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handheld meter

Handheld Milliohm Meter (Four Terminal Measurement)


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GAOTek Handheld AC Milliohm Meter with Four Terminal measurement is designed as low-resistance meter and a voltmeter with a wide resistance measurement range from 0.01 mΩ to 2 kΩ and is suitable for assembly line tests for all kinds of batteries. This meter comprises with m-Ohm and V mode that allows simultaneous measurement and comparison of battery internal resistance and open circuit voltage. It is equipped with Mini-USB RS232 interface which can be used for remote control, data acquisition and analysis. This meter adopts high performance 32-bit ARM processor.

Key Features

  • Four Terminal Method
  • Resistance measurement range from 0.01 mΩ to 2 kΩ
  • DC Voltage range from 1 V to 50 V
  • Maximum reading of resistance 2200 digits
  • Maximum reading of voltage 5000 digits
  • Built-in Mini-USB RS-232 interface
  • 5 in (89 mm) 16M color TFT-LCD screen
  • SCPI compatible command sets
  • Keypad lock Function
  • Data hold Function
  • Auto power off
  • 4 V Lithium 2200 mAh rechargeable battery
  • Customizable beep feature
  • Internal, External and Manual Trigger
  • Short-circuit clear zero for all ranges
  • ABS, PER and SEQ sorting methods
  • Range Auto, Manual and Nominal mode
  • Battery continuously works over 8 hours

Technical Specifications

Parameters AC resistance, DC voltage
Interface Built-in USB, Charging Interface, U disc Interface
Signal Source AC 1 kHz
Open Circuit Voltage 30 mv
Current 15 mA
Resistance Measurement Range 0.01 mΩ to 2 kΩ
DC Voltage Range 1 V to 50 V
Accuracy Resistance 0.5 %
Voltage 0.1 %
Maximum Display Digits Resistance 2200 digits
Voltage 5000 digit
Display Mode TFT- LCD Mode
Input 100 V to 240 V
Frequency 50 Hz/60 Hz
Output 9 V 1 A (DC)
Range 6 ranges with Auto, Manual and Nominal Modes
Trigger Mode Internal, Manual and BUS
Test Speed 20 times/second
Hold Mode Speed Range SLOW 2 times/second
MED 10 times/second
FAST 20 times/second
Auto Mode Speed Range SLOW 1.8 times/second
MED 6.8 times/second
FAST 16 times/second
SCPI Available
Baud Rate 115200 bps
Weight 22.3 oz. (650 g)
Dimensions 5.13 in x 8.3 in x 1.5 in (130.23 mm x 210.76 mm x 37.88 mm)
Accurate Temperature 73.4 ˚F ± 41 ˚F (23 ˚C ± 5 ˚C)
Accurate Humidity ≤ 65 % RH
Warming Timing >60 minutes
Adjustment Time 12 months
Nominal Humidity < 80 % RH
Working Humidity 10 % RH to 90 % RH
Storage Humidity 10 %  RH to 90 % RH
Nominal Temperature 59 ˚F to 95 ˚F (15 ˚C to 35 ˚C)
Operating Temperature 50 ˚F to 104 ˚F (10 ˚C to 40 ˚C)
Storage Temperature 32 ˚F to +122 ˚F (0 ˚C to 50 ˚C)


  • Internal resistance and voltage of the battery
  • Alkaline batteries, Life assessment lead batteries
  • UPS online measurement
  • Batteries identification test
  • Super capacitor ESR measurement
  • Contact resistance

Main Functions


Short-circuit clear zero correction for all ranges.

Comparator (Sorting Function):

 Set up the sorting function for GN/DG sorting

Comparator methods:

  • Absolute value of tolerance ± TOL sorting
  • Percentage tolerance %TOL sorting
  • Sequence comparison sorting

Beep Feature:

  • Beep: OFF/GD/NG
  • System Setup
  • Keypad lock function
  • Time and Date settings
  • Language switch option
  • Administrator account settings
  • Background brightness settings
  • Auto power off settings

Remote Control

Max baud rate: 115200 bps

SCPI available

ASCII transmit

Front Panel Summary:


  1. USB Host port
  2. Mini-USB Slave Port
  3. Reserved Interfaces
  4. Power Adaptor

Replace Battery

The instrument has built-in rechargeable battery, the battery has been installed in the battery compartment of the instrument. Replace the battery according to the following procedure.

Adjust Support

The support has two positions:

60 degrees and 45 degrees

45 degrees makes the instrument more stable

Power Supply:

The instrument can be powered by Li battery. When the battery is low, power adapter is used to charge the battery.

Charge the battery

Use the power adaptor to charge the battery. The Power key is orange when charging the battery even the instrument is turned off. When the battery is full the indicator is out.

Power key is orange when charging.

Turn ON/OFF:

To turn ON/OFF the instrument press the power key.

Test Slots:

Insert the cable box into test slots.

Clips and cables:

Using the clips and cables of other brands may cause damage and after 1 to 2 years the surface of the accessories may get damaged which will leads to inaccuracy.

<MEAS Display> Page

Press [Meas] key to enter <MEAS DISPLAY> page.

The <MEAS DISPLAY> page includes following step:

  • Trigger Mode [TRIGGER]
  • Measurement Range [RANGE]
  • Test Speed [SPEED]
  • Comparator [COMP] ON/OFF
  • [BEEP] Feature
  • Soft key VIEW DATA – To enter [VIEWDATA] page
  • Soft key SAVE DATA – To store Current Measurement Result into Internal Flash Disk


It includes three settings:

  • Internal Trigger
  • Manual Trigger
  • BUS Trigger

Trigger Setting:

Internal Internal trigger
Manual Press the [Enter] key once, the instrument runs a test cycle
BUS The instrument runs a test cycle by receiving RS232 trigger command.

Procedure to set the trigger:

Step 1 Press [Meas] key to enter <MEAS DISPLAY> page
Step 2 Use cursor keys to select [TRIGGER] field
Step 3 INT Automatic Internal trigger
MAN Manual trigger by pressing [Trig] key
BUS BUS trigger by RS232 SCPI command

Resistance [RANGE]

It has three range modes:

  • AUTO range
  • Manual range
  • Nominal range

Resistance Ranges:

Range Description Pros Cons
AUTO Automatically.

Impedance range is automatically set by selecting the best range

Convenient Test speed is slower than manual ranging
HOLD The instrument will always use the user-specified range Highest speed Set the range initially
NOMINAL Automatically

Select the best range according to nominal value

Best mode for sorting Only available in sorting mode

 Resistance Measurement Range:

Range Range Name Measurement Range
5 2 kΩ 200 Ω ~ 2.2 kΩ
4 200 Ω 20 Ω ~ 220 Ω
3 20 Ω 2 Ω ~ 22 Ω
2 2 Ω 200 mΩ ~ 2.2 Ω
1 200 mΩ 0 mΩ ~ 22 mΩ

Procedure of setting the range:

Procedure to set the trigger:

Step 1 Press [Meas] key to enter measurement page
Step 2 Use the cursor key to select [RANGE]
Step 3 AUTO Auto range
HOLD Current range is hold
NOMINAL Select the range according to resistance nominal value [ResNom]
INCR+ Increase range
DECL- Decline range

The DC voltage measurement range cannot be selected. Instrument always use automatic mode.

Test Speed:

SLOW, MED and FAST test speed can be selected.

Procedure to set test speed:

Step 1 Press [Meas] key to enter measurement range
Step 2 Use the cursor key to select [SPEED] field
Step 3 SLOW

Comparator [COMP]

Set the comparator parameter in <SETUP> page and the page is about how to turn on/off the comparator.

Step 1 Press [Setup] key to enter measurement range
Step 2 Use the cursor key to select [COMP] field
Step 3 OFF Comparator off
ON Comparator on

[BEEP] Feature:

Procedure to set the beep

Step 1 Press [Meas] key to enter measurement range
Step 2 Use the cursor key to select [SPEED] field
Step 3 OFF Turn beep off
GD Beep while pass
NG Beep while fail

Icons on <MEAS Display>

Icon Description
  Powered by Li battery
  Powered by external power supply
  USB-Disk is available
H Hold current data

< SETUP> page

Press [Setup] key to enter <SETUP>page.

In <SETUP> page, if the testing is not progress the Instrument does not display the measurement result and comparator result.

The <SETUP> page includes following setup:

  • Trigger Mode [TRIGGER]
  • Measurement Range [RANGE]
  • Test Speed [SPEED]
  • Comparator [COMP] ON/OFF
  • BEEP Feature
  • Soft key CLEAR ZERO – Clear Zero Correction
  • RESMODE – AC Resistance Sorting Methods
  • VOLTCOMP– DC Voltage Sorting Methods
  • ResNom – Input Resistance Nominal Value
  • ResLow – Input Resistance Low Limit
  • ResHigh – Input Resistance High Limit
  • VoltNom – Input Voltage Nominal Value
  • VoltLow – Input Voltage Low Limit
  • VoltHigh – Input Voltage High Limit

Some settings can be also set up in <MEAS DISPLAY> page.

Short-circuit Clear Zero [CLEAR ZERO]

Press [Setup] key to enter < SETUP> page, and then press [CLEAR ZERO] soft key to do short-circle clear zero. Once it’s done with short-circuit clear zero the value will be saved into internal flash disk.


It is necessary to do short-circle clear zero. When replace the test fixture or test cables, it is must to do short –circle clear zero.

Connect the test clip as shown in the below figure.

RS232 [BAUD] rate

Connect the instrument to computer via Mini-USB to RS232 port and the instrument will communicate with PC, meanwhile the keypad will be locked. Use the SCPI language in Mini-USB programming.

Mini-USB to RS232 format:

  • Data bits: 8
  • Stop bits: 1
  • Parity: none
Step 1 Press [SYSTEM] bottom soft key to enter <SYSTEM CONFIG> page
Step 2 Use the cursor key to select [BAUD] field
Step 3 1200 For the communication, converter opt with coupler isolation
115200 Best for communication with PC


Step 1 Press [Meas] or  <Setup> key to enter main page
Step 2 Press bottom soft key [SYSTEM] to enter <SYSTEM CONFIG>
Step 3 Press soft key [SYSTEM INFORMATION] to enter <SYSTEM INFORMATION> page

AC Resistance Range:

Range Max. Reading Resolution FAST MED SLOW Test Current
0 20 mΩ 22.00 mΩ 0.01 mΩ 0.8% ± 5 0.6% ± 3 0.5% ± 2 10 mA
1 200 mΩ 220.0 mΩ 0.1 mΩ 0.8% ± 4 0.6% ± 3 0.5% ± 2 1 mA
2 2 Ω 2.200 Ω 1 mΩ 0.8% ± 4 0.6% ± 3 0.5% ± 2 0.1 mA
3 20 Ω 22.00 Ω 10 mΩ 0.8% ± 4 0.6% ± 3 0.5% ± 2 10 µA
4 200 Ω 220.0 Ω 100 mΩ 0.8% ± 4 0.6% ± 3 0.5% ± 2 5 µA
5 2 kΩ 2.200 kΩ 1 Ω 0.8% ± 4 0.6% ± 3 0.5% ± 2 2 µA
Open-circuit Voltage: < 30 mVrms

 DC Voltage Range:

Range Max. Reading Resolution FAST MED SLOW
1 5.0000 V 5.0000 V 0.0002 V 0.5 % ± 4 0.5 % ± 2 0.1 % ± 5
2 50.000 V 50.000 V 0.002 V 0.5 % ± 4 0.5 % ± 3 0.1 % ± 5

Questions from our customers

  1. A

    The maximum display reading digits for resistance is 2200 digits and for voltage is 5000 digits.

  2. A

    This meter comes with a wide resistance measurement range from 0.01 mΩ to 2 kΩ.

Only registered users are eligible to enter questions