Introduction To The Five Characteristics Of The Sensor

1. Static characteristics: refers to the relationship between the output and input of the sensor for the static input signal. Because the input quantity and output quantity have nothing to do with time at this time, the relationship between them, that is, the static characteristics of the sensor can be used as an algebraic equation without time variable, or the input quantity is used as the abscissa, and the corresponding output quantity is used as The characteristic curve drawn on the ordinate is used to describe. The main parameters that characterize the static characteristics of the sensor are: linearity, sensitivity, resolution and hysteresis.

2. Dynamic characteristics: refers to the characteristics of the output of the sensor when the input changes. In actual work, the dynamic characteristics of a sensor are often expressed by its response to some standard input signals. This is because the response of the sensor to the standard input signal is easy to obtain experimentally, and there is a certain relationship between its response to the standard input signal and its response to any input signal, and the latter can often be inferred by knowing the former. The most commonly used standard input signals are step signal and sinusoidal signal, so the dynamic characteristics of the sensor are often expressed by step response and frequency response.

3. Linearity: Usually, the actual static characteristic output of the sensor is a curve rather than a straight line. In actual work, in order to make the meter have a uniform scale reading, a fitting straight line is often used to approximately represent the actual characteristic curve, and the linearity (non-linear error) is a performance index of this approximation. There are many ways to choose the fitting line. For example, the theoretical straight line connecting the zero input and full-scale output points is used as a fitted straight line; or the theoretical straight line with the smallest square sum of deviations from each point on the characteristic curve is used as a fitted straight line. This fitted straight line is called the least squares method. fit straight.

4. Hysteresis characteristic: It characterizes the degree of inconsistency of the output-input characteristic curve of the sensor between the forward (input volume increase) and reverse (input volume decrease) strokes, usually using the maximum difference between the two curves △ MAX Expressed as a percentage of the full scale output F?S. Hysteresis can be caused by energy absorption in the sensor's internal components.

5. Sensitivity: Sensitivity refers to the ratio of the output change △y to the input change △x of the sensor under steady-state operation. It 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 vary with the amount of input.