In the field of power system operation, maintenance and diagnosis, power transformers, as the core hubs of the power grid, are critical to the safe and stable operation of the entire network. Traditional testing methods often require multiple pieces of equipment, repeated wiring, and involve cumbersome procedures with low efficiency.
The launch of the KDZR‑ZR Transformer DC Winding Resistance & Transformation Ratio Integrated Tester adopts an integrated design that enables one‑time wiring and dual‑function testing, adapting to on‑site working conditions and becoming a widely used instrument for improving work efficiency and measurement accuracy.
The core value of this instrument lies in its integration of DC resistance testing and transformation ratio testing into one device. On‑site personnel only need to connect the wiring once to complete all test items sequentially, eliminating the trouble of switching equipment and repeated wiring. This not only significantly improves testing efficiency but also fundamentally reduces the risk of wiring errors caused by complex operations, making time‑critical tasks such as emergency repair and inspection more reliable and efficient.
The DC resistance testing function is intelligent and highly adaptable. The instrument can automatically recognize various winding connections, including Yn, Y, and △. It supports automatic three‑phase testing and calculates and displays the three‑phase unbalance rate in real time, providing intuitive evidence for quickly diagnosing hidden troubles such as winding inter‑turn short circuits and loose connections.Its output current ranges from ≤10 mA up to 20 A. The 20 A high‑current range is especially effective for measuring the very low resistance of low‑voltage windings in distribution transformers, ensuring accurate and reliable data.
The transformation ratio testing function is also comprehensive. It supports ratio measurement for three‑phase, single‑phase, and zig‑zag transformers, and is compatible with ratio and polarity tests for PT and CT.Its blind measurement function can automatically analyze and obtain results even when the winding connection group is unknown, improving flexibility when dealing with complex on‑site conditions.
The instrument’s reliability is supported by solid performance specifications.

• DC resistance measuring range: 0.5 mΩ – 50 kΩ, accuracy: ±(0.2% of reading + 2 digits)This wide range and high precision cover everything from large power transformers to small instrument transformers.
• Transformation ratio measuring range: 0.9 – 10000, accuracy: ±(0.1% of reading + 2 digits) in common rangesWith fine resolution, it ensures clear and precise measurement results.

Behind its performance is an innovative hardware‑software platform consisting of a dual‑core A7+M4 processor and an embedded Linux operating system.The A7 core ensures smooth and clear human‑machine interaction on the 7‑inch industrial touchscreen, while the M4 core focuses on real‑time and precise measurement control.This design achieves a balance between smooth operation and rigorous measurement. The Linux system provides a stable, secure foundation for stable operation and future function expansion.
To cope with diverse on‑site environments, the KDZR‑ZH features thoughtful design and expandability.It is equipped with a built‑in high‑capacity lithium battery and charging module, supporting direct AC220V charging for true mobile power supply, independent of on‑site power sources.Weighing approximately 6.5 kg, it has a compact and rugged structure, with an operating temperature range of ‑10 °C to 50 °C and strong humidity resistance, making it well‑suited for harsh outdoor conditions.