Introduction; Features - Michell Instruments Pura User Manual

Pura Advanced Online Hygrometer User Manual
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INTRODUCTION

The Pura Advanced Online Hygrometer is an instrument designed for the continuous
online measurement of moisture content in non-corrosive gases, over an operational
range of -120 °C...-40 °C (-184 °F...-40 °F) dew point and equivalent units (see Appendix
A, Technical Specifications).
The system comprises a programmable monitor configured to accept a unique Michell
Mnet data string from the Pura transmitter. The zero and span of the monitor are
set to cover the dew-point range -120 °C...-40 °Cdp (-184 °F...-40 °Fdp) at operating
pressures up to 24 MPa (240 barg/3480 psig).
Two alarm outputs are provided for connection to external systems which are user-
configurable both in terms of setpoint and operating mode. Current output is standard
and factory set at 4...20 mA (or optionally set at 0...20 mA or 0...10 V).
The monitor has a pressure input channel for any industry standard 2-wire pressure
transmitter. In addition to providing a pressure measurement, the pressure signal can
be used to provide real-time pressure compensation on the primary channel when
displaying ppm values. The customer can also set a fixed pressure compensation value.
The pressure input only affects the ppm
value is a pressure dew point.
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Features

The Pura Advanced Online Hygrometer is simple to use and install, and can be configured
to meet specific needs.
• ¼" male VCR process connections for PRM and OEM version
½" male VCR process connection for Pura SEN version
• Dew-point, ppm
• Michell Mnet – sensor digital string signal
• Sensor block compliant with clean room standards
• Measurement range -120 °C...-40 °Cdp (-184 °F...-40 °Fdp)
• Up to ±1 °Cdp accuracy
• Calibration certificate (NPL, NIST)
Michell Instruments
or ppb
V
or ppb moisture content
V V
INTRODUCTION
units. For dew point, the displayed
V
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