In the manufacturing operation of pressure sensors, autofrettage denotes the procedure of active ?overload? by subjecting the pressure sensor selectively once or many times to a pressure above the nominal pressure range. This technique is applied, to experience maximum stability, in particular of the zero point, in later operation. Assuming pressure gauge of the sensor, autofrettage enables a long time of trouble-free operation of the sensors even at high load cycles achieving the specified overload range, without resulting in zero-point shift or similar effects.
In digital pressure gauge , certain local regions of the sensor, where through the selective overload the yield point of the sensor material is locally exceeded, become plasticised, producing a permanent change of the instrumentation characteristics. ไดอะแฟรม ซีล on the structural conditions by way of autofrettage can be an integral the main development of the sensor and of the associated manufacturing process. Which pressure the sensor is put through and how often, must be determined individually for every sensor design by means of a complicated FEM simulation and extensive test series.
Caution ? no experiments of your! However, it must not be figured every sensor will automatically reap the benefits of subjecting it to autofrettage. Autofrettage can only just be utilized for ductile materials, but under no circumstances for brittle ones. Conditioning should be scheduled and completed very selectively sufficient reason for great care during the production stages. Ill-considered ?overpressurising? of pressure sensors by laymen who like experimenting will not only damage the sensor permanently, but also bring about dangerous preliminary damage and subsequently possibly in accidents caused by fatigue and bursting of the sensor. In this manner, an improvement in instrumentation is only going to be achieved, if, by hit or miss.