KEPCO BHK 1000-0.2MG, Руководство оператора

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BHK-MG (OPR) (OPR) 032816
4-1
SECTION 4 - CALIBRATION
4.1 GENERAL
This section contains the calibration instructions for the Power Supply. It is recommended that
the user be familiar with Local Mode operation (PAR.3.2) before calibrating the unit.
A full calibration consist of a voltage calibration and a current calibration. Both voltage and cur-
rent calibrations consist of a zero and a full scale calibration. Calibration of current requires full
scale calibration of both scales: High (Io
MAX
) and Low (Io
MAX
/10).
There are two ways to perform the calibration: locally using the front panel keys or remotely
sending commands through the GPIB bus. These two ways cannot be combined.
In order to enter the calibration mode the correct calibration access code (password) must be
entered. If the password has been forgotten, call the factory. During the calibration, new calibra-
tion data is computed which is then stored in the nonvolatile memory.
4.2 EQUIPMENT REQUIRED
The following equipment is required to calibrate the BHK-MG Power Supply.
• Digital Voltmeter (DVM) with 6 digits resolution an at least 0.002% accuracy for d-c mea-
surements.
• Precision Shunt Resistor (with a tolerance of 0.01%, power rating of at least 10 times
larger than the maximum stress, and a temperature coefficient equal to or better than 20
ppm per degree C). During the calibration procedure the LCD displays the minimum
requirements for the shunt resistor. However, to avoid problems due to drift caused by
heat dissipation, Kepco recommends the following:
– BHK 300-0.6MG: 1.67 Ohm, 0.01%, 50W
– BHK 500-0.4MG: 2.5 Ohm, 0.01%, 25W
– BHK 1000-0.2MG: 5 Ohm, 0.01%, 10W
– BHK 2000-0.1MG: 10 Ohm, 0.01%, 5W
NOTE: • Because the voltage measured will be used as reference for calibration, the DVM
used must be accurately calibrated prior to calibrating the BHK-MG power supply.
• Proper cooling of the external precision shunt resistor ensures the accuracy of the
calibration.
4.3 CALIBRATION PROCEDURES USING FRONT PANEL KEYPAD
During voltage calibration, the voltage, overvoltage and voltage readback are calibrated and
during current calibration the current, overcurrent and current readback are calibrated. The nor-
mal procedure is to calibrate voltage first and then current. However, you do not have to do a
complete calibration each time. If required, you may calibrate only the voltage or the current and
then proceed to saving the calibration results. For either voltage or current calibration, BOTH
zero AND full scale calibrations must be performed.
For both current and voltage calibration all loads must be disconnected from the power supply
output; the sense terminals must be connected to the corresponding output terminals. For volt-