Description of Static and Dynamic Characteristics of Sensors - Brand [Veckway]

sensorThe characteristics refer to the general term for the unique properties of sensors. And the input of the sensor-The output characteristic is its basic characteristic. Generally, when sensors are studied as a two terminal network, the input-output characteristic is the external characteristic of the two terminal network, that is, the correspondence between the input and output quantities. Due to the different states of input action (static, dynamic), the sameJThe input represented by a sensor-The output characteristics are also different, so there are static characteristics and dynamic characteristics. Due to differencessensorThe internal parameters of each are different, and their static and dynamic characteristics also exhibit different characteristics, which have varying impacts on the measurement results. Therefore, starting from analyzing the external characteristics of sensors, analyzing their working principles, the relationship between input-output characteristics and internal parameters, the causes and patterns of errors, and the range relationship are important contents. This chapter mainly studies input-output characteristics from both static and dynamic perspectives.

Static characteristics refer to when the input quantity is constant or changes very slowlysensorinput-Output characteristics. Dynamic characteristics refer to the input-output characteristics of a sensor when the input quantity changes over time.

The main indicators for measuring the static characteristics of sensors are linearity, hysteresis, repeatability, resolution, stability, and temperature stability Sexual, various anti-interference abilities, etc.The static characteristic curve can be obtained from actual testing, and after obtaining the characteristic curve, it can be said that the problem has been solved. But in order to For the convenience of calibration and data processing, various methods can be used to obtain linear relationships, including computer hardware and Software compensation, perform linearization processing. Generally speaking, these methods are relatively complex, so in cases where the nonlinear error is not too large In this case, the linear fitting method is always used for linearization.

In reality, a large number of measured signals are dynamic signals, and whether the output of the sensor can well follow the changes in the input quantity is crucial A very important question. Although some sensors have excellent static characteristics, they cannot follow the rapid changes in input quantity well And it leads to serious errors. If this dynamic error is not carefully controlled, it can reach tens or even hundreds of percent, which requires We pay close attention to the dynamic response characteristics of sensors.

The study of dynamic characteristics can be analyzed using transient response method and frequency response method from both time domain and frequency domain perspectives. Due to inputThe time function forms of signals are diverse and can be studied in the time domainsensorWhen studying the response characteristics, only a few specific ones can be studied Input the response characteristics of time functions such as step functions, pulse functions, and ramp functions. Studying dynamic characteristics in the frequency domain can It is convenient to obtain frequency response characteristics using a sine signal generator and precision measuring equipment. Good dynamic characteristicssensorShould have Short transient response time or should have a wide frequency response characteristic.

In researchsensorWhen it comes to the dynamic characteristics of, in order to facilitate comparison and evaluation, the commonly used input signal is the unit step input Quantity and sine input quantity. The analysis and dynamic calibration of the dynamic characteristics of sensors often use these two standard input signals.

Most sensors are linear or considered linear systems within a specific range. Analyzing the dynamic response of linear systems When describing characteristics, mathematical methods can be used.