Basic static characteristics of the sensor

In the inspection process control system and scientific experiments, various main parameters should be inspected and manipulated as much as possible, and it is reasonable to ensure higher quality control characteristics, and it is necessary to specify that the sensor can sense the change of the measured quantity without losing frames as much as possible. Converting this to relative power usage, this class defines the underlying characteristics of the core content sensor. The basic characteristics of the sensor are mainly divided into static data characteristics and dynamic characteristics.

Performance parameters reflecting the static data characteristics of the sensor

The static data characteristic refers to the relationship between the output of the system software and the input when the input of the monitoring system is a stable data signal that does not change with time. Including linearity, sensitivity, sluggishness, accuracy, drift, etc.

refers to the level at which the actual correlation curve between the sensor cardiac output and the input is offset from the fitted straight line.

Sensitivity is a key indicator value of the static data characteristics of the sensor. It is defined as the ratio of the adjustment of cardiac output, Δy, to the relative input adjustment, Δx, that caused the adjustment. It describes the change of the sensor's cardiac output caused by the change of the enterprise's input. Obviously, the greater the sensitivity S value, the more alert the sensor is.

The situation that the I/O characteristic comparison curve of the sensor does not persist during the period of change in input quantity from small to large (positive stroke arrangement) and input quantity from large to small (inverse stroke arrangement) is called sluggishness. In other words, for the input data signal of the same product specification, the sensor's front and back travel arrangements output data signals with different product specifications, and this error is called a lag error.

Accuracy refers to the inconsistency of the characteristic comparison curve obtained by individuals when the input quantity of the sensor is continuously changed several times in the same direction for full inspection.

The drift of the sensor means that the cardiac output of the sensor changes with time under the condition that the input quantity does not change. This condition is called drift. The reason for drift has two levels: one is the main parameters of the sensor itself; the other is the surrounding environment (such as temperature, relative humidity, etc.). The most common drift is temperature drift, that is, changes in cardiac output caused by changes in ambient operating temperature. Temperature drift is embodied in temperature zero drift and temperature sensitivity drift.

The temperature drift is generally used in the sensor work. The working temperature drift specification of the working temperature (usually 20 ℃), the ratio of the change of the output value to the temperature change.

The aspect between the minimum input amount that the sensor can measure and the relatively large input amount is called the detection level of the sensor.

The analytical geometric difference between the upper limit value and the lower limit value of the sensor detection level is called the inspection aspect.

The precision of the sensor refers to the reliable level of the measurement results, which is a comprehensive reflection of various deviations in the measurement. The smaller the deviation of accurate and precise measurement, the higher the precision of the sensor.

The precision of the sensor is described by the percentage of the relatively large basic deviation within the scope of its inspection to the full-scale output ratio. Error and random error are composed of two parts.

In architectural design, it is an expression of simple sensor precision, which cites the definition of precision. Accuracy is described in a series of normative percent index bins, implying a large tolerance for sensor side measurement.

If the working standard of the sensor deviates from the normal working standard, it will also cause additional deviation. The temperature additional deviation is the most critical additional deviation.

The ability of the sensor to detect the least amount of change in the input is called thinking ability. For some sensors, such as electromagnetic relay sensors, when the input volume changes continuously, the cardiac output only changes in the indoor stairs, and the thinking ability is the product specification of the input volume that each "indoor staircase" of the cardiac output means. For the digital display in-vehicle instrument panel, the thinking ability is the value that the last large number of the in-vehicle instrument panel identification value means. When the amount of change in the measured amount is lower than the thinking ability, the last digit of the digital display in-vehicle instrument panel will not change, and the original value of the fixed asset will still be identified. When thinking ability is described as a percentage of full scale output it is called texture.

Threshold value refers to the minimum measured input index value that can make the output of the sensor produce a measurable change, that is, the thinking ability around the zero point. Some sensors have serious discrete systems around the zero position, resulting in a "dead band", and the product specification of the dead band is used as the threshold; in many cases, the threshold core content sensor noise products specifications, so some sensors only output noise level.

Efficiency describes the expertise of a sensor to maintain its technical parameters over an extended period of time. The ideal situation is that no matter at that time, the main parameters of the sensor characteristics do not change with time. In fact, the characteristics of most sensors cause changes over time. This is due to the sensitive elements or the concrete works that make up the sensor, whose characteristics can vary greatly over time, thereby impairing the effectiveness of the sensor.

Benefit is generally described by the difference between the output of the sensor and the output of the start-stop timing after experiencing a required interval under the indoor temperature standard, which is called the benefit deviation. Benefit deviation can be described by relative error or absolute error.