A digitally linearized thermistor thermometer referenced to IPTS-68

Area of Science:

• Instrumentation and Measurement
• Thermometry
• Sensor Technology

Background:

• Accurate temperature measurement is critical across scientific and industrial applications.
• Existing thermistor thermometers can suffer from nonlinearity and self-heating errors.
• Traceability to international standards ensures measurement reliability.

Purpose of the Study:

• To introduce a digitally linearized thermistor thermometer with enhanced accuracy and low power consumption.
• To detail the design and performance characteristics of the novel thermometer probe.
• To ensure the thermometer's traceability to the International Practical Temperature Scale of 1968 (IPTS-68).

Main Methods:

• Digital linearization techniques applied to thermistor resistance data.
• Development of a compact, immersible thermistor probe (1.5 mm diameter, 10 cm length).
• Implementation of heat sinking strategies to minimize self-heating errors.

Main Results:

• Achieved accuracy of +/- 0.01 degrees C within the 0 to 60 degrees C range.
• Operates at a low wattage of 50 microW with a 1 s sampling time.
• Self-heating error is less than 5X 10(-3) degrees C across a wide power range (1-50 microW).

Conclusions:

• The digitally linearized thermistor thermometer provides a highly accurate and reliable temperature sensing solution.
• The probe design and low power operation make it suitable for sensitive applications.
• Digital linearization effectively mitigates inherent thermistor nonlinearities and self-heating effects.