Calibration Procedure - TTI QPX1200 Service Manual

The QPX1200 calibration menu can be found under extra functions "#99". The output calibrations
are dependent on the measurement being in calibration so it is recommended that each of the
calibrations be done in the order they appear on the menu.
Equipment Required
Voltmeter capable of reading up to 65 Volts with 1mV accuracy and up to 15V with 100µV accuracy,
a Current measurement system capable of measuring 60 Amps with 10mA accuracy, and resistance
less than 100mΩ (e.g. a 4-terminal shunt).
Procedure
01: Vout measurement calibration
Ensure that there is no load connected to the unit and connect the voltmeter directly across the front
panel output terminals. Select option 1 from the Calibration menu (Vout measurement) and press
OK. The unit now gives an output of about 1 Volt; measure it, enter the actual voltage (to the
nearest mV) and press OK. After a few seconds the output changes to about 50 Volts; measure and
enter this to the nearest mV, press OK. After a few seconds the display changes to the Calibration
menu again; output voltage measurement is now calibrated.
02: Vout setting calibration
Ensure there is no load connected to the unit. Select option 2 from the Calibration menu (Vout
setting) and press OK. The unit self-calibrates; during this time the output voltage will be switching
between different levels. After a few seconds the display changes to the Calibration menu again;
output voltage setting is now calibrated.
03: Iout measurement calibration
Connect the current measurement system directly across the front panel terminals. Select option 3
from the Calibration menu (Iout measurement) and press OK. The unit now gives an output of
about 1 Amp; measure it accurately, enter the actual current to the nearest mA, and press OK. After
a few seconds the output changes to about 50 Amps; measure and enter this to the nearest mA and
press OK. After a few seconds the display changes to the Calibration menu; output current
measurement is now calibrated.
04: Iout setting calibration
Connect the current measurement system directly across the front panel terminals or alternatively
connect a direct short-circuit. Select option 4 from the Calibration menu (Iout setting). The unit self-
calibrates; during this time the output current will be switching between different levels. After a few
seconds the display changes to the Calibration menu; output current setting is now calibrated.
05: Vmon measurement calibration
On the rear panel terminals short 'Vmonitor' to 'Vcontrol'. Ensure that there is no load connected to
the unit and connect the voltmeter from 'Vmonitor' to 'Common'. Select option 5 from the
Calibration menu (Vmon measurement) and press OK. The unit now gives an output of about 1
Volt; measure the voltage at 'Vmonitor' and enter the output voltage this represents (e.g. 6 times the
voltage measured for the 0V to 10V range) to the nearest mV and press OK. After a few seconds
the output changes to about 50 Volts; measure and enter the voltage represented by the voltage at
'Vmonitor' to the nearest mV and press OK. After a few seconds the display changes to the
Calibration menu; output voltage control is now calibrated.
06: Vmon setting calibration
On the rear panel terminals short 'Vmonitor' to 'Vcontrol'. Ensure there is no load connected.
Select option 6 from the calibration menu (Vmon setting) and press OK. The unit self-calibrates;
during this time the output voltage will be switching between different levels. After a few seconds
the display changes to the Calibration menu; output voltage monitor is now calibrated.

Calibration Procedure

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