The magnetostrictive technology position sensor 

　　 Contactless position sensor is a revolutionary improvement of position sensor which based on electric potential technology.It use magnetostrictive technology and upgrade a lot no matter in the interface or performance. Do you know the technology of the magnetostrictive position sensor? The first step is to understand the  position sensor, also known as liner sensor,converts displacement into electricity. Position sensor is a liner device belonged to the metal induction and its role is to convert the physical values to be measured into electricty.  They can be devided into inductive position sensor, capacitance position sensor, photoelectric position sensor, ultrasonic position sensor, hall position sensor. 

　　In the conversion process, many physical values need to be transformed into displacement firstly such as pressure, flow rateand acceleration , and then convert the displacement into electricity. So position sensor is an important kind of basic sensors. In the process of production , position measurement is generally classified into physical size measurement and mechanical displacement . Mechanical displacement includs line displacement and angular displacement. According to the transform form of  physical values to be measured, position sensor can be divided into analog and digital sensor. Analog can be divided into property type (such as electricity type) and structural type. Common used position sensor is mainly analog structure sensor, including potentiometer position sensor, inductive position sensor (see inductive sensor), selsyn, capacitive position sensor (see capacitive sensor), electricity eddy position sensor (see the eddy current sensor), hall position sensor etc.One of the important advantages  of digital position sensor is that it is convenient to send signal into computer system(see digital sensor).Its development is fast and application is wider and wider(see inductive synchronizer, code salver, grating sensor, magnetic ce-grate sensor). 

　　Potentiometer position sensors which use the potentiometer elements to convert mechanical displacement into resistance or voltage of linear or any function relationships and then output it. Ordinary line potentiometer and circular potentiometer can be used as linear position and angular position sensor. But the potentiometer which is designed to  realize the displacement measurement requires a definite relationship between displacement and resistance. The move brush of the potentiometer displacementsensor on figure 1 is connected to the object to be tested. The displacement of the object  will change the resistance of the moving port on the potentiometer .The variation of resistance  reflects the displacement andincrease or decrease show the direction of the displacement. Usually the potentiometer is supplied with power to convert the change of resistance into voltage output. The output characteristic of wire wound type potentiometer also shows stepped-weir because when the brush is moving ,resistance changes with the ladder of turn resistance.  If the displacement sensor is used as the feedback element of displacement in the servo system , the big unit step voltage will cause system oscillation. So in the production process of the potentiometer,the resistance of each circle should be reduced . Another major shortcoming of potentiometer is that it is easy to wear. Its advantages are: simple structure,the big output signal, easy to use, cheap price. 

　　Magnetostrictive position sensor can detect the absolute position of moving magnet accurately through the non-contact measurement and control technology and then measure the actual displacement of the products to be tested .The high precision and reliability of sensors have been widely applied in tens of thousands of actual cases. 

　　Due to the activities of the position for the determination of graviation and sensitive components and no direct contact, therefore sensor can be used in a very bad industrial environment, not easy be oily be soiled, solution, dust or other pollution and IP protection grade in IP67 above. In addition, the sensor used high-tech materials and advanced electronic processing technology, so it can be used in high temperature, high pressure and high oscillation of the environment. Sensor output signal for absolute displacement value, even if power supply, heavy meet, the data will not lose, no more to be zero. Due to the sensitive components are contact, even if repeating the detection, also won't cause any wear of sensor, can greatly increase the reliability of the test and service life. 

　　Magnetostrictive position sensor, is to use magnetostrictive principle, through two different magnetic field fellowship produce a strain pulse signal to accurately measure the position. The measuring element is a root wave guide, waveguide tube of sensitive components by special magnetostrictive material is made. The measurement process by the sensor is electronic indoor generation current pulse, the current pulse in waveguide tube transmission, and thus to the wave produces a circumference of magnetic field, when the magnetic field and in a wave of as's change of position of graviation activities magnetic fields produced intersect, because the magnetostrictive effect, the waveguide tube will produce a strain wave pulse signal, the strain wave with a fixed voice of the pulse signal transmission speed, and was quickly electronic room are detected. Due to the strain wave in the waveguide tube pulse signal transmission time and activities with the electronic chamber of graviation and the distance between the direct proportion, through the measurement of time, it can be highly precisely determine the this distance. Due to the output signal is a real absolute value, not the proportion of the signal processing or scaling, so nonexistent signal drift or change in the value of the situation, the more without regular heavy standard. 

　　Magnetostrictive position sensor is based on magnetostrictive principle of high precision, long trip made absolute position measurement of the displacement sensor. It USES contactless measurement methods, because they can used for measuring activities and sensor itself and no direct contact with, and not be friction and wear, so its long service life, environment adaptable, high reliability, good safety, facilitate system automation work, even in bad industrial environment, also can work normally. In addition, it also can bear high temperature and high pressure and strong vibration, have been widely used in mechanical displacement measurement and control.