Testing thermistor and calibration - sensors

[meawinner]

Hi please help I have to do a piece of coursework on sensors. I am testing a thermistor and my teacher mentioned something about calibration but I don't know what it is can someone help please. I have taken results for the resistances for every ten degrees from 0 to 150

 

[HallsofIvy]

Please do not post the same question in different fora.

To "calibrate" an instrument simply means to determine how the reading of the instrument correspond to actual values of the quantity being measured. For example, if you made your own thermometer by, for example, putting mercury in a thin tube, you would have to determine what height of mercury corresponded to what temperature before you could start. Even instrument that appear to be reporting the value directly need to be calibrated: I got on a scale the other day and, to my amazement it read exactly what I consider to be my ideal weight. Unfortunately, I found out that it wasn't "calibrated" properly and was reading about 10 pounds low!

You calibrate an instrument by using it to measure something that you already know. A thermometer in a factory might be calibrated by comparing it to another thermometer that has been previously calibrated.

A person in the physics forum where you also posted this (and so my first sentence above) suggested that you put your sensor in ice-water which must have temperature 0 degrees C. I would recommend that you also put it in boiling water which must have temperature 100 degrees C. Those two values should allow you to determine the reading for other temperatures.

 

[M98Ranger]

Sure, I'd be happy to help! Calibration is the process of adjusting or setting a device to a known standard or reference, in order to ensure its accuracy and reliability. In the case of sensors, calibration involves comparing the sensor's output to a known standard or reference and adjusting it if necessary. This is important because sensors can sometimes become less accurate over time or due to environmental factors.

In your case, you are testing a thermistor, which is a type of temperature sensor that works by changing its resistance as the temperature changes. To calibrate a thermistor, you would need to compare its resistance readings at different temperatures to a known standard, such as a calibrated thermometer. This will allow you to determine if the thermistor is accurately measuring temperature and make any necessary adjustments.

It's great that you have taken results for the resistances at different temperatures. This will allow you to plot a graph and compare it to a known standard to see if the thermistor is accurately measuring temperature. If there are any discrepancies, you may need to calibrate the thermistor by adjusting its resistance values. Your teacher should be able to provide guidance on how to do this.

Overall, calibration is an important step in ensuring the accuracy and reliability of sensors. It may seem like a small detail, but it can make a big difference in the results and data collected by the sensor. I hope this helps and good luck with your coursework!