Emerson 644 manual Calpointlo + Calminspan

Rosemount 644

Reference Manual

00809-0400-4728, Rev AA June 2011

Sensor Transducer Block Sensor Calibration, Lower and Upper Trim Methods

In order to calibrate the transmitter, run the Lower and Upper Trim Methods. If your system does not support methods, manually configure the Transducer Block parameters listed below.

1.Set MODE_BLK.TARGET to OOS.

2.Set SENSOR_CAL_METHOD to User Trim.

3.Set CAL_UNIT to supported engineering units in the Transducer Block.

4.Apply temperature that corresponds to the lower calibration point and allow the temperature to stabilize. The temperature must be between the range limits defined in PRIMRY_VALUE_RANGE.

5.Set values of CAL_POINT_LO to correspond to the temperature applied by the sensor.

6.Apply temperature, temperature corresponding to the upper calibration.

7.Allow temperature to stabilize.

8.Set CAL_POINT_HI.

NOTE

CAL_POINT_HI must be within PRIMARY_VALUE_RANGE and greater than

CAL_POINT_LO + CAL_MIN_SPAN

9.Set SENSOR_CAL_DATE to the current date.

10.Set SENSOR_CAL_WHO to the person responsible for the calibration.

11.Set SENSOR _CAL_LOC to the calibration location.

12.Set MODE_BLK.TARGET to AUTO.

NOTE

If trim fails, the transmitter will automatically revert to factory trim.

Excessive correction or sensor failure could cause device status to read “calibration error.” To clear this, trim the transmitter.

3-18