Page 36 · 685 Series
ComboPak
User’s Manua
l
The
ComboPak
is typically calibrated annually. Calibration can be done one of
two ways: the instrument can be returned to the factory for a full recalibration, or
the user calibration commands can be used for simple slope/offset calibration.
Factory calibration has the benefit of a full multi-point calibration and verification
of instrument performance against NIST-traceable instrumentation, using
equipment and test loads designed specifically for the application.
However, field (or user) calibration is possible, and often desirable, as it allows
the user to meet certification or calibration requirements not available through a
factory calibration.
This field or user calibration is accessible through the
LASER:USERCAL
and
TEC:USERCAL
commands over the computer interface.
Basic steps for user calibration:
1.
Take measurements to generate slope and offset values for elements
you wish to calibrate.
2.
Enable user calibration editing using the TEC:USERCAL:EDIT or
LASER:USERCAL:EDIT command.
3.
Update the user calibration data using the TEC:USERCAL:PUT or
LASER:USERCAL:PUT command.
The above is a very abbreviated list of commands. See the LASER:USERCAL
and TEC:USERCAL commands in the
Computer Interfacing Manual
for more
detail.
For each set point or measurement, there is a corresponding slope and offset
calibration. For example, the
ComboPak
laser current uses the “high”
calibration range (index 2 for set point, and index 7 for measurement)
–
see the
TEC:USERCAL:PUT or LASER:USERCAL:PUT commands for a complete list of
indexes.
When the slope is 1 and the offset is zero, this is considered an
“uncompensated” measurement. If you change either the slope or offset, the
CAUTION
Because user calibration directly affects the
performance of the instrument, it must be performed by
a qualified technician with sufficiently accurate meters
and test loads to properly measure the actual
performance of the instrument. Failure to do so could
significantly degrade the performance of the instrument
or damage your device.
