QuadTech Sentry 10 Plus, Instruction Manual

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Page 50 of 85 Operation
2.12 Instrument Offset
The Sentry Plus Series instrument provides automatic offset for lead and/or fixture effects.
During the offset process a correction is made (subtracted out) as the result of the measured
current with no DUT attached. For maximum measurement accuracy it is recommended that the
OFFSET function be performed on the Sentry Plus Series instrument after power up, any time
the test parameters are changed and any time the test leads or fixture is changed. Return and HV
test leads should not be connected together (open circuit) for AC and DC hipot tests. Return and
GC test leads should be connected (short circuit) for a GC test. There is no offset in an IR test.
Once the Offset function is turned ON for a specific program, it can be stored in memory with
that program. If the program parameters are changed the offset function will automatically turn
OFF and the offset function will be need to be performed again to get the new offset value. It
will then need to be restored in memory.
Prior to performing the OFFSET function:
•
Allow the instrument to warm up for 15 minutes.
•
Connect the Test cables (or fixture) to the OUTPUT and RTN/LOW connectors.
•
Program the test steps.
With the instrument in STAND BY status:
•
Press [F4] = MORE
•
Press [F3] = OFFSET
•
Follow instructions on display: i.e.: connect OPEN across OUTPUT terminal.
•
Press green [START] button.
•
Wait while instrument gets OFFSET value.
•
The OFST block at the bottom of the display is now highlighted (back lit).
•
Press [F4] = MORE to return to STAND BY status.
•
OR
To undo the OFFSET function:
•
Press [F3] = OFFSET
•
Follow prompt on display: “Turn off the offset function?”
•
Press [F3] = ENTER to turn off OFFSET function.
•
The OFST block at the bottom of the display is not highlighted now.
The following formulas apply to the offset function:
Measured Total Current Offset Total Current
100mA:
= -
2 2
Display Current Measured Total Current Offset Total Current - =
Display Current
For Offset Current > 100mA:
For Offset Current