Tenmars TM-508A Battery Powered Milli-Ohmmeter


Tenmars TM-508A Milli-Ohmmeter Features:

  • 3-1/2 digit LCD display with maximum reading of 2000.
  • Battery powered with Low battery indication.
  • Zero adjustment: External zero adjustment control.
  • Very low impedance measurement, four-wire type, one pair insulated clip.
  • Wide measurement range 1 milliohm to 20k Ohm in six switchable steps.
  • Fuse protection: 2 Amp/250Volt (5mm x 20mm), fast minimum interrupt ratings 1500A.
  • Function keys: D-H switch lockup readings for LCD display.
  • Dimensions: 160mm (L) x 100mm (W) x 52mm (D)
  • Weight: 700g approx.

Authorised Australian Distributor


    Tenmars TM-508A User Manual

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SKU: TENMARS TM-508A Categories: , Tags: ,

The Tenmars TM-508A Battery Powered Milli-Ohmmeter offers very low impedance measurement by the Four Wire method (one pair of testing clips supplied).

Tenmars TM-508A applications include measurement of resistance in motor coils, transformers and printed circuit boards, plus the measurement of conductor, light electricity and welding point. The instrument’s wide measurement range is from 0.1mΩ to 20kΩ in 6 positions.

Tenmars TM-508A Battery Powered Milli-Ohmmeter Specifications:

Measuring Ranges Accuracy Resolution Test Current Open-Terminal Voltage
200 milliohms ±(0.3% of rdg + 1dgt) 0.1 milliohm 100mA 1.0 Volt maximum
2 ohms 1 milliohm 10mA
20 ohms 10 milliohms 10mA
200 ohms 0.1 ohm 1mA
2k ohms 1 ohm 1mA
20 kohms 10 ohms 100µA

Tenmars TM-508A Battery Replacement

The meter is powered by 1.5V battery x6pcs (NEDA 15F IEC R6 JIS UM-3). Use the following procedure to replace the battery:

1. Replace battery immediately when LCD displays “ ”.

2. Turn the function switch to the “OFF” position.

3. Use a screwdriver to unfasten the screws on the battery cover and remove the cover.

4. Take out the old batteries and replace with new batteries, taking care to note the correct polarity.

5. Re-install the battery cover and tighten the holding screws.

Replacement of fuse

For a safety protection of the electrical circuit please replace new fuse complying the specification 0.5A/250V, 5Øx 20mm. FAST MIN INTERRUPT RATINGS 1500A.

1. Select the function range switch to “OFF” position. To unscrew the bottom case by using a screwdriver.

2. Pull out the burned fuse and replace a new one.

3. Close the bottom case and tighten screw.

Maintenance and Care

1. That all necessary requirements of inspection and maintenance are not mentioned in this manual, a qualified technician should perform it.

2. This meter is a precision digital instrument, whether in use or in storage, please do not exceed the specification requirements to avoid any possible damage or danger during use.

3. Do not use strong or abrasive detergents, water and wet cloth to clean the instrument. Do use a dry cloth to clean the instrument.

4. Do not place this meter in high temperature or humidity or expose to direct sunlight.

5. Once the measurement is completed, turn the rotary switch to OFF, Remove the batteries from battery holder if the instrument is not is used for a long period in order to avoid the liquid leakage from the battery.

Weight 1 kg


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