1, the basis is measured object and measure an environment to decide the type wants to undertake - specific measurement works, should consider to use above all why to plant the sensor of the principle, ability is affirmatory after this need analyses the element of many sided. Because, even if measure same physical quantity, the sensor that also has a variety of principles can be offerred choose, the sensor of which kind of principles is more appropriate, the use condition consideration that needs the characteristic that the basis is measured and sensor is a few more the following specific issue: The size; of span is measured the derivative method that the position measures means to be contact to the requirement; of sensor bulk or is not contact; signal, wired or the origin that dispute contact measures; sensor, homebred still import, the price whether bear, still develop by oneself. Can choose certainly after considering afore-mentioned issues why to plant the sensor of the type, consider the particular function target of sensor again next. 2, the choice of basis sensitivity normally, inside the linear limits of sensor, the sensitivity of hope sensor has been jumped over higher. Because have only when sensitivity is tall, the as corresponding as change be metricaled value that outputs signal just is compared big, be helpful for signal processing. But those who want an attention is, the sensitivity of sensor is tall, as easy also as the outside noise that is measured to have nothing to do interfuse, also can be magnified the system magnifies, the influence measures precision. Accordingly, requirement sensor itself should have taller letter a confusion of voices to compare, reduce the interference signal that introduces from the outside as far as possible. The sensitivity of sensor is tropism of in the right way. Should be measured to be one-way quantity, and directional to its demand is higher, if be measured,should choosing the sensor; with other direction small sensitivity is multidimensional vector, ask the alternate sensitivity Yue Xiaoyue of sensor is good. 3, the frequency limits that judges frequency to answer the frequency of characteristic sensor to answered character to decide to be measured, must be in allow frequency keep not lack fidelity inside limits. Actually of sensor answer always have - calm defer, it is better to hope defer time is shorter. The frequency of sensor is answered taller, the signal frequency range that can measure is wider. Measure in trends in, should the characteristic according to signal (stable state, transient state, random etc) answer character, lest had produced big error. 4, the line form limits of the linear limits sensor according to sensor is to point to output and the limits that input direct ratio. With theoretic tell, inside this limits, sensitivity holds calm cost. The linear range of sensor is wider, criterion its span is bigger, and can assure certain measurement precision. When choosing sensor, want to see its span whether satisfy a requirement above all later certainly when the sort of sensor. But actually, any sensor are unwarrantable absolutely linear, its degree of linearity also is opposite. When place the requirement is measured when precision is lower, inside certain limits, but will nonlinear the sensor with minor error regards linear approximately, this meeting gives measure bring huge to go to the lavatory. 5, after using period of time according to the stability sensor of sensor, its function maintains changeless ability to call stability. The element of long-term stability divides influence sensor outside sensor itself structure, basically be the use environment of sensor. Accordingly, want to make sensor has good stability, sensor must want to stronger environment gets used to ability. Before choosing sensor, answer its to use an environment to undertake investigating, choose appropriate sensor according to particular use environment, or take proper step, reduce environmental effect. 6, a the precision of sensor cannot ignore precision is sensor main function index, it is to matter to whole a when measure a system to measure precision important segment. The precision of sensor is taller, its price is higher, accordingly, the precision of sensor should be satisfied only whole the precision demand that gauges a system is OK, need not choose exorbitantly. Can satisfying so same the choice in a lot of sensor that measures a purpose compares petty gain and simple sensor Atelasi is empty press fittings. If measure the purpose is qualitative analysis, choose repeat the sensor with tall precision can, unfavorable if be for quantitative analysis,choose the; with tall precision of sheer value of a quantity, must obtain exact measured value, need to choose accuracy class to be able to satisfy the sensor of the requirement. CNC Milling