What are the concepts of temperature sensor resolution, sensitivity and accuracy?

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What are the concepts of temperature sensor resolution, sensitivity and accuracy? [Copy link]

Usually, we often mention the three parameters of temperature sensors, such as resolution, sensitivity and accuracy. But many people are not very clear about the difference between these three parameters, which leads to problems of varying sizes when using them. Below, we will briefly introduce the differences between the sensitivity, accuracy and resolution of sensors.

What are the concepts of resolution, sensitivity and accuracy of temperature sensors? Resolution Concept: It refers to the ability of the sensor to sense the smallest change in the measured value. In other words, if the input changes slowly from a non-zero value. When the input change value does not exceed a certain value, the output of the sensor will not change, that is, the sensor cannot distinguish the change in this input. The output will change only when the change in input exceeds the resolution. Resolution is usually understood as the accuracy of A/D conversion or the minimum change that can be perceived, while accuracy usually refers to the percentage obtained by dividing the error of A/D, sensor circuit and other factors by the displayed percentage. Digital instruments are usually determined by the number of bits of the A/D converter. Accuracy is the maximum percentage error of the sensor when repeatedly measuring the same standard value. It is an indicator of accuracy after calibration. Resolution is several times better than accuracy. Sensitivity Concept: It refers to the ratio of the output change △y to the input change △x of the sensor under steady-state working conditions, that is, the ratio of the output and input dimensions. For example, for a displacement sensor, when the displacement changes by 1mm, the output voltage changes by 200mV, then its sensitivity should be expressed as 200mV/mm. Sensor sensitivity is the slope of the output-input characteristic curve. If there is a linear relationship between the output and input of the sensor, the sensitivity S is a constant. Otherwise, it will change with the change of input quantity. When the output and input quantities of the sensor have the same dimension, the sensitivity can be understood as the magnification. Increasing the sensitivity can obtain higher measurement accuracy. However, the higher the sensitivity, the narrower the measurement range and the worse the stability. Accuracy Concept: It refers to the ratio of the value of plus or minus three times the standard deviation near the true value to the range, which refers to the maximum difference between the measured value and the true value; resolution - the minimum measured value that causes the indication to change; should be separated from the sensitivity coefficient (sensitivity coefficient - refers to the ratio of output to input) The accuracy of general domestic temperature sensors is divided into two levels, A and B. The national standard stipulates as follows: According to the difference between the output value of the sensor and the true value of the measured temperature, it is divided into Class A: not more than ± (0.15℃ + 0.002 * sensor range); Class B: not more than ± (0.30℃ + 0.005 * sensor range). Therefore, if higher measurement accuracy is required, a sensor with a smaller range should be selected. Resolution is "usually determined by the number of bits of the A/D converter" or the last bit of its output value. Usually, the resolution of the sensor at each point in the full range is not the same. Therefore. The maximum change in the input value that can cause a step change in the output in the full range is often used as an indicator to measure resolution. If the above indicator is expressed as a percentage of the full range, it is called resolution. Resolution is negatively correlated with the stability of the sensor.

lct2000

I support it. Many people don't understand the relationship between resolution and accuracy. Thanks for popularizing it.

Multi-point DS18B20 temperature acquisition module LCT2662M and instrument LCT2201C