Kaman SERIES 8000, Reference Manual

Page: 39 / 55

39
Calibration
The MCD-8000 calibration consists of a 2 point calibration that adjusts the offset and slope of
the resulting display. The scale factor of the MCD-8000 can be adjusted for a minimum of 200
microvolts per count (400 microvolts per count with +/-10VDC input option). In order to
calibrate the unit the following steps should be followed:
1) Select the input channel with the maximum voltage range to calibrate from. The
selector switch only changes the input. Once calibrated to a particular input the
remaining 5 channels will have the same calibration (you cannot have a different
calibration for each separate input). You must have the ability to change the
input to the meter so that you have the 2 data points near the extreme ends of
the input range.
2) Determine the display values for the 2 data points. You must insure that the
display has a minimum of 200 microvolts per count (400 microvolts per count
with +/-10VDC input option) or you will get an error when you try to calibrate.
To determine number of counts available for display divide the maximum voltage
input by 10000 (2000 for bipolar inputs). The decimal point location is
inconsequential for determining the display counts. Keep in mind that the
meter has four digits and ignore the decimal point location when determining
the number of counts. For example if you have a 0-.4 VDC sensor output you
can display .4VDC/.0002=2000 counts. If you are calibrating for English units
and .4VDC=40 mils and want to display the result in English units you would
probably not want to display the result in inches because the maximum the
display would show for the range would be .0040 so you would be losing
resolution. If you display the result in mils you may be tempted to try 40.00 but
this won't work because it requires 4000 counts and you can only use 2000
counts. This means that the best compromise is display in mils because you
can display 40.0 (losing the first digit this gives you 400 counts which is less
than the 2000 count maximum). If you must have more display resolution you
will need to increase the voltage output so that the minimum voltage/count
requirement is met. Don't forget, if you have a bipolar option the first digit gets
used by the sign so you only have +/-999 counts to work with.