Modeling the response of Thermistor - A Preview

Investigating the Steinhart-Hart equation by calibration of the thermistor and its mathematical modeling

Description

A thermistor is a semiconductor used to measure temperature. Its resistance depends on the temperature. The goal of the present experiment is to determine the resistance R as a function of temperature T. You are expected to come up with a mathematical model that can predict the temperature from the measured resistance.

Overview

  • Simultaneous temperature and resistance measurement
  • Investigating the Steinhart-Hart equation
  • Calibration of a thermistor
  • Mathematical modeling of a sensor
  • Nonlinear curve fitting
  • Behavior of semiconductors

How Does it work?

A beaker containing water is placed on a hot plate with the thermistor and a calibrated thermocouple probe immersed in heating water. PhysLogger is connected to the thermocouple via PhysTherm and to the thermistor via an R Probe. Once the hot plate is switched on, the water starts to heat up. The temperature and resistance values are collected and plotted, providing an intuitive understanding of the trend and relation between the temperature and resistance of the thermistor. The data is used to develop and fit a mathematical model of R(T), which is used to determine the temperature coefficients. The analysis of the data acquired from the PhysLogger is given below.

Graphs
Linear Fit

Parts Included

  • Thermistor
  • Hot plate (third plate)
  • R Probe and PhysTherm with K-type thermocouple
  • PhysLogger
  • Lab stand, beaker, and connecting wires

>You can get the PDF version of the brochure by clicking on this link.