• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigate the variation of the resistance of a thermistor with different temperatures.

Extracts from this document...

Introduction

Kiron Nandhra 12KFA

Advancing Physics 7285

Instrumentation Task

Sensor Project

Introduction

For this experiment I am going to investigate the variation of the resistance of a thermistor with different temperatures. The resistance will be tested at every 5 degrees, with a range from 90 C down to 5 C, and these results will be recorded. After recording the results, the experiment will be repeated at a total of 3 times, this is so we can get an average that should be correct and accurate.

Plan: Sensor circuit

The following below, are what are needed for me to complete my task:

  • One thermistor
  • Digital multi-meter with a setting to read resistance in Ohms to 2 decimal places

The sensor circuit’s purpose is to sense the change in temperature in a domestic water tank. For example it will be able to sense and recognise when the water is very close to boiling point and if it has dropped to close to freezing point. If it gets to hot, the sensor would cause the heater to be switched off. If it gets too cold, the sensor would cause the heater to be switched on, so avoiding the risk of burst pipes due to freezing. On separate circuits there will be many thermistors flooded in the water at different points, so we are able to find an overall temperature in the tank.

...read more.

Middle

Hypothesis

I predict, therefore that the resistance in any experiment will rise as the temperature of the water falls.

Results

Temperature

Resistance

Resistance

Resistance

Resistance

(C)

(Ohms)

(Ohms)

(Ohms)

(Ohms)

...read more.

Conclusion

To improve this, we would use an Amplifier, which alerts the danger much faster. A thermistors response time is usually slow, however, with the aid of an Amplifier, problems will be alerted much sooner. It works by sensing on small changes in resistance through the thermistor. The amplifier then picks up on this, then amplifying the current at a much faster speed so the circuit responds quicker. When the temperature exceeds 65 C or drops below 25 C, my circuit will recognise this and respond by passing the information to an additional circuit, which will respond by cooling or heating the water. Heating if below 25 C, or cooling if above 65 C.

My circuit would look like this. It’s a circuit from ‘Advancing Physics A1, IOP Publishing’      

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Electrical & Thermal Physics essays

  1. Marked by a teacher

    Sensing project

    5 star(s)

    To make the graph firstly the mean average (found by adding together the frequency of the data and number it by the number of pieces of data) of the results must be taken this decreases the chance of any singular anomalies results becoming apparent in the graph.

  2. Investigate how the temperature affects the resistance of a thermistor.

    Preliminary Test: In my preliminary tests I needed to find out; o The best possible way of heating the thermistor o The range and size of data I record o What the resistance need to be measured in ie.

  1. To investigate how the temperature affects the resistance of a thermistor.

    One factor that must be kept constant during my experiment is the voltage and current in the circuit. This need to stay the same because I am changing the temperature in order to investigate the resistance of the thermistor and because both voltage and current affect the resistance in a

  2. Investigate the relationship between temperature and resistance in a thermistor.

    Our results are reliable enough to support my prediction and to draw a detailed analysis. They are reliable to a reasonable degree of accuracy because we took three results and then found the average. We also know they are quite accurate as the line of best fit goes close to all the points.

  1. Characteristics of Ohmic and Non Ohmic Conductors.

    Thickness - 0.45 mm and length 80 cm * Rheostat * Crocodile Clips From this we can notice the difference in the actual apparatus I have listed before. Below given are the differences in the specifications in difference to carry out the experiment for the IV characteristics for the metallic wires.

  2. Experiments with a thermistor

    First of all, I immersed each thermistor into Beaker 1 and after sometime, I transferred the thermistor into Beaker 2, noting the time taken for the digital multi-meter to reach a steady voltage value. The values taken are shown below: Time Taken For Multi-Meter To Read A Steady Value/s Bead

  1. An Investigation into the Resistance of a Thermistor, its Application as a Sensor and ...

    As can be seen this confirms the theory suggested above. To ensure that this was not a fluke, the same procedure was followed in order to achieve a voltage of 1V at 50�C and 4V at 70�C. According to our table, at 50C, the resistance of the thermistor is 180C.

  2. I am going to investigate what the resistivity is of a pencil lead. ...

    I will use exactly the same equipment throughout the experiment as different wires have different diameters and length while the meters may all vary slightly. The temperature of the pencil lead will affect the resistance. It is especially important that this remains the same as materials that are ohmic resistors,

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work