are listed from top to bottom starting with input five and ending with input one (except for input three). Enter the desired trim value, and, if necessary, press the circular arrow key to toggle the sign of the trim value. Press the Enter key to set the new trim value. Note – The overall Cold Junction value, as well as any trim value, is modified by adding or subtracting a value to the current value.
Input Board Version 1.08 and higher
The functionality of the Cold Junction Trim menu screen is similar to the Cold Junction trim for the input board versions 1.07 and below. The difference is that the new boards have five thermisters, instead of only one, so each board must have five cold junction trims performed. The middle of the screen will look like the following:
Input 5 trim value Input 4 trim value Input 3 trim value Input 2 trim value Input 1 trim value
See the section To Perform a Cold Junction Calibration below for details on performing the cold junction calibration. Press the down arrow to highlight the input to be trimmed. Enter the desired cold junction trim value, and, if necessary, press the circular arrow key to toggle the sign of the cold junction value.
Press the Enter key to begin the cold junction trim. While the system is working, the word “Busy” will appear below the “Input 1 trim value” line. When the trim has finished, “Busy” will disappear.
Firmware Revision 1.11 and above
With Firmware revision 1.11, the title of the menu option 23 has become “CJ Calibration” instead of “Cold Junction Trim”.
To Perform a Cold Junction Calibration
The user will need a thermocouple calibrator capable of outputting a thermocouple signal to calibrate the cold junction value of the data logger. The user will need to connect the calibrator to one of the inputs on the data logger for the channel that will be calibrated. It is recommended to let everything (calibrator and datalogger) sit for approximately thirty minutes to allow the temperature to achieve equilibrium. Set up the calibrator for the specific thermocouple type of the thermocouples in the datalogger, i.e. type K, type J, etc. Then, source a specific temperature, like 1000 °F to the connected input. It is recommended that the actual temperature used be similar to an appropriate process temperature. For example, if your
Super Systems Inc. | Page 34 | SDS Data Logger Manual #4565 Rev D |