressed as follows.
Technical Notes Microphone Extension Cable (EC-04 series) To reduce measurement deviations due to refraction effects and the acoustic influence of the operator, the microphone/preamplifier assembly can be detached from the main unit and connected via an extension cable. Optional cables are listed in the table below. 1. Set the power switch to OFF. 2. Loosen the preamplifier fastening screw and separate the microphone/preamplifier assembly from the main unit. 3.
Technical Notes 4. When mounting the microphone/preamplifier on a tripod, first fasten the microphone holder (supplied with the extension cable) to the tripod. Then insert the extension cable connector into the microphone holder.
Technical Notes When the output of the microphone/preamplifier is routed through an extension cable, certain limitations regarding measurable sound pressure level and frequency range will apply. This is due to the influence of the cable capacitance. The longer the cable, the lower the measurable sound pressure level and the lower the frequency limit. The diagram below shows the relationship between cable length, measurable sound pressure level, and frequency.
Technical Notes Amplifier Circuit Configuration The amplifier circuit configuration and level diagram of the NA-27 are shown below. The degree of attenuation and degree of amplification depends on the level range setting.
Technical Notes Frequency Weighting Network The NA-27 provides a choice between "A", "C" and "Flat" frequency weighting. The electrical characteristics of the weighting circuitry are as shown below. The volume impression (loudness) of a sound depends not only on the sound pressure level, but also on the frequency. At high or low frequencies, a sound is felt to be less loud than a sound of equal level in the midrange.
Technical Notes RMS Detection Circuit The sound pressure level meter uses rms detection. The effective value E (rms) is defined by the following equation. The voltage e which changes over time is raised to the power of 2, and integration for the time interval T is performed. The result is divided by T and the square root is extracted. The circuit configuration for performing the above mathematical operation looks as follows. The NA-27 performs all above processing functions in the digital domain.
Technical Notes The "Slow" time weighting setting is suitable for measuring the average of noise with fairly constant levels. Aircraft noise and high-speed train noise is usually transient noise with high fluctuation, but here the "Slow" setting is used to determine the maximum level for each noise event. The "10 ms" setting of the NA-27 results in a very short time weighting, enabling the meter to closely follow noise fluctuations.
Technical Notes Time weightings and time constant The time weighting circuit of the sound pressure level meter performs index averaging on the square of the sound pressure signal. The equivalent circuit is shown at right. τ is the time weighting, which equals CR. J The response of the index averaging circuit to a single burst signal is shown below.
Technical Notes Measurement Functions L Aeq (equivalent sound pressure level) For a sound pressure level signal that changes over time, the LAeq (equivalent sound pressure level) is a hypothetical constant sound pressure level that has the same energy as the actually measured signal in the measurement interval. It is determined by the following equation.
Technical Notes L AE (sound exposure level) The LAE (sound exposure level) is a hypothetical constant 1-second sound pressure level having the same energy as a single-event sound pressure level measured with A weighting. It is determined by the following equation.
Technical Notes second), and Lx processing is carried out every interval. The Lx reading can therefore be displayed already during measurement. L max , L min (maximum and minimum sound pressure level) Lmax is the maximum sound pressure level and Lmin the minimum sound pressure level encountered during a measurement. In the NA-27, the sampling interval for A/D conversion is 10 ms (100 samples per second), and the Lmax and Lmin values since the start of the measurement are stored.
Technical Notes Noise Floor The diagrams below show the residual noise of the NA-27, in the frequency weighting "A", "C" and "Flat" positions. The measurement was made with a 1/3 octave filter and a frequency analyzer.
Technical Notes Background Noise When measuring a certain sound in a certain location, all other sounds present at that location except the measurement target sound are background noise (also called ambient noise or dark noise). Since the sound pressure level meter will display the combination of target sound and background noise, the amount of background noise must be taken into consideration when determining the level of the target sound.
Technical Notes Windscreen (WS-02) During outdoor measurements or measurement of ventilation devices, wind noise can falsify measurement results. To counter such problems, the supplied windscreen WS-02 should be mounted on the microphone. The characteristics of the WS-02 are shown below. The attenuation of wind noise produced by the windscreen is about 25 dB for sound pressure level (A weighting) and 15 dB for sound pressure level.
Technical Notes 123
Technical Notes 124
Technical Notes I/O Connector The I/O connector on the NA-27 serves for input of control signals and input/output of data. It has the following functions.
Technical Notes 1/1-Octave Filter Characteristics The characteristics of the 1/1-octave filter in the NA-27 correspond to the JIS C 15131983 Type II, ANSI S1.11 Type 1D, and IEC 1260 1995 Class 1 specifications. The graph below shows the allowable attenuation tolerance according to JIS and the actual characteristics of the 1/1-octave filter in the NA-27.
Technical Notes 1/3-Octave Filter Characteristics The characteristics of the 1/3-octave filter in the NA-27 correspond to the JIS C 15131983 Type III, ANSI S1.11 Type 1D, and IEC 1260 1995 Class 1 specifications. The graph below shows the allowable attenuation tolerance according to JIS and the actual characteristics of the 1/3-octave filter in the NA-27. Important The frequency range of the NA-27 is 20 Hz to 12500 Hz.
Error Messages Error messages are shown when the unit is turned on. Messages 1 through 6 disappear after 3 seconds or when any key is pressed.
Error Messages 129
Optional Accessories Microphone Extension Cables (EC-04 series) To reduce measurement deviations due to refraction effects and the acoustic influence of the operator, the microphone can be detached from the unit and connected via an extension cable. Optional cables are listed in the table below.
Optional Accessories Level Recorder (LR-04, LR-06) Connection of a sound level recorder By connecting a level recorder to the NA-27, the sound pressure level changes over time can be recorded. Connect the AC output on the side of the NA-27 to the level recorder, as shown above. Recording procedure The steps for recording the sound pressure level on a level recorder are shown below.
Optional Accessories 4. Press the CAL key once more to return the NA-27 to the measurement mode. 5. Use the FREQ WEIGHT key of the NA-27 to set the frequency weighting characteristics. The time constant should be set at the level recorder. 6. Use the LEVEL UP/DOWN keys to set the level range. Choose a setting in which the "OVER" and "UNDER" indications do not appear.
Optional Accessories To record measurement results from the sub channel also, the optional splitter adapter CC-59 is required. Use to two level recorders and connect them as shown below.
Optional Accessories Using a Printer (DPU-414, CP-10, CP-11) Data gained during measurement and data stored in the memory of the NA-27 can be printed out on a printer. You can also produce hard copy of the menu screens. Connect the I/O interface on the bottom of the NA-27 to the printer (DPU-414, CP-10, CP-11), using a serial printer cable. The printer and cable are optional. 1. Set the power switches of the sound level meter and the printer to OFF. 2.
Optional Accessories Set the DIP switches of the printer as follows. Important The switch marked with an asterisk (switch 6 of DIP switch bank 2) serves for setting the data transfer speed. The ON position means 4800 bps and the OFF position 9600 bps. This setting must match the setting of the NA-27 (see description of I/O menu screen on page 35). Switches 7 and 8 of DIP switch bank 2 of printer CP-11 are set at the factory and should not be changed. Otherwise, correct printing may not be possible.
Optional Accessories Setting the software DIP switches of the DPU-414 Turn on the power while holding down the ON LINE key of the DPU-414. A printout showing the current status of the printer is produced. For details, please refer to the documentation of the DPU-414.
Optional Accessories Printing measurement parameters 1. Press the key for the desired menu (SETUP, MEMORY, DISPLAY, I/O). 2. Press the PRINT key to print out the current screen. Printing the screen during measurement Pressing the PRINT key causes a hard copy of the current screen (measured level, frequency weighting, time constant, overload conditions etc.) to be printed out. During store, the indication "AUTO STORE Now!!" is shown on the display for several seconds.
Optional Accessories Printing when I/O menu is set to SINGLE When the PRINT key is pressed, the current display is printed. Printing when I/O menu is set to SUCCESSIVE A. In sound level meter mode When the PRINT key is pressed, stored numeric data and corresponding addresses are printed, as shown in the example on the right. B. In frequency analysis mode When the PRINT key is pressed, frequency analysis data are printed successively, from the start address to the end address.
Optional Accessories Printing in recall mode In normal operation (current) mode, printing is always carried out as in SINGLE mode. An example for successive printout of data gathered with group store in a Leq processing mode is shown below.
Specifications Applicable standards General measurements, precision sound level meters IEC 61672-1:2002 Class 1, IEC 61260:1995 Class1 ANSI S1.11 Type1D, JIS C 1509-1:2005 Class1, JIS C 1514:2002 Class1, JIS C 1513:2002 Class1 IEC 60651 and IEC 60804 was withdrawn and replaced by IEC 61672-1. JIS C 1505 was withdrawn and replaced by JIS C 1509-1.
Specifications Reference range 50 to 110 dB (Sound level meter mode), 40 to 110 dB (frequency analysis mode) Max. measurement level 140 dB rms, 133 dB at c.f. 3, 143 dB peak for peak hold Noise Floor Typical 17 dB (A) rms, max. 20 dB (A) rms A weighting: Less than 20 dB C weighting: Less than 25 dB Flat: Less than 30 dB Frequency range 20 to 12500 Hz (including microphone) 10 to 20000 Hz (amplifier only) Frequency analysis range 1/1-octave analysis: 1/3-octave analysis: 16 to 8000 Hz 12.
Specifications Frequency analysis mode (display range 70 dB) 70 to 140 dB 60 to 130 dB 50 to 120 dB 40 to 110 dB 30 to 100 dB 20 to 90 dB 10 to 80 dB Overload indication "Over" indication appears at +8 dB over display full-scale value Under range indication "Under" indication appears at -65 dB below display full-scale value Calibration Electrical calibration with 1000-Hz sine wave signal from built-in oscillator Linearity range All-pass: Spectrum band: 72 dB 77 dB Pulse range All-pass: Spectrum band: 75
Specifications Group store: Capacity: Store intervals: Continuous simultaneous storing of all processing results 200 data sets Equal to processing time Trigger Level trigger, external trigger, time trigger (processing start conditions) Level trigger: *** dB, + or - slope External trigger: Logic-level falling edge Time trigger: Start time and repeat interval settable Delay function Preset delay between start key push or trigger event and actual processing start Delay time range: 0 to 10 seconds in 1-secon
Specifications Microphone 1/2-inch prepolarized condenser type Model: UC-53A Sensitivity: -26.5 dB to -29.0 dB (0 dB = 1 V/Pa) Preamplifier NH-20 Inputs and outputs AC output (main channel and sub channel simultaneous output) Display full-scale point: 1 Vrms Output impedance (main): approx. 600 Ω Output impedance (sub): approx. 600 Ω Load impedance: 10 kΩ or more DC output (main channel and sub channel selectable from menu) Display full-scale point: 3.5 V, 0.5 V/10 dB Output impedance: approx.
Specifications Power requirements Four IEC R14P (size "C") batteries Battery life (at 20ºC, 1/3-octave analysis, continuous operation) Alkaline batteries: approx. 8 hours Manganese batteries: approx. 4 hours External DC power supply 4 to 6 V (from AC adapter NC-94A) Current consumption (at room temperature, 1/3-octave analysis, 5 V): approx. 310 mA Ambient conditions -10 to +50ºC, 30 to 90% RH Dimensions 358 (H) × 100 (W) × 50 (D) mm Weight Approx.
Specifications Supplied accessories Carrying case Windscreen Infrared remote controller Miniature screwdriver Tripod adapter Hand strap (attached) Main batteries Remote controller batteries Backup lithium battery Product name label Instruction Manual Serial Interface Manual Inspection certificate Optional equipment Pistonphone Printer Microphone extension cable Level recorder AC adapter Soft case BNC-to-Pin cable Splitter adapter 146 NA-27-S04 WS-02 NA-27RC1 D-62 NA-27-S05 NA-09-058 IEC R14P IEC R03 CR-1
Specifications Unit: mm Dimensional Drawings 147
No.
