Metrological Procedure
Sequential temperature changes applied to a sensor system verify the accuracy of the output across a specified operating range. During thermal step calibration, the instrument dwells at fixed intervals until equilibrium is reached. This process identifies the temperature coefficient of the sensitivity and the zero-point shift.
Gradient Management
Rapid transitions between setpoints reveal the transient response and the time constant of the device. Executing a thermal step calibration requires precise control of the soak time to ensure that internal components have fully stabilized. Insufficient waiting periods lead to hysteresis errors in the final data.
Drift Quantification
Comparing the initial and final room-temperature readings provides a measure of the permanent offset induced by thermal cycling. The results of thermal step calibration allow for the creation of compensation algorithms in the sensor firmware. These corrections maintain signal integrity in fluctuating environments.
This verification routine ensures that the device maintains its specified accuracy even after exposure to extreme environmental shifts during transport or operation.
System Boundary
Success depends on the stability of the reference thermometer and the uniformity of the climate chamber. If the thermal step calibration environment contains significant spatial gradients, the resulting coefficients will be invalid for field use. Calibration certificates must specify the ramp rate and the stabilization criteria used.
