I.OVERVIEW

Huazheng Electric Insulation Oil Dissipation Factor and Resistivity Measuring System DTL, is designed and manufactured based on GB/T5654-2007 of《Liquid insulating material of relative permittivity, dielectric loss factor and DC resistivity measurements》. It is used for measuring dielectric dissipation factor and DC resistivity of insulating oil and other insulating liquids. The instrument is characterized by integrated structure, and integrates test cell, temperature controller, temperature sensor, dielectric loss test bridge, AC test power, standard capacitor, high resistance meter, DC high voltage source and other major components. The instrument adopts full digital technology and all of the intelligent automatic measurement, is equipped with large colcor screen (800*480) LCD display, which each step has prompted the Chinese, the test results can be automatically stored and printed output, so that the operator without professional training will be able to use it proficiently.

II.The main functions and features

1. The test cell used of the three-electrode structure in line with the national standard GB/T5654-2007, with electrode spacing 2mm, can eliminate the effects of the stray capacitance and leakage on dielectric loss test results. The apparatus is equipped with the oil drainage solenoid switch, and we can empty the test cell in case of not removing it and rinse it with the test sample.

2. The instrument adopts the medium frequency induction heating, PID temperature control algorithm. This heating method has the advantages of t non-contact between the test cell and the heating body, even heating, fast speed, convenient control, strict control of the temperature within error range of the preset temperature.

3. Internal standard capacitor is SF6 gas-filled three-electrode capacitance, and its capacitor dielectric loss and electrical capacity is independent of ambient temperature, humidity and other effects, so that the instrument accuracy can be ensured even after prolonged use.

4. AC test power supply using AC-DC-AC conversion, effectively avoid the fluctuations in mains voltage and frequency on dielectric loss measurement accuracy effect. Even a generator, the instrument can work properly.

5. Perfect protection function; When there is over voltage、over current or high-voltage short circuit, instruments can quickly cut off pressure, and issues a warning message. When the temperature of the sensor failure or not connected, the instrument will also issue a warning message.

6. There is a temperature limiting relay in the medium frequency induction heating furnace. When temperature above 120 degrees, the instrument frees the relay and stops heating.

7. More convenient the experimental parameter is set. Temperature setting range 0～120℃, AC voltage setting range 500～2000V, DC voltage setting range 300V～500V.

8. Using of large-screen LCD display, with backlight and clear display. Friendly interface, simply follow the Chinese menu prompt, enter the command, the instrument can be automatically tested. And automatically store and print test results.

9. Built-in real-time clock, the test date and time may be saved, displayed and printed with the test results.

10. Calibration functions of cleaned dry cell. The measurement of dry cell’s capacitance and dielectric loss factor can determine its cleaning and assembly conditions. The calibration data is automatically saved and so that it facilitates the calculation of relative permittivity and DC resistivity.

III.MAJOR TECHNICAL INDICATORS

Voltage supply:  AC 220V±10%

Power frequency： 50Hz/60Hz ±1%

Measuring range：

Electric capacity   5pF～200pF

Relative Permittivity 1.000～30.000

Dielectric loss factor 0.00001～100

DC Resistivity  2.5MΩm～20TΩm

Measuring accuracy：

Electric capacity   ± (1% of measured value+0.5pF)

Relative Permittivity  ±1% of measured value

Dielectric dissipation factor ± (1% of measured value+0.0001)

DC Resistivity   ±10% of measured value

Resolution：

Electric capacity   0.01pF

Relative capacitivity  0.001

Dielectric dissipation factor 0.00001

Measured temperature range：0～120℃

Temperature measurement error：±0.5℃

Test Voltage AC(RMS)： 500～2000V Continuously adjustable, frequency 50Hz

Test Voltage DC： 300V～500V  Continuously adjustable

Power consumption：100W

External dimensions： 500×360×420

Total weight： 22Kg

IV.USE CONDITIONS

Ambient temperature：0℃～40℃

Relative humidity(RH)：<75%