The basic design of these devices,

The basic design of these devices, also called Capacitance Manometers, is simple and rugged and it includes a “reference cavity” that is fundamental for their proper functioning and whose pressure must be kept constant in the 106mbar scale for all the required life (minimum 10 years). This target can be achieved only thanks to the use of proper non-evaporable getters, that are typically mounted in suitable “getter chambers” in appendage to the device. SAES St172 sintered porous non-evaporable getters in cylindrical shapes without internal heaters have proved to be the most appropriate getters to guarantee the required life to pressure transducers. In fact these getters, activable at moderate temperatures, become active during the bakeout process typically performed at 250-300° C for 24-48 hours, thus making optional an activation process by direct heating before the final pinch off.