Model 372 and Sensor Performance

Excitation ranges in sensor tables were selected to minimize sensor self-heating.
Excitation power = actual current² × example resistance

Measurement resolution comes from electronic instrumentation and sensor thermal noises. Measurement resolution is given by:
Resolution (Ω) = ((instrument noise)²+(sensor thermal noise)²)^0.5

Electronic accuracy is influenced by the measurement range used and sensor resistance value. Electronic accuracy is given by:
Electronic accuracy (Ω) = Accuracy (%) × example resistance + 0.005% of resistance range
Where: Accuracy (%) is given in the instrument performance table at the selected current and voltage range

Self-heating errors are measurement errors due to power dissipation in the sensor causing unwanted temperature rises.
Self-heating error is given by:
Self heating error = thermal resistance × power
Thermal resistances specified are typical values resulting from minimal heat sinking.
Improved values can be achieved with permanent installation.

Calibration accuracies are based on Lake Shore sensor calibration uncertainty and repeatability values—see Appendices B, D & E of the Temperature Measurement and Control Catalog for more information.

Interpolation errors are due to the linear interpolation method used by the Model 372 to convert resistance values to temperatures when using a temperature sensor. These errors are not present when resistance is measured directly.

Overall accuracy is a combination of all listed sources of potential error and is given by:
Overall accuracy = (measurement resolution² + electronic accuracy² + self heating errors² + calibration accuracy² + interpolation error²)^0.5

Lake Shore Rox™ RX-102B-CB with 0.02 to 40 K calibration

Values given are for measurement input. If the value is different for the control input, it is shown in blue.

Lake Shore GR-50-AA with 0.05 to 6 K calibration

Values given are for measurement input. If the value is different for the control input, it is shown in blue.

Lake Shore CX-1010-SD with 0.1 to 325 K calibration

Values given are for measurement input. If the value is different for the control input, it is shown in blue.