Does the modern sensor in the principle and the structure the infinite variety, how act according to the concrete survey goal, the survey object as well as the survey environment selects the sensor reasonably, the question which is when carries on some quantity survey must first solve. After Self Drive Magnetic Transducer sensor determination, might also determine with it necessary measuring technique and the measurement equipment. Measurement result’s success or failure, is decided to a great extent in the sensor selects whether reasonably.
1st, determines sensor’s type according to the survey object and the survey environment
Must carry on – the concrete surveying work, must first consider that uses what kind of principle the sensor, after this needs to analyze various factor, can determine. Because, even if is the survey identical physical quantity, also has many kinds of principle sensors to be possible to supply to select, which one kind of principle’s sensor is more appropriate, below then needs according to survey the characteristic and sensor’s exploitation conditions consider some concrete questions: Measuring range size; Is measured the position to the sensor volume request; The measurement mode for the contact type is also the non-contact type; The signal draws out the method, wired or is the non-contact survey; Sensor’s origin, the domestic product imports, whether does the price withstand, independently develops.
After considering the above question can determine that selects what type SMD Transducer the sensor, then considers sensor’s concrete performance index again.
2nd, sensitivity choice
Usually, in sensor’s linearity range, hoped that sensor’s sensitivity is higher is better. Because only then the sensitivity is high time, with is surveyed the change correspondence the output signal value to be only then quite big, is advantageous to the signal processing. But must pay attention, sensor’s sensitivity is high, with is surveyed the ambient noise which has nothing to do with also to mix in easily, also will be enlarged by the amplifying system, affects the measuring accuracy. Therefore, requests the sensor itself to have the high signal-to-noise ratio, reduces as far as possible from the outside introduction unwanted signal.
Sensor’s sensitivity has the directivity. Mechanical Buzzer When by the survey is the unidirectional quantity, moreover is high to its directive request, should choose the other direction sensitivity small sensor; If by the survey is the multi-dimensional vector, then requests sensor’s overlapping sensitivity to be smaller is better.
3rd, frequency-response characteristic
Sensor’s frequency-response characteristic had decided frequency range which surveys, must in permit in the frequency range maintains not distorted. In fact sensor’s response always has – retards surely, the hope delay time is shorter is better.
Sensor’s frequency response is higher, the observable signaling frequency scope is wider.
In the dynamic measurement, should act according to the signal (stochastically the rectangle loudspeaker characteristic stable state, transient state, and so on) the response characteristic, in order to avoid has the oversized error.
4th, linearity range
Sensor’s linear scope refers to the scope which the output and the input are proportional. By theoretically says, within this scope, the sensitivity maintains a definite value. Sensor’s linearity range is wider, then its measuring range is bigger, and can guarantee certain measuring accuracy. When chooses the sensor, when sensor’s type determined that later must first look whether its measuring range does satisfy requests.
But in fact, any sensor cannot guarantee that the absolute linearity, its linearity is also relative. When requests the measuring accuracy is quite low, in certain scope, may the non-linear erroneous small sensor approximately regard as linearly, this will bring enormous convenient to the survey.
5th, stability
After the sensor uses period of time, its performance round loudspeaker maintains the invariable ability is called the stability. Affects the sensor long-term stability factor besides the sensor itself structure, is mainly sensor’s use environment. Therefore, must enable the sensor to have the good stability, the sensor must have the strong environment adaptiveness.
Before choosing the sensor, deals with its use environment to carry on the investigation, and according to the concrete use environment choice appropriate sensor, or takes the suitable measure, reduces the environment the influence.
Sensor’s stability has the quota target, after surpassing the lifetime, should carry on the demarcation before the use, by determined whether sensor’s performance does change.
In certain requests the sensor to be able the long-term use, but also cannot replace or the demarcation situation easily, selects the sensor stability request is stricter, must be able to undergo the long time the test.
6th, precision
The precision is a sensor’s important performance index, it is relates the entire measurement system measuring accuracy an important link. Sensor’s precision is higher, its price is more expensive, car receivers therefore, sensor’s precision, so long as satisfies the entire measurement system’s accuracy requirement to be possible, does not need to elect excessively high. Like this may in satisfy the identical survey goal in many sensors to choose quite cheap and simple sensor Arter the Russ air compressor fitting.
If the survey goal is the qualitative analysis, selects the repeat accuracy high sensor then, is not suitable selects the absolute magnitude precision high; If for the quantitative analysis, must obtain the precise observed value, must select the precision class to be able to satisfy the request the sensor.
To certain special use situation, is unable to elect to the appropriate sensor, then must independently design the manufacture sensor. The self-made sensor’s mini receiver performance should satisfy the operation requirements.
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