Smart Loop Resistance Tester
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The Smart Loop Resistance Tester is designed based on the latest power industry standard DL/T845.4-2004 of the People's Republic of China, combining high-frequency switching power supply technology with digital circuit technology..The Smart Loop Resistance Tester is suitable for measuring the loop resistance of switch control equipment. Its test current adopts the national standard recommended DC 100A and 200A. The loop resistance can be directly measured at currents of 100A and 200A, and the final test results are displayed on a large-screen LCD, with functions such as data storage, output printing, and time setting. Additionally, 50A and 150A gears are available for user selection. This instrument provides accurate measurement and stable performance, meeting the requirements for on-site high-voltage switch maintenance in power and power supply departments, as well as loop resistance testing in high-voltage switch factories.
Product Overview
When measuringthe contact resistance of the conductive circuit in high-voltage switches, due to the influence of oil film and oxide layer between contacts, the measured value is several times larger, failing to truly reflect the contact resistance value. Therefore, the Ministry of Electric Power standard SD301—88 "AC 500kV Power Equipment Handover and Preventive Test Procedures" and the new edition of "Preventive Test Procedures for Power Equipment" stipulate that the measurement current for contact resistance of circuit breakers and disconnectors shall not be less than DC 100A to ensure accurate test results.
Smart Loop Resistance Tester Currently, the conventional QJ44 double-arm DC bridge is commonly used in power systems to measure contact resistance, but the test current of such bridges is only at the mA level, making it difficult to detect defects such as reduced cross-sectional area of the circuit conductor. When measuring the contact resistance of high-voltage switch conductive circuits, due to the influence of oil film and oxide layer between contacts, the measured value is several times larger, failing to truly reflect the contact resistance value. Therefore, the Ministry of Electric Power standard SD301—88 "AC 500kV Power Equipment Handover and Preventive Test Procedures" and the new edition of "Preventive Test Procedures for Power Equipment" stipulate that the measurement current for contact resistance of circuit breakers and disconnectors shall not be less than DC 100A to ensure accurate test results.
Equipment Usage
Smart Loop Resistance Testeris suitable for high-precision measurement of contact (loop) resistance in high-voltage switches, and is also applicable to other occasions requiring large current and micro-resistance measurement.
High Stability: Under severe interference conditions, the last digit of the LCD data can remain stable within ±1 digit, with stable readings and good repeatability.
High Precision: Using dual-channel high-speed 16-bit Σ－Δ AD sampling and the latest digital signal processing technology, the maximum resolution reaches 0.01μΩ, making it the only contact resistance tester in China that can achieve 0.01μΩ resolution with high stability, outperforming imported large-current micro-ohmmeters.
Intelligent: Using an imported high-performance CPU, the system automatically switches ranges based on signal strength during measurement, ensuring the accuracy of the product. The over-temperature protection circuit automatically stops output current when the instrument exceeds the set temperature, ensuring safe use.
High Quality: All key components are imported, and a cleverly designed temperature compensation circuit effectively eliminates the influence of ambient temperature on measurement results. The use of military-grade connectors enhances vibration resistance.
Powerful Functions: The current can be freely selected between 50A and 100A, and the test time can be set arbitrarily from 5s to 599s, overcoming the defects of other similar instruments that cannot set measurement time or have too short continuous working time, far exceeding the performance of other similar instruments.
Friendly Human-Machine Interface: Data input via a rotary mouse is convenient and fast, allowing users to set the instrument date and time, save measurement data in real-time, and print measurement results immediately.
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.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
