During inspections of switchgear, GIS, and transformers, partial discharge detectors need to balance portability and anti-interference capability. Compared with fixed online monitoring systems, handheld instruments rely more on battery management and sensor calibration; compared with single ultrasonic method devices, multi-signal fusion solutions can reduce misjudgment. The PDM-9200 uses a 32-bit ARM microprocessor, has a built-in large-capacity lithium battery, supports a 3.5-inch true-color LCD screen for reading data, can store 500 sets of measurement records, and supports one-key saving.
The detection sensitivity of the pulse current method can reach 0.02pC–0.1pC, while UHF/TEV/HFCT can reach ≤0.5pC–≤1pC under laboratory conditions. The maximum sampling rate is 2GS/s, with common rates of 100MS/s–200MS/s; sampling accuracy can be selected as 8-bit, 12-bit, 14-bit, or 16-bit. The testable sample capacitance is 6pF–250μF. The low end of the amplifier frequency band can be selected as 10kHz/20kHz/40kHz, and the high end can be selected as 100kHz/200kHz/300kHz. Positioning accuracy uses acoustic imaging or UHF/AE fusion positioning, reaching less than 1cm to ≤1m. Compared with devices that support only a single frequency band, this instrument is compatible with more test samples.
Technical engineers need to regularly check sensor connectors and cable shielding layers to avoid introducing interference due to poor contact. After each use, the probe should be cleaned and stored in a dry environment. When the battery is not used for a long time, it is recommended to charge it once every three months. Before on-site measurement, first confirm that the grounding is reliable, then turn on the instrument. Data storage and report generation support on-site printing and USB flash drive export, and can also upload to a computer via USB/Bluetooth to generate professional reports.
It is suitable for quantitative insulation condition testing and defect location of substation GIS combined electrical apparatus, switchgear, power cables, and transformers. By capturing signals such as electromagnetic waves, ultrasonic waves, and transient voltages generated by discharge, it assists in judging the trend of insulation deterioration. Compared with offline withstand voltage tests, partial discharge detection can be carried out under operating conditions, reducing power outage time.
