INSTRUCTION MANUAL DM391/393 1-800-547-5740 • Fax: (503) 643-6322 www.ueitest.com • email: info@ueitest.
Introduction The DM391/393 are some of our safest industrial duty meters ever made. All inputs, ranges and functions protected to 1000 Volts CAT III. Perfect for HVAC and electrical technicians whose applications require higher accuracy measurements and True RMS precision. Built in temperature means one less instrument to bring to the job. The DM393 has convenient access to battery and fuses without breaking ca l i b ration seals.
6. Common Input Terminal (ground reference): All measurement functions. µA: Micro-amps AC rms and micro-amps DC measurements (DM393) Micro-amps AC and milli-amps DC measurements (DM391) mA: Milli-amps AC rms and milli-amps DC measurements (DM393) Milli-amps AC and milli-amps DC measurements (DM391) A: Amperes AC rms and amperes DC measurements (DM393) Amperes AC and amperes DC measurements (DM391) 7. Input Terminal for All Functions: Except current (A, mA, µA).
Operating Instructions Voltage (V or V, V) Measurements Voltage is the difference in electrical potential between two points. The p o l a r i tyof AC (alternating current) voltage varies over time, while the p o l a r i tyof DC (direct current) voltage is constant over time. V function defaults at DC. Press the “SELECT” push-button momentarily to select AC.
Diode ( ) Test CAUTION! Discharge all high-voltage capacitors before testing diodes. Large value capacitors should be discharged through an appropriate resistance load. Use the diode test to check diodes, transistors, silicon controlled rectifiers ( S CRs), and other semiconductor devices. The test sends a current through a semiconductor junction, then measures the junction’s voltage drop.
Tips for Measuring Capacitance Current (µA, mA, 10A) Measurement • In capacitance, the meter is always autoranging • In 40nF range, the readings are probably unstable due to environmentally induced electrical noise and floating capacity of the test leads. Therefore, directly connect the object to be measured to the input terminals. Use “REL∆” in this range for accurate measurement - The meter will display 0.
Tips for Measuring Current • When measuring a 3-phase system, special attention should be taken to the phase to phase voltage which is significantly higher than the phase to earth voltage. To avoid exceeding the voltage rating of the protection fuse(s) accidentally, always consider the phase to phase voltage as the working voltage for the protection fuse(s). • When measuring current, the meter’s internal shunt resistors develop a voltage across the meter’s terminals called “burden voltage”.
Specifications Backlight Fast autoranging Safety and Compliance Maximum voltage between any terminal and the ground Compliances Certifications Surge protection Fuse protection fro mA or µA inputs Fuse protection for A input Operating temperature Storage temperature Temperature coefficient Relative humidity Altitude Complies with CSA C22.2 No 1010.1-92, NASI/ISA-S82, 01-94 to 1000 V overvoltage category III UL & cUL standard UL 3111-1 listed CE-marking certified 8kV peak per IEC 1010.
DC Current Range Frequency and Duty Cycle Resolution Accuracy DM391 400µA 4000µA 40mA 400mA 4A 10A 0.1µA 1µA 10µA 100µA 1mA 10mA 1.0% + 2 1.0% + 2 1.5% + 5 1.5% + 5 AC Current Range Resolution Accuracy 40 Hz - 400 Hz DM391 DM393 400µA 4000µA 40mA 400mA 4A 10A 0.1µA 1µA 10µA 100µA 1mA 10mA 400Ω 4000Ω 40kΩ 400kΩ 4MΩ 10MΩ 1.0% + 5 1.0% + 5 1.5% + 10 1.5% + 10 1.5% + 5 2.0% + 10 Resolution 0.001Hz 0.01Hz 0.1Hz 1Hz 10Hz 100Hz 1kHz 10kHz 0.1% DM393 1.
Glossary of Terms Average sensing RMS calibrated: RMS (Root-Mean-Square) is the term used to describe the effective or equivalent DC value of an AC signal. most digital multimeters use average sensing RMS calibrated technique to measure RMS values of AC signals. This technique is to obtain the average value by rectifying and filtering the AC signal. The average value is ten scaled upward (that is, calibrated) to read the RMS value of a sine wave. in measuring pure sinusoidal waveform.
DM391/393 Digital Multimeter Limited Warranty The DM391/393 is warranted to be free from defects in materials and workmanship for a period of five years from the date of purchase. If within the warra n ty period your instrument should become inoperative from such defects, the unit will be repaired or replaced at UEi’s option.
