The instruments and equipment used for calibration must be calibrated by a metrological technical institution, meet the requirements for calibration
use, and be within the validity period.
The calibration equipment is mainly composed of: DC high voltage meter, DC high voltage power supply, standard plate electrode, distance regulator
and so on. The sensor is located on the center line of the calibration plate, and the block diagram of the non-contact electrostatic voltmeter calibration
device is as follows:
The equipment and device requirements are as follows:
C
——
calibrated product: electrostatic sensor;
D1
——
DC high voltage power supply: the output range is -20KV ~ +20KV, continuously adjustable, or the minimum step is 10V, and the
measurement uncertainty is less than 1/4 of the allowable error limit of the calibrated meter;
D2
——
DC high voltage meter: the measurement range is -40KV ~ +40KV, and the measurement uncertainty is less than 1/4 of the allowable error
limit of the calibrated meter;
D3
——
Standard plate electrode: the plate electrode should be round or square with rounded corners, and the radius of curvature of the electrode edge
should not cause corona phenomenon; the area of the plate should be large enough, and the diameter or side length should not be less than 0.4m. The
size of our calibration plate is 600mm*600mm square stainless steel plate.
R
——
Protection resistance: The withstand voltage of the resistance should be > 20KV, the current passing through the protection resistance and the
human body should be < 5mA, and the resistance value should meet the requirements of the following formula:
In the formula: R is the protection resistance, the unit is ohm (Ω);
R
d
is the resistance of the insulating support, the unit is ohm (Ω), the resistance value is > 1013Ω, and the withstand voltage is > 25KV.
The different resistance values of the above two resistors may result in different static voltage values detected under the same standard voltage
S1——Insulation bracket.
S2——Scale, measuring range: 0mm ~ 750mm, measurement uncertainty less than 0.5mm.
S3——Distance regulator: The sensor is placed on the calibration device with the front end of the sensor extending. The geometry and material of the
bracket should minimize the effect on the electric field distribution around the front end of the sensor.
R/(R+R
d
)
＜
0.1
％
Calibration environmental conditions
Calibration equipment
The calibration environmental conditions and requirements are as follows:
NO.
Contents
Model and parameters
1
High voltage
power supply
BERTAN_205B-20R
2
Plate
Material: stainless steel, thickness: 1mm, length and width: 600mm*600mm
3
Environment
Dust-free room, temperature: 20°C—23°C, humidity: 40
﹪
RH—45
﹪
RH, there
is no measurable electric field, magnetic field, positive and negative ions around
4
Device
The same standard device on both sides; ground wire, and theground wire
resistance is less than 1Ω
KV
Rd
D1
D2
D3
S1
C
S2
S3
S2
S3
KV
R
Rd
D1
D2
D3
S1
Vertical test
horizontal test
C
Product calibration
...
