Transmitters of pressesure for the control of processes
The sensors of thin film are based in the same principle that the galgas extensiométricas, that are structures of rejillas conductive that change his resistance in function of the variations of expansion or thickness induced by the change of pressesure. For a sensor of thin film place four resistances in a membrane that form in his group the bridge of Wheatstone to detect the degree of deformation in the membrane under pressesure. The galgas extensiométricas are placed and structured on a metallic element
The sensors of thick film use also four resistores forming in his group a bridge of Wheatstone. The structure prints ‘' on a basic element (for example ceramic) and afterwards incrustado with high temperature. The rank of the variation of the resistance depends also to the degree of the deformation of the membrane induced by the pressesure.
Finally, in the case of the sensors piezoresistivos applies a membrane of a material semiconductor (silicious) with structures selectivamente distributed. The operation of the sensors is based in the effect piezoresisitivo that consists in a variation of the resistance in the semiconductor, caused by his expansion and compressesion that influences in the mobility of the electrodes under mechanical load.
Wika Applies for his transmitters of pressesure these three more common principles, developed in the laboratories of his centres of investigation and manufactured in his own installations.
The reliability of these transmitters is checked in the practice. Besides they have of potentiometers to realise the adjust. In the following link can follow a video tutorial:
