Model: CDU-LCD
Doc. Ref. no.:- mMP/om/601
Issue no. 00.06
User’s Manual
Page 19 of 32
7. CALIBRATION PROCEDURE
7.1
Procedure for calibration zero and span
The instrument is factory calibrated for the specified range of Differential Pressure
input (PV), 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.
To calibrate Differential Pressure Sensor of CDU-LCD zero calibration, span point 1
calibration and span point 2 calibrations are required.
Zero calibration: The value should be calibrated to zero only.
Example:
if process value is 2, then calibrate that value to 0.
Span Point 1 Calibration: It can be done either at positive side or negative side.
Example:
0 to 120 Pascal. 0 means zero calibration and 120 means span point 1
calibration.
0 to -120 Pascal. 0 means zero calibration and -120 means span point 1
calibration.
Span Point 2 Calibration: It can be done at positive side only.
Example:
0 to 200 Pa. 0 means zero calibration and 200 means span point 2 calibration.
For Calibration, use utility software.
Apply appropriate Input from the source, and press buttons for
PRS Zero.
For span point -1 calibration, user can enter value or default point is also given set
appropriate source and press button
PRS Span Point
– 1.
