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This article introduces the principle of NTC temperature measurement, hardware and software how to achieve, the content is very detailed, interested friends can refer to, hope to be helpful to you.

There are several commonly used temperature measurement schemes: digital temperature measurement chip, PT100, PT1000, thermocouple, NTC and so on. The cost of NTC temperature measurement is the lowest, but the accuracy is also the lowest, which is mainly used in places where the accuracy of temperature measurement is not high. Let's introduce NTC in combination with your own usage. 1. What is the NTCNTC thermistor with negative temperature coefficient, that is, its resistance becomes smaller with the increase of temperature, but its change trend changes exponentially, so the error is large, so it is not suitable for accurate measurement. The temperature-resistance curve of NTC is shown in the following figure.

Generally, the resistance of NTC at room temperature (25 ℃) is taken as the standard value, for example, the resistance of NTC at 100K is 100K at 25 ℃. The measurement method of 2.NTC NTC measurement should be divided into two steps: step one. The nominal resistance was measured at 25 ℃. For example, 100K NTC. Use the multimeter or resistance meter at 25 ℃, record the measured value and compare it with the nominal value; step 2. Measure its resistance at a specific temperature. For example: put 100K NTC in a constant temperature environment of 60 ℃ (it is recommended to use an oil tank for measurement, because the temperature of the oil tank is relatively constant) to measure its resistance, record the measured value and compare with the nominal value, the test resistance value should be about 24.5K; you can measure several more temperature points according to your own needs.

3. How to use N TC resistors NTC can be used to measure temperature when the accuracy of temperature measurement is not high. Generally, NTC resistors and certain resistors are in series. By measuring the voltage at both ends of the resistors, the resistance value of NTC can be calculated, and then the approximate temperature value of the current environment can be known. The circuit diagram is shown below.

The following is the program code I am using to deal with NTC data, first calculate the current NTC resistance value, and then convert it to temperature value. The B value of the NTC used is 3950, the single chip microcomputer is a 10-bit AD sampling, and the programming environment is IAR.

It should be noted that the linearity of the temperature measurement curve of NTC is not very good. In order to improve the accuracy, it needs to be processed in different temperature segments to prevent the temperature measurement error from being too large. With regard to the principle of NTC temperature measurement, how to realize the hardware and software is shared here. I hope the above content can be helpful to everyone and learn more knowledge. If you think the article is good, you can share it for more people to see.

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