Related Manuals for Radio Shack 22-178
Summary of Contents for Radio Shack 22-178
- Page 1 22-178.fm Page 1 Friday, August 6, 1999 11:38 AM Cat. No. 22-178 OWNER’S MANUAL Please read before using this equipment. Auto-Ranging LCD Digital Multimeter...
- Page 2 22-178.fm Page 2 Friday, August 6, 1999 11:38 AM CAUTION RISK OF ELECTRIC SHOCK. DO NOT OPEN. CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER OR BACK. NO USER-SERVICE- ABLE PARTS INSIDE. REFER SERVIC- ING TO QUALIFIED PERSONNEL.
- Page 3 22-178.fm Page 3 Friday, August 6, 1999 11:38 AM FEATURES Your RadioShack Auto-Ranging LCD Digital Multimeter is a portable 3 -digit, compact multimeter that is ideal for field, lab, shop, bench, and home applications. Here are some features that make your new digital multimeter a real pro.
- Page 4 22-178.fm Page 4 Friday, August 6, 1999 11:38 AM Data Hold Function — holds the display so you can see the reading even after you disconnect the probes. Overload and Transient Protection — helps protect the meter from overvoltage in most ranges.
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Page 5: Table Of Contents
22-178.fm Page 5 Friday, August 6, 1999 11:38 AM CONTENTS A Word About Safety ..........6 Specifications ............. 8 Special Panel Markings ..........12 Preparation ..............13 Installing Batteries ..........13 Using Test Leads ..........14 Using Alligator Clips ..........15 Using the Stand and Holster ........ -
Page 6: A Word About Safety
22-178.fm Page 6 Friday, August 6, 1999 11:38 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: •... - Page 7 22-178.fm Page 7 Friday, August 6, 1999 11:38 AM • Because many AC/DC sets have a potentially hot chassis, be sure the top of your workbench and the floor underneath it are made of non-conductive mate- rials. • The multimeter is fully calibrated and tested. Under normal use, no further adjustment should be neces- sary.
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Page 8: Specifications
22-178.fm Page 8 Friday, August 6, 1999 11:38 AM SPECIFICATIONS Display ........LCD 3 -digits maximum, 3200 count resolution Bar Graph ........... 33 segments (100 counts of resolution/segment sampled 12 times/second) RANGES AND ACCURACY DC Volts 300 mV–3 V ........ - Page 9 22-178.fm Page 9 Friday, August 6, 1999 11:38 AM DC Current A/30 mA ........1.0% of reading, ± 0.2% of full scale, 1 in last digit ± ± 3000 A/300 mA 1.5% of reading, ........± 0.2% of full scale, 1 in last digit ±...
- Page 10 22-178.fm Page 10 Friday, August 6, 1999 11:38 AM Resistance 300 ohms–3–30–300 kohms ....1.0% of reading, ± 0.2% of full scale, 1 in last digit ± ± 3 M ohms ..........2.0% of reading, ± 0.2% of full scale, 1 in last digit ±...
- Page 11 22-178.fm Page 11 Friday, August 6, 1999 11:38 AM Overrange Indication (overload) ..... OL. appears on the display to indicate that the measurement exceeds the absolute maximum reading. Use care in DC1000V, AC 750 V, and DC/AC 20 A ranges, as exceeding the maximum limits of these ranges can dam- age the meter and prevent an overrange indication.
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Page 12: Special Panel Markings
22-178.fm Page 12 Friday, August 6, 1999 11:38 AM SPECIAL PANEL MARKINGS For your safety, we have added special markings to the panel to remind you of the measurement limitations. 20 A The maximum current that you can mea- sure at this terminal is 20 amps. -
Page 13: Preparation
22-178.fm Page 13 Friday, August 6, 1999 11:38 AM PREPARATION INSTALLING BATTERIES Your meter requires two AA batteries for power. We rec- ommend alkaline batteries, such as RadioShack Cat. No. 23-557. 1. Turn off the power and disconnect the test leads. -
Page 14: Using Test Leads
22-178.fm Page 14 Friday, August 6, 1999 11:38 AM 6. Replace the meter in the holster. When appears on the right side of the display, re- place the batteries. Warnings: • To avoid electrical shock, disconnect both test leads from any equipment before you remove the batteries. -
Page 15: Using Alligator Clips
22-178.fm Page 15 Friday, August 6, 1999 11:38 AM Caution: Although these test leads are rated for 1200 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. -
Page 16: Using The Stand And Holster
22-178.fm Page 16 Friday, August 6, 1999 11:38 AM USING THE STAND AND HOLSTER The fold-out stand lets you place the meter upright on a flat surface for easier viewing. (illus of meter w/stand and hanging) The holster lets you hang the meter on a wall, hold the... -
Page 17: Using The Meter
22-178.fm Page 17 Friday, August 6, 1999 11:38 AM USING THE METER Before you use the meter the first time to make a mea- surement, follow these steps to confirm correct operation and to familiarize yourself with the meter’s operation. -
Page 18: Taking Accurate Measurements
22-178.fm Page 18 Friday, August 6, 1999 11:38 AM Notes: • See the unit of measure on the display to distinguish the range. For example, the meter displays in the 300 mV range and in the 300 V range. Also, note the position of the decimal. -
Page 19: Automatic Power Off
22-178.fm Page 19 Friday, August 6, 1999 11:38 AM Connect the red lead to the terminal V•W• •mA•mA• and the black lead to the terminal. All connections except 20 A measurements are made at these terminals. Caution: When (overload) appears on the display, the value you are measuring exceeds the meter’s maxi-... -
Page 20: Manually Setting The Range
22-178.fm Page 20 Friday, August 6, 1999 11:38 AM MANUALLY SETTING THE RANGE When you measure voltages or resistance, your meter can automatically select a measuring range. When you measure current, the meter automatically selects a range within the limits of the selector’s setting. While this fea-... -
Page 21: Using The Bar Graph
22-178.fm Page 21 Friday, August 6, 1999 11:38 AM To cancel data hold, press again or move the se- DATA-H lector. USING THE BAR GRAPH The meter also indicates all the measurements on the bar graph at the bottom of the display. The bar graph’s length increases and decreases with the measured val- ue. -
Page 22: Making Measurements
22-178.fm Page 22 Friday, August 6, 1999 11:38 AM MAKING MEASUREMENTS MEASURING DC/AC VOLTAGE Caution: The maximum input limit for voltage measure- ment is 1000V DC and 750V AC (RMS). If you try to mea- sure a DC voltage above 1000 volts or an AC voltage above 750 volts RMS, you can damage your meter. - Page 23 22-178.fm Page 23 Friday, August 6, 1999 11:38 AM Hint: When you use the meter to probe for a voltage in a high-voltage circuit, we recommend you do not try to position both probes at once. Instead, use one of the supplied insulated alligator clips to clamp one lead to the circuit’s neutral or ground lead (usually a...
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Page 24: Measuring An Ac Voltage Riding On A Dc Source Bias
22-178.fm Page 24 Friday, August 6, 1999 11:38 AM MEASURING AN AC VOLTAGE RIDING ON A DC SOURCE BIAS (illustration) To measure an AC voltage superimposed on a DC volt- age source bias, you must first measure the DC and AC... -
Page 25: Measuring Three-Phase Ac Voltage
22-178.fm Page 25 Friday, August 6, 1999 11:38 AM Measuring Three-Phase AC Voltage We designed this meter primarily to measure household AC voltages. It is not intended for commercial or industri- al use. Please note the following about 3-phase, line-to- line voltages. -
Page 26: Measuring Dc/Ac Current
22-178.fm Page 26 Friday, August 6, 1999 11:38 AM MEASURING DC/AC CURRENT To measure current, you must break the circuit and con- nect the leads to two circuit connection points. The con- nection must be in series with the circuit under test. Use the supplied alligator clips for this connection. - Page 27 22-178.fm Page 27 Friday, August 6, 1999 11:38 AM 3. Plug the black test lead into the jack and the red test lead into the appropriate jack. 4. Remove power from the circuit under test and dis- charge all capacitors.
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Page 28: Measuring Resistance
22-178.fm Page 28 Friday, August 6, 1999 11:38 AM MEASURING RESISTANCE The resistance-measuring circuit compares the voltage gained through a known resistance (internal) with the voltage developed across an unknown resistance. 1. Remove all power from the circuit under test and dis- charge all capacitors. -
Page 29: Checking Continuity
22-178.fm Page 29 Friday, August 6, 1999 11:38 AM Caution: The meter has a circuit to protect the resistance range from over-voltage (450 volts RMS AC, 1 minute). However, to prevent accidentally exceeding the protec- tion circuit’s rating and to ensure a correct measurement,... -
Page 30: Checking Diodes
22-178.fm Page 30 Friday, August 6, 1999 11:38 AM 2. Press appears on the display. Caution: NEVER CONNECT THE PROBES TO A SOURCE OF VOLTAGE while the selector is set to 3. Plug the red test lead into the jack V•W•... - Page 31 22-178.fm Page 31 Friday, August 6, 1999 11:38 AM 3. Plug the red test lead into the jack V•W• •mA•mA• and the black lead into the jack. 4. Remove power from the circuit under test and dis- charge all capacitors.
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Page 32: Maintenance
22-178.fm Page 32 Friday, August 6, 1999 11:38 AM MAINTENANCE Your RadioShack Auto-Ranging LCD Digital Multimeter is an example of superior design and craftsmanship. The following suggestions will help you care for the meter so that you can enjoy it for years. -
Page 33: Fuse Replacement
22-178.fm Page 33 Friday, August 6, 1999 11:38 AM Modifying or tampering with your meter’s internal compo- nents can cause a malfunction and might invalidate the meter’s warranty. If your meter is not performing as it should, take it to your local RadioShack store for assis- tance. - Page 34 22-178.fm Page 34 Friday, August 6, 1999 11:38 AM Follow these steps to replace any blown fuse. 1. Turn off the power and disconnect the test leads. 2. Remove the screw securing the back case and lift off the back cover.
- Page 35 22-178.fm Page 35 Friday, August 6, 1999 11:38 AM NOTES...
- Page 36 22-178.fm Page 36 Friday, August 6, 1999 11:38 AM RadioShack Limited Warranty This product is warranted against defects for 90 days from date of pur- chase from RadioShack company-owned stores and authorized RadioShack franchisees and dealers. Within this period, we will repair it without charge for parts and labor.