1.?External hole type?current sensor with high precision is often used instead of the traditional sampling unit, which includes?more than one switch circuit. During testing, multiple short tabs are needed to lead end shielding current to test instrument. GDDJ - HVC?uses traditional straight-through?structure, can be installed near the equipment, lead of end shielding is not broken, and the length is very short, which avoid open circuit of end shielding. The sensor can accurately detect signals within 100μA~700mA. Impedance of sensor is low, can withstand power frequency current 10A and lightning impulse current 10kA, meet use conditions of online detection.

2.?The sampling unit adopts die-casting?aluminum shell sealing waterproof design, and adopts waterproof cable connector for secondary output, which is convenient for?connection; After the sensor is installed, it is normally?not energized. For testing, only the secondary cable of the sampling unit need?be connected, and "plug and play" can be achieved without any operation on the end shielding signal cable.

3.?The core processor of the?instrument?is American TI 32-bit floating-point high performance digital signal processor (DSP), which runs a?real-time operating system and adopts an extended 16-bit, high-speed, multi-channel synchronous sampling analog digital converter (A/D) to realize real-time measurement and high-precision calculation of the monitored quantity. Able?to monitor multiple devices simultaneously.

4.?Two on-line detection methods for dielectric loss can be provided, which can measure dielectric loss difference and capacitance ratio of two capacitive devices in the same phase, and PT secondary voltage can be used as the reference signal to measure the capacitance and dielectric loss of the device. Using the compensating current sensor and advanced digital filtering technology, the problem of dielectric loss precision and stability?is solved, combined with perfect electromagnetic shielding measures and advanced processing technology, digital filtering can ensure dielectric loss test results are not affected by the influence of harmonic interference and pulse interference, with absolute precision up to ±0.05%.

5.?With the detection?of dielectric loss difference and capacitance ratio of in-phase capacitive equipment, it?can not only avoid the distortion of dielectric loss test result caused by using PT secondary voltage as the reference signal, but also help to reduce the influence of phase-to-phase electric field interference.

6.?The detector is equipped with a large LCD screen for displaying the monitored voltage, current, dielectric loss, resistive current, capacitive current and other data.
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7.?The tester not only has the function of live detection, but also can monitor the equipment online for a long time, and automatically record the monitored data.

8.?The system adopts external sensors instead of "traditional sampling unit", which can be easily upgraded from "live detection" to "online monitoring" under normal operation of the equipment. There is no need to remove the installed sensors, no need to disable the device, just add a monitoring unit (IED).

9.?The detector adopts portable design, simple to operate, the lithium battery in the machine can maintain 8 hours of continuous working time, fully meet the requirements of field use.