Precision Chilled Mirror Hygrometer

The new S8000 Hygrometer provides a direct measurement of dew point, temperature and pressure. Dew-point measurement is based on the proven, fundamental optical chilled mirror measurement principle, giving long-term drift-free humidity measurement over the entire operating range. The S8000 uses this measurement to offer a range of available measurement units including ppmV, absolute humidity, relative humidity and ppmW.

Product Features

  • ±0.1°Cdp (±0.18°Fdp) accuracy
  • Fundamental, accurate and drift-free measurement
  • Simple configuration and operation via touch screen interface
  • Precision measurements to –60°C (–76°F) dew point
  • FAST – guaranteed frost formation below 0°C (+32°C)
  • Measure at pressures up to 2 MPa (20 barg)
  • USB, Ethernet, RS485 or RS232 connectivity
  • Datalogging to SD card or via digital comms

Technical Specification

Dew-Point Sensor Performance
Measurement Technology Chilled Mirror
Accuracy* ±0.1°Cdp
Reproducibility ±0.05°C
Measurement Range –60 to +40°Cdp (–76 to +104°Fdp)
Operating Pressure Low pressure version: 0 to 1 barg / 14.5 psig
High pressure version: 0 to 20 barg / 290 psig
Sample Flow Rate 0.1 to l Nl/min (0.2 to 2.1 scfh)
Detection System RRS Triple Detection
Remote PRT Probe (Optional)
Temperature Measurement 4 wire Pt100, 1/10 DIN class B
Measurement Accuracy ±0.1°C
Cable Length 2m (6.6’) (250m (820’) max)
Flow Sensor
Measurement Accuracy Typical ±5% uncalibrated
Measurement Range 0 to 1000 ml/min
Integrated Pressure Sensor (Optional)
Measurement Range 0 to 25 bara (0 to 377 psia)
Measurement Accuracy* 0.25% Full Scale
Measurement Unitspsia, bara, KPa or MPag
ResolutionUser-selectable to 0.001 dependant on parameter
Measurement Units°C and °F for dew point and temperature %RH, g/m3, g/kg, ppmV , ppmW (SF6), for calculated humidities
Outputs Analog 3 channels, user selectable 4-20 mA, 0-20 mA or 0-1 V
Digital Modbus RTU over USB, and optional Modbus RTU over RS232, RS485 or Modbus TCP over Ethernet
Alarm Two volt-free changeover contacts, one process alarm, one fault alarm; 1 A @ 30 V DC
HMI 5.7” LCD with touchscreen, white on blue graphics
Data Logging SD Card (512Mb supplied) and USB interface
SD Card (FAT-16) — 2Gb max. that allows 24 million logs or 560 days, logging at 2 second intervals
Environmental Conditions –20 to +40°C (–4 to +104°F)
Power Supply 85 to 264 V AC, 47/63 Hz
Power Consumption 100 V A
EMC - Class A Emissions Industrial Location Immunity Complies with EN61236:1997 (+A1/A2/A3)
Mechanical Specifications
Dimensions 187 x 440 x 343mm (7.36 x 17.32 x 13.5”) h x w x d
Weight 11.4kg (25.1lb)
Process Connections 6mm Swagelok® (MALE)
tube or 1/4” Swagelok® tube (MALE)
Storage Temperature –20 to +50°C (–40 to +122°F)
Calibration 3-point traceable in-house calibration as standard
UKAS accredited calibrations optional - please consult Michell

* Measurement accuracy means maximum deviation between instrument under test and corrected reference. To this must be added the uncertainties associated with the calibration system and the environmental conditions during testing or subsequent use.

Chilled Mirror Reference Instruments

S8000 Remote S8000 Remote
The S8000 Remote provides accurate measurement of dew-point, temperature and relative humidity and is designed for environmental monitoring.
S8000 RS S8000 RS
Our flagship chilled mirror hygrometer, capable of measuring as low as -90°C dew point in a compact, lightweight package. The sensor head is optimised for fast response to low moisture levels and features the RRS system for high sensitivity and a dew-point accuracy of ±0.1°C.

Calibration Instruments

optidew_401_501.htm Optidew
The Optidew 401 and Optidew 501 are chilled mirror hygrometers, designed as successors to the original Optidew instruments. The Optidew 401 is a bench top model, replacing the Optidew Vision. The Optidew 501 is wall mounted to replace the Optidew transmitter, but offer an option to have the same touch-screen interface as the Optidew 401 for easy local operation. There is also a transmitter version of the Optidew 501 without a display.
Premium customizable rack-mounted dew-point calibration station with chilled mirror reference.