| This new range of KELLER OEM pressure transmitters and transducers offers the user the high accuracy and stability of the KELLER piezoresistive pressure capsule in a low cost OEM package. Applications include refrigeration, hydraulic controls, air compressors, ink jet printers, vacuum pumps etc. The silicon sensor is mounted in an all welded oil filled stainless steel capsule, providing a highly stable measuring cell with negligible hysteresis, unrivalled linearity, high output and a life of millions of pressure cycles. The Series 21R use the Series 6 capsule, which is of all welded 316L stainless steel construction. Transducers are supplied with 2 metres of screened cable, or a square connector and mating plug, type mPm-193. Accuracy is achieved by very large scale predictable production quantities of the pressure capsule (over 2 million produced today). Reliability is assured by the inherent properties of the perfectly elastic silicon chip, and ensuring that neither the pressure media nor the reference media (in the gauge version) come into contact with any sensitive parts. Temperature Compensation: Each unit is fully tested and compensated. Span errors are reduced by selecting the semiconductor doping levels so that the gauge factor of the strain gauges (ΔR) is constant with temperature. Thermal zero compensation is achieved by an automatic test procedure which fits a single resistor across one arm of the bridge. Shock and vibration performance is excellent due to the silicon chip being suspended in the oil-filled capsule. It is isolated mechanically from the body. Similarly, the effects of mounting torque are eliminated. | 
Pressure 
