Piezoresistive silicone pressure is a common sensing principle for micromachined sensors. Honeywell Sesniing and Control is equipped with four piezoresistors buried in a chemically- etched silicon diaphragm. This diaphragm is being flexed together with the buried resistors whenever there is a change in pressure that induces stress. It results to an electrical output when the resistor value changes in proportion to the stress applied. Because these sensors are small, they are more reliable and cheap. They feature maximum repeatability, precision and reliability under different conditions. also, they are highly consistent with regard to operating characteristics and interchanges without recalibration. They are best used for medical and HVAC devices, dt=ata storage and gas chromatography.