1. Power Supply
The DC resistance tester provides two types of power for testing: AC220V/DC12V. In the presence of strong electromagnetic interference, it is recommended to use DC power for testing, as the readings are stable and the anti-power frequency interference capability is strong.
A. DC Resistance Tester AC Power Supply Test:
Connect the AC220V power supply, the corresponding indicator light will turn on. Close the main power switch, the corresponding indicator light will turn on. Press the "Start/Stop" button to begin testing. After testing, turn off the main power switch (AC220V), the corresponding indicator light will turn off. After discharging, switch the test clips and proceed with the next test.
B. Charging:
Connect the AC220V power supply, the charging indicator light will turn on, indicating that the internal rechargeable battery is being charged. When the instrument is used with AC power for testing, it also charges the internal battery simultaneously. (The instrument is designed with a charging protection circuit to prevent overcharging.)
C. DC Power Supply Test:
Close the main power switch (DC12V), the corresponding indicator light will turn on. Close the main power switch, the corresponding indicator light will turn on. Press the "Start/Stop" button to begin testing. After testing, turn off the main power switch (DC12V), the corresponding indicator light will turn off. After discharging, switch the test clips and proceed with the next test.
2. Connection Method of Test Leads
Connect the I+, V+, V-, I- terminals of the instrument to the test object as shown in Figure 1.
Connect them properly. This connection method eliminates the contact resistance at points A, B, C, and D, as well as the influence of lead resistance on the measurement. The measured value is the resistance Rx between B and C (Note: Do not reverse the connections between B and C).
In use, if the test leads provided with the instrument are not long enough, you can extend them with wires of appropriate diameter.
3. Discharge
After testing, you can directly turn off the main power. If testing inductive samples, do not disconnect the leads immediately after turning off the power; allow the instrument to continue discharging. Generally, discharge for at least 20 seconds; otherwise, the back electromotive force of the inductor may endanger personal safety.
4. Measurement
When the DC resistance tester is powered on without the circuit properly connected, the display shows "E0000". Select the desired resistance range based on the value to be measured, press the corresponding range switch, and the indicator light for that range will turn on. The four-and-a-half-digit LCD will display the stable value, which is the measured resistance. Pay attention to the unit on the selected range when reading the value. When measuring large inductive samples such as power transformers, it is best to short-circuit other coils not involved in the test loop to avoid electromagnetic interference.
Main Features of DC Resistance Tester
1. Adopts high-speed 16-bit A/D converter, providing stable measurement data and good repeatability.
2. Automatic programmable current source technology, with a total of 1000 current ranges, automatically controlled by the internal microcontroller based on the measured resistance, achieving a wide measurement range and optimal measurement state without manual current range switching.
3. Fast response speed; the tap changer can be switched directly during measurement, and the instrument will automatically prompt, with the new resistance value displayed quickly.
4. Highly intelligent design with clever and advanced function settings, capable of automatically detecting faults such as loose test leads or broken wires.
