SOP for Calibration of Temperature Gauge

PURPOSE

To define the procedure for calibration of Temperature Gauge

SCOPE

Range -80 to 1100 °C at Lab

RESPONSIBILITY

Calibration Engineer

MASTER EAQUIPMENT USED

Standard PRT sensor, Digital Thermometer Readout (chub-4), Liquid Temperature Bath, Dry Block

ENVIROMENTAL CONDITION

Temperature - (25 ± 3)°C

Humidity - (50± 10) % RH

PROCEDURE

Temperature Gauge is visually checked for no any physical damage.
Temperature Gauge under calibration is attached an under calibration tag. The type, Range, S.No, Make & other details of the temperature gauge are recorded in observation Sheet.

Switch on the Liquid Temperature Bath OR Dry Block for the temperature source and set it at the desired range for the calibration Point of Temperature Gauge.
PRT and Temperature Gauge under calibration are put into the Liquid Temperature Bath.
Record Temperature during calibration in Observation Data Sheet.
Ensure all the connectivity of the reference sensor with digital thermometer readout is correct.
Allow sufficient time to stabilize of equilibrium temperature at the set value and ensure before taking the measurement of the PRT as well as the Temperature Gauge under calibration.
Wait for 15 to 20 minutes at the set temperature so that the dry block stabilizes at the set temperature.
On Stabilization, the set temperature of PRT &Temperature Gauge under calibration has recorded the temperature on the observation sheet.
Five measurements are observed and record the temperature for each calibration set point repeat the above step for other temperature set points and cover the range as per customer request.
After Calibration the Temperature Gauge is not to be removed immediately, allowing sufficient time to cool until the ambient temperature is reached.
Calculate the measurement uncertainty by taking 5 repeated readings at same Measurement point.
Affix the calibration sticker on the Temperature Gauge.
Prepare the Calibration certificate.