22-801.fm Page 1 Thursday, December 2, 1999 9:44 AM Cat. No. 22-801 OWNER’S MANUAL Please read before using this equipment.
2-801.fm Page 2 Thursday, December 2, 1999 9:44 AM FEATURES Your RadioShack 35-Range Auto-Ranging Digital Multimeter is a portable, compact multimeter that is ideal for field, lab, shop, bench, and home applications. The meter measures DC and AC current up to 10 A, voltage up to 1000V DC and 750V AC, resistance up to 40 MΩ, and capacitance from 4 nF–40 µF. Its 33/4-digit digital display means it can display up to 3,999 units. Important: • Completely read this manual before you use the meter.
22-801.fm Page 3 Thursday, December 2, 1999 9:44 AM Auto Power Off — the meter helps conserve battery power by sounding a beep then turning off if you do not change any settings for 5 minutes. UL Listed — your meter has passed the stringent safety tests required by Underwriters Laboratories. Note: The UL mark does not indicate that this product has been evaluated by Underwriters Laboratories for the accuracy of its readings.
22-801.fm Page 4 Thursday, December 2, 1999 9:44 AM Low-Battery Indicator — so you can quickly see when you need to replace the batteries. Protective Rubber Boot — protects the meter from damage and lets you hang the meter on a wall. Note: Your multimeter requires one 9V battery (not supplied).
22-801.fm Page 5 Thursday, December 2, 1999 9:44 AM CONTENTS A Word About Safety ............................................................ 6 Special Panel Markings ........................................................ 9 Specifications ..................................................................... 10 Preparation .......................................................................... Installing a Battery ......................................................... Connecting the Test Leads .....
22-801.fm Page 6 Thursday, December 2, 1999 9:44 AM A WORD ABOUT SAFETY We have taken every precaution in designing this meter to ensure that it is as safe as we can make it. But safe operation depends on you, the operator. We recommend that you follow these simple safety rules: • Never apply voltages to the meter that exceed the limits given in the specifications. Never apply more than 1000V DC or 750V RMS AC between the input jacks and ground. • Use extreme caution when working with voltages above 100V.
22-801.fm Page 7 Thursday, December 2, 1999 9:44 AM This meter is fully calibrated and tested. Under normal use, no further adjustment should be necessary except as noted in this Owner’s Manual. If the meter requires repair, do not try to adjust it yourself. Take it to your local RadioShack store. WARNINGS: • USE EXTREME CAUTION IN THE USE OF THIS DEVICE. IMPROPER USE OF THIS DEVICE CAN RESULT IN INJURY OR DEATH.
22-801.fm Page 8 Thursday, December 2, 1999 9:44 AM • ALWAYS WEAR PROTECTIVE LEATHER GLOVES, A FACE SHIELD, AND FIREPROOF ARM AND UPPER BODY PROTECTION WHILE USING THE METER TO MEASURE CURRENT AND VOLTAGE IN COMMERCIAL ELECTRICAL PANELS. • IF THIS EQUIPMENT IS USED IN A MANNER NOT SPECIFIED BY THE MANUFACTURER, THE PROTECTION PROVIDED BY THE EQUIPMENT MAY BE IMPAIRED. • TO REDUCE THE RISK OF FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS PRODUCT TO RAIN OR MOISTURE. • FOR INDOOR USE ONLY.
22-801.fm Page 9 Thursday, December 2, 1999 9:44 AM SPECIAL PANEL MARKINGS For your safety, we have added special markings to the meter’s panel to remind you of the measurement limitations. 10 A MAX UNFUSED The maximum current that you can measure at this terminal is 10 amps. Caution: This terminal is not fuse-protected. 500V MAX To avoid electrical shock or instrument damage, do not connect the common input terminal (–COM jack) to any source that exceeds 500 volts with respect to earth/ground.
22-801.fm Page 10 Thursday, December 2, 1999 9:44 AM SPECIFICATIONS DC VOLTS (MAX MEASUREMENT: 1000V) 400 mV ................................. ±2.5% of full scale, ±2 in last digit 4–40–400 V .......................... ±2.0% of full scale, ±2 in last digit 1000 V ...................................................... ±20 V, ±2 in last digit AC VOLTS (MAX MEASUREMENT: 750 V at 50–100Hz) (AC Average Response, RMS Calibrated, DC Coupled) 400 mV ................................. ±3.
22-801.fm Page 11 Thursday, December 2, 1999 9:44 AM AC CURRENT (MAX MEASUREMENT: 10A AT 60 HZ) (AVERAGE RESPONSE, RMS CALIBRATED, DC COUPLED) 400 µA/40mA ....................... ±3.5% of full scale, ±3 in last digit 4 mA/400mA ........................ ±3.0% of full scale, ±3 in last digit 4A ........................................ ±3.5% of full scale, ±3 in last digit 10 A ..................................... ±3.
22-801.fm Page 12 Thursday, December 2, 1999 9:44 AM CONTINUITY TEST Open Circuit Voltage ...........................................2.5 V (Typical) Short Circuit Current ................................................... < 2.0 mA DIODE TEST The diode test measures the voltage drop across the diode under test. Nominal Current ............................................. 1.0 mA @ 0.60 V 1.1 mA @ 0.0 V (short) 0.0 mA @ 2.5 V (open) Overrange .......................... > 2.0 V DC to Vcc (2.
22-801.fm Page 13 Thursday, December 2, 1999 9:44 AM Overrange Indication .............. O.F (overflow) or OL (overload) Caution: When O.F appears, it indicates that the measurement exceeds the range for the current setting. When OL appears, it indicates that the measurement exceeds the absolute maximum reading. Exceeding the maximum limits of the DC 1000V, AC 750 V, and DC/AC 10 A ranges can damage the meter and cause the meter to not show an overrange indication. Operating Temperature ...................
22-801.fm Page 14 Thursday, December 2, 1999 9:44 AM Weight (without batteries) .................... Approx. 10.6 oz (300 g) Included Accessories ................................................ Test leads Extra 500 mA 250V Ceramic Fuse (such as Littelfuse® 216.500) Specifications are typical; individual units might vary. Specifications are subject to change and improvement without notice.
22-801.fm Page 15 Thursday, December 2, 1999 9:44 AM PREPARATION INSTALLING A BATTERY Your meter requires one 9 volt rectangular battery for power. For the best performance and longest life, we recommend a RadioShack alkaline battery. Warnings: • To avoid electrical shock, disconnect both of the meter’s test leads from any equipment before you install or remove the meter’s battery. • Do not operate your meter until the battery is properly installed and the back cover is in place and secured.
22-801.fm Page 16 Thursday, December 2, 1999 9:44 AM Rubber Boot 1. Turn off the meter if it is not already off (see “Automatic/ Manual Power Off” on Page 28), then disconnect the test leads if they are connected. 2. Lift the stand on the back of the meter, then use a Phillips screwdriver to loosen the screw in the meter’s back cover and lift off the cover. Stand Screwdriver 3.
22-801.fm Page 17 Thursday, December 2, 1999 9:44 AM Note: If the meter automatically turns on, continue with Step 4. If the meter does not automatically turn on, press SELECT. If the meter still does not turn on, press RESET on the circuit board. The meter turns on. RESET 4. Replace the cover and secure it with the screw. When BATT appears on the right side of the display, replace the battery. Warning: Dispose of old batteries promptly and properly. Cautions: • Always remove an old or weak battery.
22-801.fm Page 18 Thursday, December 2, 1999 9:44 AM CONNECTING THE TEST LEADS The test leads supplied with your meter are rated for 1000 volts. Use only test leads of the same rating with the meter. You can order replacement leads from your local RadioShack store. WARNING: ALTHOUGH THE TEST LEADS ARE RATED FOR 1000 VOLTS, THE MAXIMUM RATING OF THIS METER IS 1000 VOLTS DC/750 VOLTS RMS AC. DO NOT TRY TO MEASURE ANY VOLTAGE GREATER THAN 1000 VOLTS DC/750 VOLTS RMS AC.
22-801.fm Page 19 Thursday, December 2, 1999 9:44 AM USING THE STAND The fold-out stand on the back of the meter lets you place the meter upright on a flat surface (as shown here) for easier viewing. USING THE RUBBER BOOT The rubber boot supplied with the meter helps protect the meter from damage. Simply slide the meter into the boot. Use the clips on the back of the boot to store the test leads while you are not using them. The keyhole on the back of the boot lets you hang the meter on a wall.
22-801.fm Page 20 Thursday, December 2, 1999 9:44 AM ABOUT RANGING Your meter sets itself to its automatic ranging mode each time you turn it on. In this mode, the meter automatically selects the next higher or lower range (if available) when the measurement causes the display to overflow (the meter tries to display 4000 or more units) or underflow (the meter tries to display 380 or fewer units). If a voltage or current measurement exceeds 4000 units, the meter might display O.
22-801.fm Page 21 Thursday, December 2, 1999 9:44 AM USING THE METER For the most accurate readings, the temperature should be between 65°F and 83°F (18°C and 28°C), with a maximum of 80% relative humidity. Before you use your meter for the first time, follow these steps to familiarize yourself with its operation. Warning: Always turn off power to the circuit you are about to measure before you probe the test leads into high-voltage points.
-801.fm Page 22 Thursday, December 2, 1999 9:44 AM 3. Repeatedly press RANGE to set the meter to manual ranging so you can view the different measurement ranges. AUTO disappears and the decimal point shifts each time you press RANGE. See “Manually Setting the Range” on Page 24. 4. Turn the selector to change between the meter’s functions and familiarize yourself with the displays. Your meter automatically sets itself to the range that gives the best reading.
22-801.fm Page 23 Thursday, December 2, 1999 9:44 AM Range Display 400 mA ddd.d mA 400 ohms ddd.d Ω 4 KΩ d.ddd KΩ 40 KΩ dd.dd KΩ 400 KΩ ddd.d KΩ 4 MΩ d.ddd MΩ 4V (Fixed Range) d.ddd V Note: The display might show a phantom reading in some DC and AC voltage ranges when the test leads are not connected to a circuit. This is normal. The high input sensitivity produces a “wandering” effect. When you connect the test leads to a circuit, a real measurement appears. 5.
22-801.fm Page 24 Thursday, December 2, 1999 9:44 AM • If OL (overload) appears, the value you are measuring exceeds the meter’s maximum range. Immediately disconnect the probes from the circuit. MANUALLY SETTING THE RANGE When you measure voltages, resistance, or capacitance, your meter is preset to automatically select a measuring range. When you measure current, the meter is preset to automatically select a range within the limits of the selector’s setting.
22-801.fm Page 25 Thursday, December 2, 1999 9:44 AM Note: You cannot change the selected range while the meter is holding a measurement. To cancel hold, press HOLD/ZERO again or set the selector to another setting. DH disappears. ZEROING THE METER/USING RELATIVE MEASUREMENT You can set the meter to have it not show an unwanted value that might appear as a result of internal or other factors, called zeroing.
22-801.fm Page 26 Thursday, December 2, 1999 9:44 AM Caution: Your meter has a circuit to protect the resistance range from over-voltage. However, to prevent accidentally exceeding the protection circuit’s rating and to ensure a correct measurement, never connect the test leads to a source of voltΩ, 0.4/4 mA, 40/400 mA, or age while the selector is set to 4/10A. This could damage the meter or the circuit being tested.
22-801.fm Page 27 Thursday, December 2, 1999 9:44 AM Notes: • If the reference value you measured in Step 2 is greater than the value of the measurement you made in Step 4, the meter shows a negative value. This is not a malfunction. • You must zero the meter or set a new reference value each time you change the range or mode. • The meter automatically sets itself to manual ranging when you use this function. • O.F appears as usual if you measure values outside of the meter’s currently set range.
22-801.fm Page 28 Thursday, December 2, 1999 9:44 AM AUTOMATIC/MANUAL POWER OFF Your meter conserves power by automatically turning off about 5 minutes after the last time you changed settings (even if you are making measurements). OFF appears and the meter beeps as it turns itself off. To turn the meter back on after it automatically turns off, press any button (SELECT, RANGE, or HOLD/ZERO).
22-801.fm Page 29 Thursday, December 2, 1999 9:44 AM MAKING MEASUREMENTS MEASURING DC/AC VOLTAGE Warnings: • Never clamp a test lead to a hot wire (usually red, black, or blue in AC wiring circuits). If one lead is clamped to a hot wire and you touch the meter’s other probe, you could receive an electric shock. • The maximum input limit for voltage measurement is 1000V DC or 750V AC (RMS).
22-801.fm Page 30 Thursday, December 2, 1999 9:44 AM When you measure DC voltages, the left side of the display. does not appear on Note: In the 400 V and 400 mV ranges, the decimal point appears in the same position (one place to the left). To distinguish between the two ranges, mV appears in the 400 mV range, and V appears in the 400 V range.
22-801.fm Page 31 Thursday, December 2, 1999 9:44 AM 2. Set the selector to V . 3. Hold down SELECT to set the meter to measure DC voltage ( disappears). 4. Touch the test leads to the circuit you want to test and note the reading. The display shows the DC voltage. 5. Disconnect the test leads from the circuit. 6. Remove power from the circuit under test and discharge all capacitors. 7. Hold down SELECT to set the meter to measure AC voltage ( appears). 8. Connect a 0.
22-801.fm Page 32 Thursday, December 2, 1999 9:44 AM Measuring Three-Phase AC Voltage We designed this meter primarily to measure household AC voltages. If you want to measure 3-phase, line-to-line voltages, please note the following: • Because of the dangers inherent in measuring three-phase circuits, we strongly recommend you do not use this meter for such applications. • The actual voltage can be greater than the circuit’s rated line-to-ground voltage.
22-801.fm Page 33 Thursday, December 2, 1999 9:44 AM MEASURING CURRENT To measure AC or DC current, you must break the circuit and connect the test leads to two circuit connection points. The connection must be in series with the circuit under test. Warning: The meter’s internal components might become dangerously hot if you measure current in the 10 A DC/AC range. Make measurements within 30 seconds after you connect the meter to the circuit and allow the meter to cool for 15 minutes between measurements.
22-801.fm Page 34 Thursday, December 2, 1999 9:44 AM 5. Connect the meter’s test leads in series with the circuit. 6. Apply power and read the current. 7. If the measurement is less than 400 mA, the red test lead is connected to 10A MAX, and the selector is set to 4/10A: • a. Remove power from the circuit • b. Move the red test lead to the +V.mA.Ω jack • c. Set the selector to 40/400 mA • d. Reapply power to the circuit.
22-801.fm Page 35 Thursday, December 2, 1999 9:44 AM • The 0.4/4 mA and 40/400 mA ranges are fuse-protected. If the meter does not show a reading in these ranges, check the fuse (see “Replacing the Fuse” on Page 42). MEASURING RESISTANCE The resistance measuring circuit in your meter compares the voltage gained through a known resistance (internal) with the voltage developed across an unknown resistance.
22-801.fm Page 36 Thursday, December 2, 1999 9:44 AM Note: With no resistance connected across the test leads (meaning resistance is infinite), O.F appears when you set the meter to measure resistance. This is normal. 4. Touch the test leads across the circuit you want to measure, or remove one of the leads of the component you want to measure from its circuit and touch the test leads across the component. If the meter is set to automatic range control, it automatically moves to the proper range.
22-801.fm Page 37 Thursday, December 2, 1999 9:44 AM MEASURING CAPACITANCE The capacitance measuring circuit in your meter charges a connected capacitor to a specific voltage level, then discharges the capacitor to a lower voltage. The meter measures the amount of time it takes to discharge the capacitor. 1. Remove all power from the circuit under test and discharge all capacitors. 2. Set the selector to Ω. 3. Hold down SELECT to set the meter to measure capacitance.
22-801.fm Page 38 Thursday, December 2, 1999 9:44 AM Since this meter cannot use high voltage to set the electrolyte, it cannot measure the absolute value of capacitance. • Low value capacitors might match or be close to the actual input capacitance of your meter. To measure low capacitance values, use the meter’s zero feature to adjust the meter for the meter’s own capacitance (see “Zeroing the Meter/Using Relative Measurement” on Page 25).
22-801.fm Page 39 Thursday, December 2, 1999 9:44 AM CHECKING DIODES This procedure lets you check diodes, transistors, and other semiconductors for opens, shorts, and normal operation. It also lets you determine the forward voltage and polarity for diodes. (This is handy when you need to match a diode.) You can also check LEDs using this procedure. Caution: Do not connect the test leads to a source of voltage with the selector set to . This could damage the meter or the circuit being tested. 1.
22-801.fm Page 40 Thursday, December 2, 1999 9:44 AM Notes: • When you test a silicon-type semiconductor, the values might vary depending on the temperature. • The values that appear during a diode check show the actual forward voltage (max. 2.0V). If the voltage exceeds 2.0V, O.F appears. This means the diode check cannot be made using this meter. Checking Diode Polarity Many diodes have a stripe or mark on one side. The marked side of the diode indicates the diode’s cathode or negative (–) side.
22-801.fm Page 41 Thursday, December 2, 1999 9:44 AM CARE AND MAINTENANCE Your RadioShack 35-Range Auto-Ranging Digital Multimeter is an example of superior design and craftsmanship. The following suggestions will help you care for your meter so it will serve you for years. Keep the meter dry. If it gets wet, wipe it dry immediately. Liquids might contain minerals that can corrode the electronic circuits. Use and store the meter only in normal temperature environments.
22-801.fm Page 42 Thursday, December 2, 1999 9:44 AM Modifying or tampering with the meter’s internal components can cause a malfunction and might invalidate its warranty. If your meter is not performing as it should, take it to your local RadioShack store for assistance. CLEANING To keep the meter looking new, occasionally wipe it with a cloth slightly dampened with water. Do not use harsh chemicals, cleaning solvents, or strong detergents to clean the meter.
22-801.fm Page 43 Thursday, December 2, 1999 9:44 AM The fuse is a 500 mA, 250V ceramic fuse (such as Littelfuse® 216.500). Caution: Do not use a fuse with ratings other than those specified here. Doing so might damage your meter. Follow these steps to replace the fuse. 1. Turn the meter off if it is not already off (see “Automatic/ Manual Power Off” on Page 28), then disconnect the test leads if they are connected.
22-801.fm Page 44 Thursday, December 2, 1999 9:44 AM 4. If the fuse is blown, discard it and save the ribbon (to use with the next spare fuse you store in the compartment). Then remove the spare fuse and the ribbon holding it from beside the battery compartment and insert it into the fuse holder. 5. Replace the back cover and secure it with the screw. Warning: Do not operate your meter until the back cover is in place and secured.
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22-801.fm Page 48 Thursday, December 2, 1999 9:44 AM Limited Ninety-Day Warranty This product is warranted by RadioShack against manufacturing defects in material and workmanship under normal use for ninety (90) days from the date of purchase from RadioShack company-owned stores and authorized RadioShack franchisees and dealers.
