Calibration Procedure for Pressure Transmitters

DCR No.: 03009
Revision No.: 0

Effective: 7-21-03
Supersedes: 7-21-03
Revision Date: 7-21-03
Page No.: 1 of 3

1

Purpose

1.1 The purpose is to provide guidelines for field calibration on instruments after their installation.

2 Scope

2.1 This procedure shall cover all pressure transmitters that will be commissioned by Therma’s Calibration Department.

3 Reference

3.1 Manufacturer’s manual for the specific instrument.

4 Responsibility

4.1 Field calibration technician shall perform calibration as per the following procedures.

5 Procedures

5.1 Gather all necessary fittings and test equipment needed for specific transmitter. Make sure that the test equipment has been calibrated and within the calibration period.

5.2 Obtain manufacturer manual for any additional setup information.

5.3 Connect transmitter to pressure source test equipment and connect a milliamp meter in series with output of transmitter.

5.4 If necessary, verify the operation of the existing instrument and record in the "as-found" section.

5.5 Set the pressure source to the three points for calibration adjustments and record readings on a pressure transmitter calibration sheet, FN 6.017.1.

5.5.1 Set the pressure source to the low point of the transmitter range.

5.5.2 Allow readings to stabilize and adjust the zero potentiometer until the appropriate reading is achieved on the current meter.

5.5.3 Set the pressure source to the high point of the transmitter range.

5.5.4 Allow readings to stabilize and adjust the Span potentiometer until the appropriate reading is achieved on the current meter.

5.5.5 Set the pressure source to mid point of the transmitter range.

5.5.6 Allow readings to stabilize and adjust the Span potentiometer until the appropriate reading is achieved on the current meter.

5.5.7 Repeat the calibration adjustments as described in Steps 5.5.1 to 5.5.6 until readings are at appropriate levels.

5.5.8 Record all data on the pressure transmitter calibration sheet, FN 6.017.1.

5.6 Place Therma’s calibration sticker on the transmitter upon completion of calibration.

5.7 If the transmitter did not meet the calibration tolerances and adjustments, contact the customer.

6 Review and Approval

6.1 The field calibration technician shall submit the pressure transmitter calibration sheet, FN 6.017.1 to project manager.

Document Approval

Robert McCam
Quality Assurance Manager
7-21-03
Date