Sensor Improved Sensitivity And High Measurement Accuracy
Acceleration sensor is a kind of sensor which can measure acceleration. It is usually composed of mass block, damper, elastic element, sensitive element and adjusting circuit. In the process of acceleration, the acceleration value is obtained by using Newton's second law to measure the inertia force of mass block. According to the different sensor sensors, the common accelerometer includes capacitance type, inductance type, strain type, piezoresistive type, piezoelectric type and so on.
is the ratio of the output change Y to the input variable x, that is, the ratio of the output to the input quantity in the steady state operation of the sensor. For example, a displacement sensor, when the displacement changes 1mm, the output voltage changes to 200mV, then its sensitivity should be expressed as 200mv/mm.
Sensor sensitivity is the slope of the output-input characteristic curve. If the output of the sensor is linearly related to the input, the sensitivity s is a constant. Otherwise, it will change with the amount of input.
When the output of the sensor and the dimension of the input quantity are the same, the sensitivity can be understood as the magnification. The sensitivity can be improved and the measurement accuracy is higher. But the higher the sensitivity, the narrower the range of measurement, the worse the stability is often.
The sensor is capable of sensing the smallest change in measurement. That is, if the input is slowly changing from a value other than 0. When the input change value does not exceed a certain value, the output of the sensor will not change, that is, the sensor changes to this input is not discernible. The output changes only when the input changes beyond the resolution.
Resolution is generally understood to be a/D conversion precision or the smallest change can be perceived and precision usually refers to: A/d, sensing circuit other factors such as integrated factors, the error divided by the percentage shown.
The digital instrument usually depends on the number of digits of a/D converter to measure the maximum percent error of the same standard value, which is more than several times the accuracy of the calibrated measurement.
In general, sensors have different resolutions at each point within the full range. therefore。 The maximum change value in the input quantity which can produce the step change of output volume in the full range is used as the measure of the resolution. The above indicator is called resolution if it is expressed as a percentage of the full range. The resolution is negatively correlated with the stability of the sensor.