LTL2000S / SQ RETROREFLECTOMETER Manual DELTA ⋅ Venlighedsvej 4 ⋅ DK-2970 Hørsholm ⋅ Denmark ⋅ Tel. (+45) 72 19 40 00 ⋅ Fax (+45) 72 19 40 01 ⋅ www.delta.
DISCLAIMER The information contained in this document is subject to change without notice. DELTA LIGHT & OPTICS MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. DELTA LIGHT & OPTICS SHALL NOT BE LIABLE FOR ERRORS CONTAINED HEREIN OR FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, PERFORMANCE OR USE OF THIS MATERIAL. Rev. 080104 SW ver: 1.
INDEX SECTION 1................................................................................................................................ 1 INTRODUCTION............................................................................................................................. 1 Introduction ................................................................................................................................................... 1 LTL2000S(Q) features ..........................................
APPENDIX C .......................................................................................................................... 40 SPECIFICATION........................................................................................................................... 40 General Characteristics Rl ........................................................................................................................... 40 General Characteristics Qd.......................................................
SECTION 1 INTRODUCTION Introduction This manual covers both LTL2000S and LTL2000SQ. Some functions will only be available on LTL2000SQ and will be printed in blue colour. The LTL2000S is a portable field instrument, intended for measuring the reflection properties of road markings “Rl” as seen in the vehicle headlight illumination. To measure the Rl properties (coefficient of retro reflected luminance) the road is illuminated at an angle of 1.24 deg. and the reflected light is measured at an angle of 2.
Serial communication on RS232 port gives extended command, calibration, diagnostics and data dump facilities. The LTL2000S(Q) is powered by a rechargeable lead acid battery, giving several hours of measurement capacity. A mains powered battery charger is supplied as standard.
Getting started Buttons Measure Menu Enter Home Calibrate Print Sc roll down Scroll up OFF ON Measuring Turn the instrument on by pressing and holding the Retrometer LTL2000SQ v1.6 button until the LCD shows: Retrometer 2004-01-08 10:55 Calibrate the instrument if necessary, see Calibration page 6. Place the instrument on the road marking. Press the key. The measurement will start instantly. Duration approx. 3 sec. depending on measurement mode (approx. 5. sec when measuring both Rl and Qd).
scroll through the status list to see the possible cause of the problem. For further description on the error messages see Status Display page 19. Alternatively or select the menu Print Status to print a complete instrument status. Note: When battery voltage becomes low a warning (W) is shown in the lower right corner of display. It is still possible to take measurements but when the voltage drops too low, readings can be erroneous.
the Mean calculation function is enabled and there is more than 1 measurement in the calculation then the number of measurements is shown first. Scroll Keys: In normal mode the key activates the Clear Top Log function, in menu mode it is used to scroll through the menu functions and to increment shown values. In normal mode the key activates the Edit Sequence Id function, in menu mode it is used to scroll through menu functions and to decrement shown values.
Calibration - LTL2000S A calibration should always be carried out before starting a new series of measurements. Calibration is done by placing the calibration unit underneath the instrument between the rails. The easiest way to place the unit is to tilt the instrument backwards. Figure 1. How to tilt the instrument. The calibration units are fitted with guidance pins on the outside. The pins mounted in the middle of the longitudinal direction of the unit shall fit in the notch in the rails.
The display shows: Step 1 Mount Light Trap when Ready Step 2 Step 3 Zeroing Please Wait Step 6 Rl Normal 150 = OK to Edit Wait Zero OK Zero: 0.05% Step 4 Step 5 Mount Rl Normal when ready Calibrating Please Wait Step 7 Step 8 Rl Normal 150 = when OK Calibration Done Remove Normal To verify the calibration do a Rl measurement on the normal before removing the normal in step 8. To document the calibration press the key to print.
Calibration - LTL2000SQ A calibration should always be carried out before starting a new series of measurements. The LTL2000SQ is supplied with two calibration units. One for Rl and one for Qd. The order of R1 / Qd calibration is not critical. Qd calibration can be done before the Rl calibration and reverse. The Rl / Qd calibration can also be performed individually. The Qd calibration only consist of one calibration (no zero calibration is needed).
If the key is pressed the calibration result is printed. In the example above the Qd function is now calibrated to a Qd value of 215. If an error is detected during the calibration procedure then the display will indicate this. Rl Calibration: See Rl calibration page 6. Rail Guidance pin placed in notch The normal must be placed with this side up for the different calibrations. Zero calibration for the Rl calibration (step 1 in the detailed description page 5).
Remember: DELTA Recharge battery when possible. Never leave battery discharged for longer periods of time. Keep protection window, light trap and calibration unit clean. LTL2000S(Q) is an optical precision instrument, handle with care.
SECTION 2 GENERAL INFORMATION Rl Measurement The Rl part of the LTL2000S(Q) Retroreflectometer measures the Rl (coefficient of retro reflected luminance) parameter. The Rl parameter represents the brightness of the road markings seen by drivers of motor vehicles by headlight illumination. The illumination angle is 1.24° and the observation angle is 2.29° simulating a drivers viewing distance of 30 metres at an eye height of 1.2 metres. The observation area is app. 45 mm. x 200 mm.
The illuminations field with a length of 200mm length and 43 mm wide gives a large measuring measurement field of 85 cm2. Combined with an observation field of 350 mm length this gives a considerable capability to measure profiled and textures makings but also a high reliability for obtaining correct readings for un even surfaces or if small debris are present at one of the instruments support pads on the marking.
R L of a road marking 500 be am s 400 se pa rat ing 300 200 100 0 0 1 2 3 4 5 H (mm) H Figure 4: Simulation of profiled markings and/or un-even markings: Lift of a retroreflectometer to a height H and the resulting RL values.
up to 5 mm profile height up to 20 cm profile gap Figure 5: The reach of the LTL 2000S(Q) makes it capable of measuring profiled road markings of profile height up to 5 mm, or profile gap up to 20 cm. The advantage of the DELTA optical arrangement with a smaller illumination field in a large measurement field is illustrated in the figure 6 below compared to a system with two identical fields. Pro profiled/textures markings, on even markings and in situations where a small debris (e.g.
Before tilt /shift of high position LTL2000 5 mm profile capability. Competitor < 0.5 mm profile capabilty After tilt/shift of high position LTL2000 5 mm profile capability. Competitor < 0.5 mm profile capabilty Area not measured Figure 6: The LTL2000S(Q) illuminations/measurement fields ( 5mm profile capability) compared to a system with identical fields (< 0.
515 516 517 518 512 512 Road marking surface – – Light source Diffusing box with white interior finish Thin perforated plate Aperture into diffusing box 517 518 Figure 7.
Instrument function Physically the instrument is dominated by the “control tower”. The tower contains the Rl illuminating and observation system and the control electronics. The unit on top of the base structure contains the Qd illumination system, the observation system is the same for both Rl and Qd. The base structure contains an optical system with mirrors that directs Rl illumination beam towards the road surface and the Rl or Qd signal to the detector through a dust-protection window.
The LTL2000S(Q) is factory calibrated. Nevertheless start important measurements with a calibration. Study the Retroreflectometer status and error messages if any. See also Section 4 – Maintenance (page 25). When the battery voltage becomes low a warning is shown in the display (W). It is still possible to take measurements but when the voltage drops further, readings can be erroneous. If in doubt whether the readings are correct make a control measurement on the calibration unit.
SECTION 3 KEYBOARD, DISPLAY AND FUNCTIONS Keyboard Layout . . . . . . Figure 8. Keyboard. Keyboard functions Key Label Key Function Turns the instrument On. Hold activated until the sign on message appears in the Display. Turns the instrument Off. Terminates all activity and powers off. Take a measurement and show the result in the display. All relevant data is automatically stored in the data log for later print or dump to the communication port. Enter calibration menu.
Enter - Activates selected function, accepts changed settings and confirms choices. Home (Home position) - Cancels selected function or menu and return to top control level displaying the latest measurement result. Outputs the latest measurement or calibration result to the printer. Printout has to finish completely before any other function can be selected.
Entering Measurement id: To enter / edit the sequence id press the button when in home position. Use the button to scroll through the alphabet in direction A..Z (starting with the space character), 0..9. The button will scroll through the alphabet in opposite direction. When the wanted character is shown press the button to advance to the next position. You have to step through all 6 positions before the sequence id function will be accepted.
the display one at a time using the keys. An * after a text means that the message only is shown at special occasions e.g. an error or warning! LTL2000S(Q) Display Explanation (The following messages are possible) R: 146 Q: 64 The latest measurement results. Rl Signal: 143 The measured Rl “raw signal” level. Rl Out of Limit* The Rl value is negative.
LTL2000S(Q) Display Explanation (The following messages are possible) Qd Out of Limit* The Qd value exceeds the theoretical value of 318. Qd Sig Overflow* See Rl Sig Overflow. Qd Stray L: 0 The measured Qd stray light level. Qd High Stray L* See Rl High Stray L. VBat Qd: 11.3V See VBat Rl. Low VBat Warning* VBat idle: 12.6V Low VBat Warning* DELTA The battery idle voltage is measured just before the lamp was turned on.
• Disable Id Clear the measurement id. • Free Log Shows the numbers of free log positions in the log. Pressing will clear the log. In order to avoid accidental erasing the log, a second is required. • Print Log Output all the data in the log to the printer. Press to select. The display now shows the number of measurements in the data log. Press to start printing. The print process continues until all the data has been printed (newest first). The only way to stop is to turn the instrument off.
SECTION 4 MAINTENANCE General care The Retroreflectometer is constructed for outdoor use in ordinary good weather conditions. It will stand moist weather with wet roads, but caution must be taken against rain or splashes and dirt from traffic. The LTL2000S(Q) Retroreflectometer is an optical instrument and shall be handled as such. Avoid shock and vibration if possible. Note Keep dust/protection window and light trap clean Protection window The protection window is located in the optical unit.
Fuses Fuses, two pieces, are placed at the rear of the instrument. The charging fuse protects the battery against short circuit and other errors in the charging connector, charger or charging system. The battery fuse protects battery and electronics against short circuit and other errors in the electronic system. Always replace a blown fuse with one of equal rating. To change a fuse carefully unscrew the plastic cap fuse holder by using e.g. a coin.
mild household detergent. To ensure reliable measurements, it is recommended that the calibration unit is periodically recalibrated to a traceable standard. DELTA Light & Optics offers calibration traceable to PTB (Physikalsich-Technishe Bundesanstalt). For information contact your distributor or DELTA Light & Optics. Light trap Zero signals are simulated by a light trap made of two glossy and black plastic sheets mounted in an acute angle. If clean this will provide very efficient light absorbing device.
Printer The printer is a high speed high quality mini thermal printer. It has only a few moving parts and does not require any special or periodic maintenance. Paper specification: • thermal paper • width: 57.5 mm • diameter: 31 mm (max.) Replacing the paper is easily done by opening the paper container with the little handle in the cover, just place the new paper role with a short paper tail hanging out at the top and close the cover with a firm push. Figure 12. How to replacing the printer paper.
APPENDIX A COMMUNICATION FACILITIES RS-232C specification The LTL2000S(Q) is equipped with a communication facility that enables the use of a simple data terminal or an ordinary PC type computer for control of LTL2000S(Q) functions and for log data acquisition. The computer or terminal connects to the Instrument using a communication cable fitted with a 9 pin male D-Sub connector at one end and a 9 or 25 pin connector at the other end. The electrical connections meet the EIA/TIA-232E and CCITT V.
Connections in the 9 pin D-Sub connector. pin # Function Signal Direction 3 Receive Data Data to LTL2000S(Q) 2 Transmit Data Data from LTL2000S(Q) 5 Signal Ground Signal Ground Connection example #1. PC with 25-pin D-Sub communication port.
Connection example #2. PC with 9 pin D-Sub communication port. Cable connections: PC Port DTE pin name LTL DTE 1 CD X 2 RxD -- 2 3 TxD -- 3 4 DTR X 5 SG -- 6 DSR X 7 RTS X 8 CTS X 9 RI X 9-pin female D-SUB 5 9-pin male D-SUB As it can be seen, the interconnections have been held to an absolute minimum, and in some rare situations there will have to be established additional connections on the PC side. Please refer to your PC manual for further information.
Command format All LTL2000S(Q) commands are built using the following template. Command (one ore more letters) Delimiter (one ore more spaces, optional) Parameter (Integer or Real number, optional) Command End (Carriage Return, mandatory) Example #1: The user wants to see how the Automatic Off timer is set and then change the value to 120 seconds. The command and the response sequence look like this. Ot Automatic Off Timer = 300 sec.
Command set The instrument is equipped with a serial communication port primarily for log data acquisition, calibration and test, however all normal instrument functions can be controlled from this interface.
Command set Command Parameter OTn None 59 180 None None 123 PV QCn QEn RCn REn Response Rl Status Code 0 00000000 2002 Aug 12 13:53:19 LTL2000SQ v1.0 s/n:n Off Timer = 300 sec. Off Func: Off Off Timer: = 180 sec. V_PMT = 644 Volt QdF: 0.1366 Cal Qd? [Y/N] Cal Qd! Qd Factor = 0.7564 Qd Normal = 123 Qd On Qd Off Qd On RlF: 2.038 Cal Rl [Y/N] Cal Rl Rl Factor = 2.
Command set Command TO Parameter None Response Sensor Off Meaning Turn sensor off (power off) VAn VB VS None 11.50 None None VBat Alarm: 11.00 Volt VBat Alarm: 11.50 Volt VBat = 12.77 Volt VBat Lamp Off: 12.78 Volt VBat Rl Lamp On : 11.99 Volt VBat Qd Lamp On : 12.09 Volt Set point for low bat warning New set point for low bat warning Measure actual voltage on lead-acid battery Measured VBat with min. load Measured VBat with Rl.
APPENDIX B Status code interpretation Rl Status code interpretation: bit pattern value Status Code: 00000001 1 Status Code: 00000010 2 Status Code: 00000100 4 Status Code: 00001000 8 Status Code: 00010000 16 Status Code: 00100000 32 Status Code: 01000000 64 Status Code: 10000000 128 Description Error in Rl Result Stray Light Warning Log full Warning Not defined Low Battery Warning High Zero signal Warning High Signal with Lamp on Error High Signal with Lamp off Error Qd Status code interpretation: Status
APPENDIX C Print outs Result Printout Examples of result printouts showing the measured values, the Measurement Id and the number of measurements with this id, the number of measurements used to calculate the mean value, the date and time the measurement was taken, the number of data in the data log, the measurement status and the instrument serial number. Note that one or more of the shown data can be left out depending on the selected operation mode.
Note: The Calibration printout can only follow directly after a calibration with the key. Log Printout Example of log printout from LTL2000SQ The printout shows the instrument s/n, number of entries, number of free log entries, a data header and then all the data listed with the newest first, if one of the measurement modes has been disabled the result entry will show “off” for that measurement. The printout is done from the Menu system.
Status Printout Example of status printout. The printout is done from the Menu system.
APPENDIX C SPECIFICATION General Characteristics Rl Illumination angle to the road ......................................................................................... 1.24º Observation angle to the road.......................................................................................... 2.29º Equivalent observer distance............................................................................................30 m Observation angular spread ......................................................
Electrical Characteristics EMC ..................................................................................................................... EN 50081-1 EN 50082-1 Power supply: Battery.................................................................... Build in 12 volt 3.5Ah sealed lead acid External charger............................................................................... 100-240 V~/ 50-60 Hz Charging time ................................................................................
