Dual Sensor (Pirani and Piezo) Vacuum Sensors

HPM-2002 Dual Sensor Vacuum Gauge

HPM-2002 Dual Sensor Vacuum Gauge

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 1×10-4 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 1×10-4 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.

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 Au plated Kovar header.

This header is welded into the stainless tube shell and will withstand positive pressures of over 150 psi. Note: Calibration is stored within tube memory chip. Each Model 2002 transducer contains within a programmable memory chip (EEPROM). Stored on the EEPROM are the calibration parameters for both the thin film Pirani and the piezoresistive bridge. Also contained on the EEPROM is identification information which is suitable for use in quality programs.

FEATURES

• Combined Pirani and Piezoresistive Sensors in a Single Tube
• Wide Dynamic Range: 1000 Torr to 1×10-4 Torr
• Automatic Crossover
• Calibration
• Attitude Insensitive – Can Be Mounted in Any Orientation
• Fast Dynamic Response Time
• Compact Rugged Design
• Withstand 150 PSIG Positive Pressure
• Linear Per Decade Output Signal
• Custom Outputs Available

APPLICATIONS

• Wide Range Vacuum Applications
• Process Control and Test
• Ultra-Fast Response
• General Vacuum Control
• Vacuum Furnace Control
• Loadlock System
• Transformer “DeGAS” System
• Sputtering Chambers