925 Micro Pirani

Vacuum Pressure Transducers

Key features

  • Absolute measurement range from 10-5 Torr to Atmosphere
  • MicroPirani sensor is resistant to damage from air inrush or vibration
  • Analog, RS232, RS485, & EtherCAT® versions
  • Optional integrated touch-screen display available for local pressure indication
  • Three optional set point relays for process control

Micro Pirani™ Sensor Technology

The 925 Transducer offers a wide measurement range from 1×10-5 Torr to atmosphere that is based on measurement of thermal conductivity. 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.

Common Gas Calibrations

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. Calibration gases include: Air, Argon, Helium, Nitrogen, Hydrogen, H2O vapor, CO2, Xenon, and Neon.

Analog Pressure Output

The 925 also has a analog pressure output of 1VDC/decade that can be interfaced to external analog equipment for pressure readout or controlling. Other analog outputs and curves can be selected via the digital user interface.

Process Control Relays

The 925 has up to three mechanical relays which can be used for process control, examples are interlocking valves or pumps.

Optional Integrated Touch-screen Display

The optional integrated touch-screen display is user configurable; the user can change pressure units, orientation and has access to set point parameters as well as gas type. The display also indicates the status of the available set point relays. Displayed pressure reading from individual sensors or combined reading can be seen from >5 meters away on the high contrast display.

PDR900 Power Supply & Display

The PDR900 power supply and readout unit is a stand alone, single channel controller for use with the Series 900 digital vacuum transducers. It can be used as a stand-alone power supply readout unit or as a tool for configuration, calibration and diagnostics of system integrated transducers in OEM applications.

KRISTIAN FLODSTRÖM Product specialist Vacuum technology 010-155 03 11