J Thermocouple Calibration

J Thermocouple Calibration Procedure using a calibration voltage source

• Connect the calibration voltage source to the logger observing the correct polarity
• Set the calibration source to 0.0 mV
• Enter 0 in to the box labeled First Point Actual Value
• Note: If you are using °F enter 32 instead of 0
• Click the First Point Button
• Set the calibration source to 57.94 mV
• Enter 1000 in to the box labeled Second Point Actual Value
• Note: If you are using °F enter 1832 instead of 1000
• Click the Second Point Button
• The Calibration Offset and Calibration Gain figures will now be calculated and shown on the calibration screen.
• These Offset and Gain figures should now be written to the logger
• Click the Write Unit, Scaling and Calibration Values to logger button
• The Calibration process is now complete

To check the Calibration

• Go to the Realtime screen
• Set the calibration source to 0.0 mV
• The J Thermocouple gauge on the Realtime screen should show the ambient temperature (Ambient Temperature plus 0°C)
• Set the calibration source to 57.94 mV
• The J Thermocouple gauge on the Realtime screen should show Ambient Temperature plus 1000°C

This calibration procedure is based on the following data.

1. a J thermocouple junction gives 0.0mV when the thermocouple and the logger are at the same temperature.
2. It will give 57.94mV when there is a 1000degC difference between the logger and the thermocouple.

J Thermocouple Calibration Procedure °C using two known temperatures

• Connect the J thermocouple sensor to the logger
• Allow the J thermocouple sensor to stabilize at the first known (lower) temperature
• Read the Ambient Temperature of the Logger using the Realtime Screen
• Enter the first known temperature MINUS THE AMBIENT TEMPERATURE in to the box labeled First Point Actual Value
• Click the First Point Button
• Allow the J thermocouple sensor to stabilize at the second known temperature
• Read the Ambient Temperature of the Logger using the Realtime Screen
• Enter the second known temperature MINUS THE AMBIENT TEMPERATURE in to the box labeled Second Point Actual Value
• Click the Second Point Button
• The Calibration Offset and Calibration Gain figures will now be calculated and shown on the calibration screen.
• These Offset and Gain figures should now be written to the logger
• Click the Write Unit, Scaling and Calibration Values to logger button
• The Calibration process is now complete

If this procedure is used the J Thermocouple will show the correct temperature when sitting in free air.

If the ambient temperature is not subtracted from the known temperatures the J thermocouple will read high by the amount of the ambient temperature.

J Thermocouple Calibration Procedure °F using two known temperatures

• Connect the J thermocouple sensor to the logger
• Allow the J thermocouple sensor to stabilize at the first known (lower) temperature
• Read the Ambient Temperature of the Logger using the Realtime Screen
• Enter the first known temperature MINUS THE AMBIENT TEMPERATURE PLUS 32 °F in to the box labeled First Point Actual Value
• Click the First Point Button
• Allow the J thermocouple sensor to stabilize at the second known temperature
• Read the Ambient Temperature of the Logger using the Realtime Screen
• Enter the second known temperature MINUS THE AMBIENT TEMPERATURE PLUS 32 °F in to the box labeled Second Point Actual Value
• Click the Second Point Button
• The Calibration Offset and Calibration Gain figures will now be calculated and shown on the calibration screen.
• These Offset and Gain figures should now be written to the logger
• Click the Write Unit, Scaling and Calibration Values to logger button
• The Calibration process is now complete

If this procedure is used the J Thermocouple will show the correct temperature when sitting in free air.

If the ambient temperature is not subtracted from the known temperatures the J thermocouple will read high by the amount of the ambient temperature.