My aim is to investigate at which temperatures will give me which resistance and present it as a graph.

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Thermistor Investigation

Aim

My aim is to investigate at which temperatures will give me which resistance and present it as a graph.

Prediction

I predict that the graph I will produce will show me that there is a clear relationship between the temperature and the resistance of the thermistor.  Whether it is a negative coefficient or a positive coefficient will depend on whether thermistor is a negative temperature coefficient (NTC) thermistor or a positive temperature coefficient (PTC) thermistor.  I have not been told which thermistor it is that I have been given and

therefore I will also find out which thermistor I have been given.

Research

After time, temperature is the variable most frequently measured. The three most common types of contact electronic temperature sensors in use today are thermocouples, resistance temperature detectors (RTDs), and thermistors. This article will examine the negative temperature coefficient (NTC) thermistor.  Positive temperature coefficient (NTC) thermistor does the same as NTC thermistor accept the resistance goes up when the temperature rises.

NTC thermistors are manufactured in a variety of sizes and configurations. The chips in the center of the photo can be used as surface mount devices or attached to different types of insulated or uninsulated wire leads. The thermistor element is usually coated with a phenolic or epoxy material that provides protection from environmental conditions. For applications requiring sensing tip dimensions with part-to-part uniformity and/or smaller size, the devices can be encapsulated in PVC cups or polyamide tubes.

General Properties and Features

NTC thermistors offer many desirable features for temperature measurement and control within their operating temperature range. Although the word thermistor is derived from thermally sensitive resistor, the NTC thermistor can be more accurately classified as a ceramic semiconductor. The most prevalent types of thermistors are glass bead, disc, and chip configurations (see Photo above).

NTC thermistors exhibit a decrease in electrical resistance with increasing temperature. Depending on the materials and methods of fabrication, they are generally used in the temperature range of -50°C to 150°C, and up to 300°C for some glass-encapsulated units. The resistance value of a thermistor is typically referenced at 25°C (abbreviated as R25). For most applications, the R25 values are between 100 and 100 k. Other R25 values as low as 10 and as high as 40 M can be produced, and resistance values at temperature points other than 25°C can be specified.

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Equipment

In this experiment I used the following: 1x kettle, 1x thermistor, 1x multimeter, 2x crocodile clips, some ice cubes, 1x large beaker and 1x thermometer.

Method

Step1: - Set up the experiment as shown in the diagram above.

Step 2: - To get the correct temperature of the water in the beaker use both the ice the kettle until the thermometer reads the desired temperature.

Step 3: - I then used the multimeter set at 2000 ohms to take a ...

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