Transformer DC Resistance Tester

The DC resistance tester (micro-ohmmeter) is a high-precision replacement product that supersedes the traditional DC single and double-arm bridges. The fast DC resistance tester utilizes switching power supply technology and displays measurement results via a dot-matrix LCD screen. It overcomes the drawback of other similar products where LED display values are difficult to read in sunlight, while also featuring an automatic arc suppression function.

DC resistance testing is an essential procedure for transformers after handover, major overhauls, or tap changer adjustments. Traditionally, measuring the DC resistance of transformer windings and high-power inductive equipment using conventional methods (bridge method and voltage drop method) is time-consuming and labor-intensive. To address this, the fast DC resistance tester was developed to reduce measurement time and alleviate the workload of testing personnel. With a high-speed microcontroller at its core, built-in rechargeable batteries and charging circuits, high-speed A/D conversion, and programmable current source technology, it achieves efficient measurement and highly automated functions. It offers high precision, wide measurement range, stable data, excellent repeatability, strong anti-interference capability, and comprehensive protection features. Compact, lightweight, and portable, it provides rapid measurement, ease of use, high accuracy, and fast charging and discharging. Self-check and automatic calibration functions reduce the difficulty of instrument use and maintenance, making it an ideal device for measuring the DC resistance of transformer windings and high-power inductive equipment.

The DC resistance tester is a next-generation instrument for testing transformer DC resistance. It automatically selects the test current based on different types of power transformers and displays results quickly. It also includes functions such as storage, printing, and discharge indication. Equipped with non-volatile memory, it can store measurement data long-term. The use of an LCD screen ensures a user-friendly interface, making it a common device in DC resistance testing.

The DC resistance tester is a high-precision, wide-range resistance tester controlled by a high-performance microprocessor. It can measure resistances from 1μΩ to 3MΩ, displaying up to 30,000 counts. With a testing speed of 60 times per second, it maintains an accuracy of 0.05% even at 15 times per second, and reading fluctuations are controlled within 3 digits. Standard temperature compensation allows for resistance testing under various conditions. Three current modes meet demanding resistance testing requirements. Designed for measuring the DC resistance of large-capacity transformers, it integrates a high-precision constant current source and testing components. The testing process is microcomputer-controlled, automatically completing constant current judgment, data acquisition, data processing, resistance display, and printing.

The DC resistance tester is a high-precision upgrade replacing DC single and double-arm bridges. Utilizing switching power supply technology, it measures over a hundred times faster than bridges. The display section uses a four-and-a-half-digit LCD for measurement results and a three-and-a-half-digit LCD for ambient temperature or test current values, overcoming the sunlight readability issue of LED displays in other products. It also includes an automatic arc suppression function. The instrument offers fast measurement, high precision, intuitive display, strong anti-interference capability, compact size, low power consumption, stable and reliable test data, and immunity to human factors. It comes with built-in rechargeable battery packs (12V) and supports both AC and DC power, making it suitable for on-site and field testing.