Vernier Thermocouples have been updated a few times since they first began shipping.

In September 2016, we changed the calibration from linear to 2nd order polynomial to get better accuracy. These units have model number TCA1816R3 on the label. Logger Pro 3.11, Logger Lite 1.9, and LabQuest App 2.7 are the first versions of our software to support this new model.

Units shipped after September 2016 have the following calibration equations:

Calibration ‘Thermocouple °C’:
     Equation: 2nd Order Polynomial
     y = cx^2 + bx + a
     a: -185.19
     b: 311.32
     c: -1.7873

Calibration ‘Thermocouple °C Low’:
     Equation: 2nd Order Polynomial
     y = cx^2 + bx + a
     a: -274.27
     b: 640.14
     c: -305.66

Calibration ‘Thermocouple °C High’:
     Equation: 2nd Order Polynomial
     y = cx^2 + bx + a
     a: -7.7423
     b: 195.71
     c: 16.904

Units shipped before September 2016 have the following calibration equations:
Thermocouple °C
     * Intercept: -196.88
     * Slope: 327.360

Thermocouple °C Low
     * Intercept: -323.956
     * Slope: 514.839

Thermocouple °C High
     * Intercept: -284.075
     * Slope: 353.501

Units were also updated in spring 2004. Previous models had two wires, while the 2004 and newer model has only one wire. Logger Pro 3.3 and Logger Lite 1.2 are the first versions of our software to support this model.