Optidew Vision

Precision Dew-Point Meter

This product has now been replaced by our new Optidew 401 and will be withdrawn from the market on 1st July 2018. Orders will only be accepted for this model up to 30th June 2018.

The Optidew Vision precision dew-point meter is based on the proven, fundamental optical dew-point measurement principle, giving long-term drift-free performance. It offers a wide measurement range from the equivalent of <0.5 to 100% RH at ambient temperature (dew point range: -40 to +90°C (-40 to +194°F), and up to +130°C (+266°F) with high temperature option).

The Optidew is an excellent entry level calibration reference, supplied as standard with a fully traceable in-house calibration or optional UKAS-certified calibration. Its simple operation makes it possible for anyone to use with minimum training. Simply connect the instrument, power it up and measurement will begin automatically.

Product Features

  • Fundamental drift-free dew-point measurement
  • Measurement range: <0.5 to 100% RH from -40 to +90°C ambient
  • ±0.2°Cdp (±0.36°Fdp) accuracy; optional higher accuracy available
  • High temperature sensor option to +130°C (+266°F)
  • Rugged NEMA 12 bench-top housing
  • High pressure sensor option to 25 MPa (250 barg/ 3626 psig)
  • Purpose-designed climatic chamber reference sensor option
Optidew Vision

Technical Specification

Measurement Accuracy* ±0.2°Cdp (±0.36°F)
±0.15°Cdp (±0.27°Fdp) accuracy optional
±0.1°C (±0.18°Fdp) temperature
Measurement Units °C, °F dew point; %RH; °C, °F temperature; g/m3; g/kg; aW; ∆ (t-t dew point)
Response Speed 1°C/sec (1.8°F/sec) plus settling time (dew point dependant)
Power Supply 90 to 264 V AC or 127 to 370 V DC, 47 to 440 Hz, 20 W max. internally fused, 4A quick blow
Dew-Point Sensor
Sensor1 Stage2 StageHigh temperature PEEKClimatic or Aluminum head
Dew-Point Range-30°Cdp @ sensor temp of 20°C
+90°Cdp @ sensor temp of 90°C
-40°Cdp @ sensor temp of 20°C
+90°Cdp @ sensor temp of +90°C
-40°Cdp @ sensor temp of 20°C
+130°Cdp @ sensor temp of 130°C
-10°Cdp @ sensor temp of +20°C
+130°Cdp @ sensor temp of +130 °C
Temperature Range-40 to +90°C
(-40 to +194°F)
-40 to +90°C
(-40 to +194°F)
-40 to +130°C
(-40 to +266°F)
-40 to +130°C
(-40 to +266°F)
%RH Range<2 to 100%<0.5 to 100%<0.5 to 100% 10 to 100%
Min Measured Dew Point @ +20°C (+68°F)-30°C (-22°F)-40°C (-40°F)-40°C (-40°F)-10°C (+14°F)
Mirror Material Options Gold plated copper (standard)
Gold stud
316 stainless steel stud**
Platinum stud**
Sensor Body Material Options Acetal (standard)
High temperature PEEK
316 stainless steel**
Anodized aluminum**
Temperature Measurement 4 wire Pt100, 1/3 DIN class B
Sample Flow 0.1 to 2 Nl/min (0.2 to 4 scfh) (in sampling block)
Maximum Velocity 10 m/sec (32.8 f/sec) direct insertion
30 m/sec (98.4 f/sec) with sintered guard
Pressure Standard unit: 2 Mpa / 20 barg (300 psig) (max)
Ingress Protection: IP66
High Pressure version: 25 Mpa / 250 barg (3626 psig) (max)
Ingress Protection: IP65
Sensor cable Standard cable: PVC insulator material, +70°C (+158°F) max temperature
High temperature cable: Silicone insulator material, +180°C (+356°F) max temperature
Cable Length 2m (6.56'); 50m (164') up to 250m (820') on special request
Remote PRT
Temperature Measurement 4-wire Pt100 1/10 DIN class B
Sensor cable Standard cable: PVC insulator material, +70°C (+158°F) max temperature
High temperature cable: PTFE insulator material, +250°C (+482°F) max temperature
Cable Length 2m (6.56'); 50m (164') maximum up to 250m (820') on special request
Transmitter Electronics
Resolution 0.1 for °C, °F and %RH
0.01 for g/m3 and g/kg
Outputs Analog: 4–20 mA or 0–20 mA over user-settable output, Accuracy: ±0.2°C (±3.6°F); 500 Ω maximum load resistance
Digital: RS232 @ 9600 baud rate
Alarm: Volt free contact, 2 A @ 30 V DC, 0.5 @ 120 V AC
Status LEDs DCC / Alarm Status
Operating Temperature -20 to +50°C (-4 to +122°F) ambient
Environmental conditions Up to 98% RH non-condensing
Enclosure Standing case with carry handle, Panel mounting kit optional
Ingress Protection IP54 (NEMA 2)
Cable Pack Mains, RS232 cable and output connector
Calibration 4-point traceable in-house calibration as standard, UKAS accredited calibrations optional – please consult Michell Instruments
*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 and subsequent use
** Recommended for special applications only, consult Michell Instruments before ordering

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