OPERATOR’S INSTRUCTION MANUAL M-2625 AUTO RANGING DIGITAL MULTIMETER with Temperature Probe Copyright © 2007 Elenco® Electronics, Inc.
Contents 1. Safety Information 3,4 2. Safety Symbols 5 3. Front Plate of the Meter Input Terminal Function Rotary Switch Function Press Button LCD Display 5 6 7 8,9 10 4. Power On Option 11 5. Auto Power Off 11 6. Measurement Range 11 7.
Introduction This series LCD auto ranging and auto power-off digital multimeter is a portable, compact, 3¾ digit multimeter. It is ideally suited for field, lab, shop, car, and home. CAUTION: Read, understand and follow all Safety Rules and Operating Instructions in this manual before using this product. 1. Safety Information Use the meter only as specified in this manual. Otherwise, the protection provided by the meter may be impaired. Refer to safety information in Table 1. Table 1.
Table 1. Safety Information (continued) ! Warning • When servicing the meter, use only specified replacement parts. • Use caution when working above 30VAC rms, 42V peak, or 60VDC. Such voltages pose a shock hazard. • Avoid working alone. • When using the probes, keep your fingers behind the finger guards on the probes. • Connect the common test lead before you connect the live test lead. When you disconnect test leads, disconnect the live test lead first.
2. Safety Symbols Symbols used on the meter and in this manual are explained in Table 2. Table 2. International Electrical and Relative Symbols ~ ~ AC (Alternating Current) Important Information ! DC and AC Caution, risk of electric shock DC (Direct Current) Earth Ground Equipment Safety Standard + Double Insulated Low Battery Indicator 3. Front Plate of Meter LCD Display Function Press Button Function Rotary Switch Input Terminal Figure 1.
Input Terminal About terminal function refer to Table 3 and Figure 2. Figure 2. Input Terminal Table 3.
Figure 3. Function Rotary Switch Table 4.
Table 4. Function Rotary Switch Symbols (continued) Position of Switch O F Function µA~ Temperature measurement mA~ DC/AC milliampere current measurement DC/AC microampere current measurement A~ DC/AC ampere current measurement OFF Power off position Function Press Button About press function button refer to Figure 4. Figure 4. Function Press Button 1.
∆ (relative measurement) 3. REL∆ ∆ button to use the relative measuring function and Press the REL∆ a “REL∆” symbol appears on the LCD. The result of the relative measurement is the difference between the measuring value and the reference value. The reference value is produced the same as ∆ button. Press the REL∆ ∆ the momentary value by press the REL∆ button again to exit this function and the “REL∆” symbol disappears from the display.
Figure 5. LCD Display Table 5. LCD Display Symbols Sequ. No. Symbol 1 8.8.8.
Table 5. LCD Display Symbols (continued) Sequ. No. 13 Symbol C O O F 14 % 15 mV / V nF / µF mA / A 16 Description Temperature units (OC not used on this meter) Percent symbol Voltage units Capacitance units Current units Overload 4. Power On Option To release the Auto Power Off function, press and hold the SELECT button when the meter is on. 5. Auto Power Off When the meter has been on for 30 minutes without any action from the user, the meter will automatically switch to the standby mode.
• When you change the measurement function, the meter will regard its auto range as current range. • In the auto range mode, the “AUTO” symbol will appear on display and the manual range disappears. 3. Enter or exit manual range mode • Press the RANGE button to select the manual range mode and the “AUTO” symbol disappears. Each press of the RANGE button increases the range. When the maximum range is reached, the meter restarts at the lowest range.
Measuring DC Voltage 1. Turn on the meter, then set up the meter to measure DC volts as shown in Figure 6. 2. Insert the black test lead into the COM terminal and the red test lead into the terminal. 3. Set the Function Rotary Switch to the ~V position (then, “AUTO” and “mV” symbols are indicated on the display). 4. Connect the black test lead to the negative side of the circuit under test and the red test lead to the positive side of the circuit. The measured value is indicated on the display.
Measuring AC Voltage 1. Turn on the meter, then set up the meter to measure AC volts as shown in Figure 7. 2. Insert the black test lead into the COM terminal and the red test lead into the terminal. 3. Set the Function Rotary Switch to the ~V position and press SELECT to select the AC voltage measuring mode (then, “AUTO”, “AC” and “V” symbols are indicated on the display). 4. Connect the test leads to the circuit under test, then the measured value is indicated on the display. 5.
Figure 7. AC Voltage Measurement Note: When taking a measurement of less than 20mV at the 400mV AC range, the measurement value cannot be indicated correctly. Even if shorted, the input line at the 4V AC range, 1 ~ 3 digits may ∆ button, “0” will remain indicated. In that case, by pressing the REL∆ be indicated.
Measuring Current ! Warning Never attempt an in-circuit current measurement where the open-circuit potential to earth is greater than 300V. You may damage the meter or be injured if the fuse blows during such a measurement. Caution To avoid possible damage to the meter or to the equipment under test, check the meter’s fuses before measuring current. Use the proper terminals, function, and range for your measurement.
Measuring DC Current 1. Turn off power to the circuit. Discharge all high-voltage capacitors. 2. Turn on the meter, then set up the meter to measure DC current as shown in Figure 8. 3. Insert the black test lead into the COM terminal and the red lead into an input appropriate for the measurement range as shown in Table 6. 4. Connect the black test lead to the negative side of the circuit under test and the red test lead to the positive side of the circuit so the meter is in series with the circuit. 5.
Figure 8.
Figure 8. DC Current Measurement (continued) Measuring AC Current 1. Turn off power to the circuit. Discharge all high-voltage capacitors. 2. Turn on the meter, then set up the meter to measure AC current as shown in Figure 9. 3. Insert the black test lead into the COM terminal and the red lead in an input appropriate for the measurement range as shown in Table 6. 4. Connect the test leads to the circuit under test so the meter is in series with the circuit. 5.
Note: To avoid blowing the meter’s 500mA fuse, use the mA terminal only if you are sure the current is less than 400mA. Figure 9.
Figure 9. AC Current Measurement (continued) Measuring Resistance Caution To avoid possible damage to the meter or to the equipment under test, disconnect the circuit power and discharge all high-voltage capacitors before measuring resistance. Resistance is an opposition to current flow. The unit of resistance is the ohm (Ω). The meter measures resistance by sending a small current through the circuit.
1. To measure resistance, turn on the meter, then set up the meter as shown in Figure 10. 2. Insert the black test lead into the COM terminal and the red test lead into the terminal. 3. Set the Function Rotary Switch to the position (then, “AUTO” “OL” and “MΩ” symbols are indicated on the display). 4. Connect the test leads to both ends of the resistance under test, then the measured value is shown on the display.
Testing Diodes Caution To avoid possible damage to the meter or to the equipment under test, disconnect the circuit power and discharge all high-voltage capacitors before testing diodes. Use the diode test to check diodes, transistors, silicon controlled rectifiers (SCRs), and other semiconductor devices. The test sends a current through a semiconductor junction, then measures the junction’s voltage drop. A typical junction drops 0.5V to 0.8V.
Note: Open-circuit voltage between measuring terminals is approximately 1.5V (measuring current approximately 1.5mA). Testing for Continuity Caution To avoid possible damage to the meter or to the equipment under test, disconnect the circuit power and discharge all high-voltage capacitors before testing for continuity. Continuity is the presence of a complete path for current flow. The continuity test features a beeper that sounds if a circuit is complete (the resistance less than 120Ω approx.).
Keep the following in mind while doing a continuity test: • Even with the test leads shorted, the indicated value may not be “0”. This is because of the resistance of the test leads and not a ∆ button to fault. If necessary, you can press the REL∆ automatically subtract its value, then “0” will be indicated. Measuring Capacitance Caution To avoid possible damage to the meter or to the equipment under test, disconnect the circuit power and discharge all high-voltage capacitors before measuring capacitance.
Figure 13.
Measuring Frequency Frequency is the number of cycles a signal completes each second. The meter measures the frequency of a voltage or current signal by counting the number of times the signal crosses a threshold level each second. To measure frequency, proceed as follows: 1. Turn on the meter, then set up the meter as shown in Figure 14. 2. Insert the black test lead into the COM terminal and the red test lead into the terminal. 3.
Measuring Duty Cycle Duty cycle (or duty factor) is the percentage of time a signal is above or below a trigger level during one cycle (Figure 16). To measure duty cycle, proceed as follows: 1. Turn on the meter, then set up the meter as shown in Figure 15. 2. Insert the black test lead into the COM terminal and the red test lead into the terminal. 3. Set the Function Rotary Switch to the Hz position. Then press Hz/DUTY once to select DUTY Cycle measurement (then, a “%” symbol is indicated on the display).
Figure 16. Duty Cycle Measurement Measuring Temperature ! Warning To avoid the potential of fire or electrical shock, do not connect the thermocouples to electrically live circuits. To measure temperature, proceed as follows: 1. Turn on the meter, then set up the meter as shown in Figure 17. 2. Set the Function Rotary Switch to the OF position (then, the “AUTO” and “OF” symbols are indicated on the display). 3.
Figure 17.
8. Maintenance General Maintenance Periodically wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Dirt or moisture in the terminals can affect readings. Clean the terminals as follows: 1. Turn the meter off and remove all test leads. 2. Shake out any dirt that may be in the terminals. 3. Soak a new swab with alcohol. Work the swab around each terminal. Replacing the Batteries Replace the batteries with two “AA” batteries (R6P) or equivalent.
Replacing the Fuses ! Warning To avoid electrical shock or damage to the meter, only use replacement fuses ∅5x20 0.5A/250V FAST or ∅6x25 10A/250V FAST. Referring to Figure 19, examine or replace the meter’s fuses as follows: 1. Turn the Function Rotary Switch to the OFF position and remove the test leads from the terminals. 2. Remove the holster from the meter. Then, using a screwdriver, unscrew the two screws on the back case and remove it. 3.
9. General Specifications Display: 3¾ digit LCD with a maximum reading of 3999. Range Control: Auto range or manual range control. Polarity: Automatic negative polarity indication. Zero Adjustment: Automatic Overrange Indication: Only the “OL” display. Low Battery: The symbol “ + ” is displayed when the battery voltage is below approximately 2.4V. Auto Power Off: 30 minutes after stopping the switch or no keyinput, the meter automatically enters the power off mode. Safety Standards: EMC/LVD.
Table 8. ACV Detailed Accuracy Specifications Range Resolution Accuracy 400mV 4V 40V 400V 600V 0.1mV 1mV 10mV 100mV 1V ±(1.5% rdg + 8) ±(0.8% rdg + 5) ±(1.2% rdg + 5) Note Frequency Response: 50Hz - 400Hz Input Resistance: 10MΩ Overload Protect: 400mV range 250V rms. The rest 600VDC or 600VAC rms. Table 9. DCA Detailed Accuracy Specifications Range Resolution 40µA 0.1µA 400µA 1µA 40mA 10µA 400mA 100µA 4A 1mA 10A 10mA Accuracy ±(2.0% rdg + 5) ±(1.5% rdg + 5) ±(2.
Table 12. Capacitance Detailed Accuracy Specifications Range Resolution Accuracy 40nF 400nF 4µF 40µF 100µF 10pF 100pF 1nF 10nF 100nF ±(3.5% rdg + 10) Note ±(3.0% rdg + 5) Overload Protect: 250V rms ±(3.5% rdg + 5) Table 13. Diode Detailed Accuracy Specifications Range Description Note Display reads approximate forward voltage of diode Forward DC current approx. 1.5mA; Reversed DC voltage approx. 1.5V. Overload protection: 250V rms Table 14.
Elenco® Electronics, Inc. 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Web site: www.elenco.com e-mail: elenco@elenco.
