The power industry standard DL/T845.4-2004 is adopted, and it is designed by combining high-frequency switching power supply technology with digital circuit technology. It is suitable for
measuring the loop resistance of switch control equipment. The test current adopts the DC 100A recommended by the production standard. The loop resistance can be directly measured under DC 100A, and the test results are displayed on a large-screen LCD, with functions such as data storage, output printing, and time setting. There is also a 50A gear for users to choose. It is a special equipment for measuring the contact resistance and loop resistance of switch control equipment. The test current adopts the 100A DC recommended by the production standard GB763. This loop resistance tester can directly measure the loop resistance or contact resistance under 100A current and display it directly. It can also save the data to the instrument, with a total of 100 groups. The saved data can be uploaded to a computer via the RS232 interface. This switch loop resistance tester has accurate measurement and stable performance, and is suitable for on-site high-voltage switch maintenance in the power and power supply departments and the loop resistance test requirements of high-voltage switch factories.
Functional features of the switch contact resistance tester:
1. 320×240 LCD display, high-speed thermal printer.
2. This instrument has the characteristics of small size, light weight, strong anti-interference ability, high precision, convenient operation, and complete protection functions.
3. The latest power supply technology is adopted, which can continuously output large current for a long time, and flexibly select four current gears: 50A, 100A, 150A, and 200A.
4. A precision instrumentation operational amplifier and a high-precision quadruple-integral A/D converter are used, combined with a high-performance 16-bit single-chip microcomputer. During measurement, the system automatically switches the amplification factor according to the signal size, ensuring the test accuracy of this product.
5. This product is also designed with a real-time calendar clock, providing a time basis for printing and saving data.
6. Data storage and historical data browsing functions can store 200 groups of data and have power-off protection.
7. Ultra-wide range, the maximum measurement range reaches 0-4mΩ.
8. Human-machine dialogue full-keyboard operation mode, intelligent working process throughout.
Product features:
1. Large current: The new switching power supply technology is adopted, which can continuously output large current for a long time, overcoming the disadvantage of instantaneous current of pulse power supplies, effectively breaking through the oxide film of switch contacts, and achieving good test results.
2. High stability: Under severe interference conditions, the last digit of the LCD screen data can be stable within ±1 digit, with stable readings and good repeatability.
3. High precision: Dual-channel high-speed 16-bit Σ－Δ AD sampling and new digital signal processing technology are adopted, with a resolution of 0.01μΩ. It is currently the contact resistance tester that can achieve a resolution of 0.01μΩ and is very stable in China, with performance exceeding imported large-current micro-ohmmeters.
4. Intelligent: An imported high-performance CPU is used. During measurement, the system automatically switches the range according to the signal size, ensuring the test accuracy of this product. The over-temperature protection circuit can automatically stop outputting current when the instrument exceeds the set temperature, ensuring the safe use of the instrument.
5. High quality: All key components are imported, and the cleverly designed temperature compensation circuit effectively eliminates the influence of ambient temperature on measurement results. The use of connectors enhances vibration resistance.
6. Powerful functions: The current can be freely selected between 50A and 100A, and the test time can be set arbitrarily within 5s~599s, overcoming the defects of other similar instruments that cannot set the measurement time or have too short continuous working time, far exceeding the performance of other similar instruments.
7. Friendly human-machine interface: Data input through a rotary mouse is convenient and fast. The instrument date and time can be set independently, measurement data can be saved in real time, and measurement results can be printed immediately.
8. Multiple communication methods: It can communicate with a computer via RS232 serial port (9-pin) or USB data cable, uploading measurement data to the computer for further analysis and processing by test personnel.
9. Easy to use: Small size, light weight, and easy to carry.
