HPM 2002

The Model 2002, Dual Sensor Vacuum Gauge, is a wide range vacuum instrument consisting of a digital microprocessor- based display unit, two sensing elements (micro- Pirani and piezoresistive bridge) in a single tube shell, and an interconnecting cable. Together, these components provide accurate vacuum measurement over 7 decades of pressure from 1x10-4 Torr to 1000 Torr. This instrument is a new design approach based on over 60 years of experience by Teledyne Hastings Instruments (THI) with well-known pressure measurement techniques. A single tube contains both a THI patented thin film Pirani sensor and a piezoresistive sensor in a small, rugged and inexpensive package. The piezoresistive bridge is a direct force sensor which gives very accurate readings at high pressures from atmosphere down to less than 1 Torr without the concerns of gas composition. The thin film Pirani measures pressures from a few Torr down to 1x10-4 Torr. An algorithm residing in the microprocessor ensures a seamless transition between sensors. Additionally, the two sensor outputs are used in a cross calibration mode to give even higher accuracy. New Sensor Design The Model 2002 sensors are mounted in a rugged corrosive resistant 316 stainless steel tube. The small packaging reduces the sensor’s internal volume, significantly improving response time. The tube can be mounted in any orientation with no effect on calibration and is far more rugged than standard fragile convection driven Pirani tubes. The two sensors reside on a single gold plated Kovar header