User's Guide Digital Multimeter Model MN42
Introduction Congratulations on your purchase of the Extech MN42 MultiMeter. The MN42 offers AC/DC Voltage, DC Current, and Resistance testing. Proper use and care of this meter will provide many years of reliable service. Safety This symbol adjacent to another symbol, terminal or operating device indicates that the operator must refer to an explanation in the Operating Instructions to avoid personal injury or damage to the meter.
Controls and Jacks 1 1. Non-Contact Voltage Sensor 2. LCD Display 3. Function switch 2 4. Positive jack 5. COM jack 6. 10A jack Note: Tilt stand, fuse, and battery compartment are on rear of unit. 3 4 5 6 Symbols •))) Continuity Diode µ micro (amps) m milli (volts, amps) k kilo (ohms) Ω Ohms Alternating (AC) current Direct (DC) current BAT + - Battery test Low battery icon 3 MN42-EU - V1.
Operating Instructions NON-CONTACT VOLTAGE (NCV) WARNING: Always test the NCV function on a know live circuit before use 1. Turn the rotary switch to any measurement position 2. Hold the top of the meter very close to the voltage source as shown. 3. If voltage is present, the LED above the display will glow and the meter will buzz. NOTE: The detector is designed with high sensitivity. Static electricity or other sources of energy may randomly trip the sensor. This is normal operation.
DC VOLTAGE MEASUREMENTS CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or OFF. Large voltage surges may occur that can damage the meter. 1. 2. 3. 4. Set the function switch to the highest VDC position. Insert the black test lead banana plug into the negative COM jack. Insert the red test lead banana plug into the positive V jack. Touch the black test probe tip to the negative side of the circuit. Touch the red test probe tip to the positive side of the circuit.
RESISTANCE MEASUREMENTS WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all capacitors before taking any resistance measurements. 1. 2. 3. 4. Set the function switch to the highest Ω position. Insert the black test lead banana plug into the negative COM jack. Insert the red test lead banana plug into the positive Ω jack. Touch the test probe tips across the circuit or part under test.
DIODE TEST 1. 2. 3. 4. 5. Set the function switch to the position. Insert the black test lead banana plug into the negative COM jack and the red test lead banana plug into the positive jack. Touch the test probes to the diode under test. Forward voltage will indicate 400 to 700mV.Reverse voltage will indicate “1”. A shorted diode will indicate the same value of resistance in both the reverse and forward test directions. Shorted diodes will indicate near 0mV.
Maintenance WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before removing the back cover or the battery or fuse covers. WARNING: To avoid electric shock, do not operate your meter until the battery and fuse covers are in place and fastened securely. This MultiMeter is designed to provide years of dependable service, if the following care instructions are performed: 1. 2. 3. 4. 5. 6. KEEP THE METER DRY. If it gets wet, wipe it off.
Range Specifications Function Range Resolution DC Voltage 200mV 0.1mV (V DC) 2000mV 1mV 20V 0.01V 200V 0.1V 600V 1V AC Voltage (VAC) 50/60Hz 200V 0.1V ±(1.2% reading + 10 digits) 600V 1V ±(2.0% reading + 4 digits) DC Current 2000µA 1µA (A DC) 20mA 10µA 200mA 100µA ±(1.5% reading + 2 digits) 10A 10mA ±(2.0% reading + 2 digits) 200Ω 0.1Ω 2000Ω 1Ω 20kΩ 0.01kΩ 200kΩ 0.1kΩ 2000kΩ 1kΩ 9V 10mV 1.5V 10mV Resistance Battery Test Accuracy ±(0.
General Specifications Diode Test Continuity Check Batter Test current Input Impedance ACV Bandwidth DCA voltage drop NCV voltage range Display Overrange indication Polarity Measurement Rate Low Battery Indication Battery Fuses Operating Temperature Storage Temperature Operating Humidity Storage Humidity Operating Altitude Weight Size Safety Test current of 1mA max, open circuit voltage 2.8VDC typical. Audible signal will sound if the resistance is less than 30Ω 9V (6mA); 1.
