Optidew

Optical Dew-Point Transmitter

This product has now been replaced by our new Optidew 501 and will be withdrawn from the market on 1st July 2018.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 precision optical dew-point transmitter 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, and up to +130°C with high temperature option).

The Optidew is ideal for industrial applications and is supplied in a rugged NEMA 4X (IP66) stainless steel wall mount enclosure. The transmitter provides two linear 0/4-20 mA outputs and RS232 serial communications, allowing configuration and monitoring by a suitable computer or PLC system or via specific Optidew logging software. An adjustable isolated alarm contact allows Optidew to be used for direct process control.

Product Features

Precision process dew point, %RH and temperature measurement
Measurement Range: <0.5 to 100% RH, -40 to +90°Cdp
±0.2°Cdp accuracy (±0.15°C optional)
Fundamental drift free dew-point measurement
Rugged NEMA 4X industrial housing
High temperature sensor option to +130°C
Optional local display

Technical Specification

Performance
Measurement Accuracy*	±0.2°Cdp ±0.15°Cdp accuracy optional ±0.1°C temperature
Measurement Units	°C, °F dew point; %RH; °C, °F temperature; g/m³; g/kg; a_W; ∆ (t-t dew point)
Response Speed	1°C/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
Sensor	1 Stage	2 Stage	High Temperature PEEK	Climatic or Aluminium head
Dew-Point Range	-30°Cdp @ sensor temperature of 20°C +90°Cdp @ sensor temperature of 90°C	-40°Cdp @ sensor temperature of 20°C +90°Cdp @ sensor temperature of 90°C	-40°Cdp @ sensor temperature of 20°C +130°Cdp @ sensor temperature of 130°C	-10°Cdp @ sensor temperature of 20°C +130°Cdp @ sensor temperature of 130°C
Temperature Range	-40 to +90°C	-40 to +90°C	-40 to +130°C	-40 to +130°C
%RH Range	<2 to 100%	<0.5 to 100%	<0.5 to 100%	10 to 100%
Min Measured Dew Point @ 20°C	-30°C	-40°C	-40°C	-10°C
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 (in sampling block)
Maximum Velocity	10 m/sec direct insertion 30 m/sec with sintered guard
Pressure	Standard unit: 2 Mpa / 20 barg (max) Ingress Protection: IP66 High Pressure version: 25 Mpa / 250 barg (max) Ingress Protection: IP65
Sensor Cable	Standard Cable: PVC insulator material, +70°C max temperature High Temperature Cable: Silicone insulator material, +180°C max temperature
Cable Length	2m; 50m maximum (up to 250m on special request
Remote PRT
Temperature Measurement	4-wire Pt100 1/10 DIN class B
Remote PRT Cable	Standard Cable: PVC insulator material, +70°C max temperature High Temperature Cable: PTFE insulator material, +250°C max temperature
Cable Length	2m; 50m maximum (up to 250m on special request
Transmitter Electronics
Resolution	0.1 for °C, °F and %RH 0.01 for g/m³ and g/kg
Outputs	Analog: Two channels 0/4-20 mA Digital: RS232 (RS485 optional) Alarm: Volt free contact, 2 A @ 30 V DC
Status LEDs	DCC / Alarm Status
Operating Temperature	-20 to +50°C ambient
Environmental Conditions	Up to 98% RH non-condensing
Enclosure	304 stainless steel
Ingress Protection	IP66 (NEMA 4X)
Cable Pack	Power and RS232 cables
General
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

Applications

Chilled Mirror Reference Instruments

S8000 Remote
The S8000 Remote provides accurate measurement of dew-point, temperature and relative humidity and is designed for environmental monitoring.

Optidew Vision
The Optidew Vision is an excellent entry-level calibration reference. It comes with all the same features as the standard Optidew.

S8000 Integrale
The S8000 Integrale is a high precision cooled mirror dew point hygrometer, suitable for a range of calibration applications.

S4000 Remote
The S4000 RC provides accurate measurement of dew-point, temperature and % RH from -85°C to +80°C dew point. The remote sensor is ideal for environmental monitoring.

S4000 TRS
The S4000 TRS is Michell Instruments' industry proven chilled mirror reference hygrometer providing accurate measurement of dew point to -100°C.

Calibration Instruments

HG10
The HG10 is an automatic temperature and humidity calibration system with a wide humidity generation range.

HG1
The HG1 is a low-cost, transportable calibrator for dew-point and relative humidity sensors with built in cooled mirror reference.

OptiCal
The OptiCal is a premium transportable calibration solution for humidity sensors with built in cooled mirror reference.

DCS
The DCS system is a premium customisable rack-mounted dew-point calibration station with cooled mirror reference.

Dew-Point Generators
A range of dew-point generators offering ease of use and fast response to humidity step changes.

Pressure Swing Dryers
A source of very dry compressed air for use as a zero gas in humidity calibration systems, or for general laboratory applications.

Oxygen and Binary Gas Analyzers

XTC601 Binary Gas Analyzer
A robust, linear and stable thermal conductivity analyzer for measurement of binary gas mixes such as air in hydrogen, nitrogen, argon, helium or carbon-dioxide.