Model: LC5296-AT /LC5248E-AT/LC5296V-AT
masibus
Doc. Ref. no. : - m61C/om/301
Issue no. 13
User’s Manual
Page 36 of 44
9. CALIBRATION PROCEDURE
9.1 Procedure for CAL-zero and CAL-span
The instrument is factory calibrated for the specified range, but due to long term drift of
components, re-calibration may be necessary in some cases. For calibrating the
instrument a reliable source is required. This source should be at least ten times
accurate compared to the range of the instrument.
The unit can be calibrated without opening it and without trim pots.
For Entering into the Calibration Mode, Please refer Menu Layout.
After applying appropriate Input from the calibrator source, press ‘INCREMENT’ OR
‘DECREMENT KEY’ to bring the actual process value on display.
Example:-
At zero calibration reading expected on the display is 100 and it shows 107, adjust the
process value to 100 by using
‘DECREMENT KEY’. Now press ‘SET’ to store the calibration
parameter in non-volatile memory. Similarly one can calibrate Ambient, SPAN and
retransmission parameters.
For calibrating i/p, both zero and span are calibrated. Here one-shot calibration
technique is used, i.e. the zero and span are calibrated once. Individual zero or span can
also be calibrated; first calibrate zero and then span. While calibrating thermocouple
type input, first calibrate the ambient (if required) and then continue with the span
calibration of the same.
9.2 Procedure for RET-zero and RET-span
For calibrating the retransmission output, both retransmission zero and retransmission
span has to be calibrated. At a time there can be either one or two retransmission output
available. If only one retransmission is used, then calibrate RTZ1 (retransmission 1
zero) and RTS1 (retransmission 1 span)and if there are two retransmission outputs
available, then calibrate RTZ2 (retransmission 2 zero)and RTS2 (retransmission 2 span)
for second retransmission. No need to feed input while calibrating retransmission o/p.it
is like calibrating using digital trim pot. Only look at the output, display value has no
significance with output generated.
Example:-
At retransmission zero calibration, expected output is 4.00mA and it gives 4.153mA.
Then adjust the output value to 4.153
by using ‘
IN
CREMENT KEY’. Now press ‘SET1’ to
store the calibration parameter in non-volatile memory. Similarly one can calibrate
retransmission span.
