Elaborate on the sensitivity and resolution of sensors

Sensitivity of sensors

Sensitivity refers to the ratio of the change in output quantity △ y to the change in input quantity △ x of a sensor under steady-state operating conditions.

It outputs the slope of an input characteristic curve. If there is a linear relationship between the output and input of the sensor, then the sensitivity S is a constant. Otherwise, it will change with the variation of input quantity.

The dimension of sensitivity is the ratio of the dimensions of the output and input quantities. For example, if a displacement sensor outputs a voltage change of 200mV when the displacement changes by 1mm, its sensitivity should be expressed as 200mV/mm.

When the output and input dimensions of the sensor are the same, sensitivity can be understood as amplification factor.

Improving sensitivity can achieve higher measurement accuracy. But the higher the sensitivity, the narrower the measurement range, and the poorer the stability.

Resolution of sensors

Resolution refers to the ability of a sensor to perceive small changes in the measured data. That is to say, if the input quantity slowly changes 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 quantity. The output will only change when the change in input exceeds the resolution.

Usually, the resolution of sensors at different points within the full range is not the same, so the large change value in the input quantity that can cause a step change in the output quantity in the full range is commonly used as an indicator to measure the resolution. If the above indicators are expressed as a percentage of full scale, they are called resolution.