Vacuum Pressure Transducer, MicroPirani, 0.125 in. NPT-F, RS232, DB15, 3 Relays

The 925-31030 Micro Pirani™ Vacuum Transducer with MEMS-based Micro Pirani™ Vacuum Sensor is a thermal conductivity vacuum gauge based on a unique, MEMS-based (Micro-Electro-Mechanical Systems) vacuum sensor. This 925 transducer offers a wide measurement range from 1x10-5 Torr to atmosphere, and features a 1/8 inch female NPT fitting. It has a RS232 digital communication interface for setup of transducer parameters and to provide real time pressure measurement. A 15-pin HD sub-D male connector features an analog pressure output of 1VDC/decade that can be interfaced to external analog equipment for pressure readout or controlling and three mechanical relays which can be used for process control, examples are interlocking valves or pumps. The MicroPirani sensor consists of a silicon chip with a heated resistive element forming one surface of a cavity. A cover on top of the chip forms the other surface of the cavity. Due to the geometry of the sensor, convection cannot take place within the cavity and consequently, the sensor is insensitive to the mounting position. Gas molecules are passed by diffusion only to the heated element where the heat loss of the gas is measured. Like all thermal conductivity sensors, the 925 is sensitive to gas type. To compensate for gas dependency, the MicroPirani has a number of common gas calibrations that can be selected via the digital interface. This makes it a simple solution for locating medium to fine leaks in vacuum systems. The 925 compact design significantly reduces the amount of space occupied by a vacuum gauge. This is particularly appealing to system designers and allows for a more compact vacuum system.