Traditional sensor sensitivity

1, the target of index evaluation is different:

The object of sensitivity evaluation is the relationship between the output and input of the sensor. Resolution refers to the sensor's ability to feel the smallest change being measured. Accuracy is used to evaluate the measurement accuracy of the sensor measurement system.

2. Different representations:

Sensitivity is expressed as the ratio of the output increment to the corresponding input increment that causes the increment. Use s to indicate sensitivity. It is the slope of the output-input characteristic curve. The dimension of sensitivity is the ratio of the dimensions of output and input. Resolution is usually measured by the maximum change of input quantity that can make the output change step by step in full scale. Accuracy is often expressed by accuracy.

3. Accuracy is the degree of dispersion of measured values; Displacement rate of sensitivity indicator relative to measurement change; Resolution is the smallest indication difference that display devices can effectively distinguish.

Accuracy: indicates the dispersion degree of the measured value. When a quantity is measured for an infinite number of times, the measurement results will present a normal distribution, as shown in the following figure. The accuracy of measuring instruments (including sensors) refers to the range of 99.73% possibility that the measurement results deviate from the true value (skip the discussion of statistical knowledge here). For measuring instruments, accuracy is a qualitative concept, which is generally not expressed by numbers.

Accuracy is also an instrument index similar to accuracy: it refers to the degree to which the average value measured many times is consistent with the true value under certain experimental conditions, expressed by error. For example:

The allowable error of the instrument is 0.5% of the range. That is, the accuracy is 0.5% or 0.5;

The allowable error of the instrument is plus or minus a certain value.

Accuracy and precision are similar, but their definitions are different. Accuracy is the degree of dispersion of measured values. Accuracy indicates how close the observed value is to the true value. "Accuracy" usually refers to accuracy in many cases.

Sensitivity: indicates the displacement rate of the finger (output) relative to the measurement change. Numerically, it refers to the change of the response of the measuring instrument divided by the corresponding excitation change. Because the sensitivity may be related to the excitation value. Therefore, different instruments will have different sensitivity values or expressions. For sensors, the threshold of the sensor (the minimum measured change that can make the sensor output change measurably) is often used to represent it.

Resolution: The minimum display difference that can be effectively resolved by a display device. For digital display devices, this is the change of the indicated value when the last significant digit changes. This concept also applies to recorders.

Extended data:

Other related indicators:

1, linearity: refers to the degree to which the actual relationship curve between sensor output and input deviates from the fitting straight line. It is defined as the ratio of the maximum deviation between the actual characteristic curve and the fitted straight line to the full-scale output value within the full-scale range.

2. Hysteresis: In the process of changing the input from small to large (positive stroke) and the input from large to small (reverse stroke), the phenomenon that the input-output characteristic curves of the sensor do not coincide is called hysteresis. For the same input signal, the output signals of the sensor before and after the stroke are not equal, and this difference is called hysteresis difference.

3. Repeatability: Repeatability refers to the degree to which the obtained characteristic curves are inconsistent when the input of the sensor changes continuously for many times in the same direction.

4. Drift: The drift of the sensor means that the output of the sensor changes with time when the input is unchanged, which is called drift. There are two reasons for the drift: one is the structural parameters of the sensor itself; Second, the surrounding environment (such as temperature and humidity, etc. )

References:

Baidu encyclopedia-sensor