Dew-Point Transmitters Pure Gas Moisture Transmitter This small pure gas transmitter is a rugged, self-contained hygrometer designed specifically for the measurement of trace moisture content in ultra high purity gases. Simple to use and install, the Pura is available in two-wire, three-wire and hazardous area versions and is fully configurable to meet specific needs. Measurement range down to -120°C (-184°F) dew point (1ppbV) Pure gases Stable and repeatable measurement Semiconductor manufacture Analog and digital output Fibre optic production Simple installation Electronic component manufacture Optical coating processes Optional display / alarm unit Industrial gas production and distribution Compact design Fast response Optional hazardous area approval

Dew-Point Transmitters Pure Gas Dew-Point Transmitter In many high purity gas applications, such as the semiconductor industry, the residual moisture content of the gas is critical to the satisfactory operation of a process. Historically trace moisture measurement has been problematic, demanding the use of complex moisture analysers or expensive analytical techniques. Now Michell has brought to market a simple, economical and very effective solution for on-line measurement of dew-point temperatures down to -120°C (-184°F) (equivalent to less than 1 part per billion). The Pura transmitter benefits...

Dew-Point Transmitters Sensor Technology Ceramic Impedance Sensor The Pura uses Impedance technology, based on Michell’s advanced ceramic sensor. The operation of this sensor depends on the dielectric property of water molecules absorbing onto an active porous insulating layer sandwiched between two layers of conductive material deposited on a ceramic substrate. Water has a very high dielectric compared to the dielectric of the active layer and the background of the carrier gas so it can be detected easily. The active layer is very thin – less than one micron and the porous top conductor that...

Dew-Point Transmitters Technical Specifications Monitors Sensor Sensor Type Michell Advanced Ceramic Moisture Sensor -120 to -40°Cdp (calibrated from -100 to -40°C) (-184°F to -40°Fdp calibrated from -148 to -40°F) Operating Pressure Measurement Units °F, °Cdp; ppmV and ppbV with user selectable range and resolution Simple display defined by 2-wire sensor input Secondary measurement variable Pressure via external transducer 0-30 MPa (300 variable barg/4351 psi). Completely user configurable for any industry standard transducer. Automatic compensation for ppmV and ppbV ppmV with no line pressure...