Chilled Mirror Optical Hygrometers

the ultimate standard inmoisture measurement

technology

The Ultimate Standard in Moist:

Product ScopeKahn offers two optical (chilled mirror) hygrometer products, Optidew and Series 4000, to meet therequirements of a broad range of dewpoint measurement applications. Each product is available in a varietyof models to suit the user’s specific needs. Kahn’s 20 years of experience in chilled mirror technology hasproduced extremely sensitive (part per billion), accurate and drift-free instrumentation for measurement of gasdewpoint. All Kahn hygrometers offer measurement traceability to national and international standards.

OPTIDEWCompact, Economical & Rugged

SERIES 4000 Ultimate in Dewpoint Monitoring

Principle of OperationKahn optical hygrometers use a fundamentaland therefore highly accurate and reliablemethod of continuously measuring the dew-point of a gas sample. A mirror is chilled by aPeltier thermoelectric heat pump; a light isfocused on the mirror; a photodetector meas-ures the amount of light being reflected or scat-tered off the mirror; a platinum resistance ther-mometer (PRT) measures the temperature ofthe mirror which is dewpoint or frostpoint, bydefinition.

Mirror and Cooling SystemA chemically resistant, polished metal mirror isthermally bonded to a multi-stage Peltier ther-moelectric heat pump. Direct current deliveredto the heat pump allows the mirror to cool untilcondensation begins to form.

Electro-Optical Detection SystemA single (Optidew) or dual (Series 4000) opticaldetection system consisting of a light sourceand photodetector(s) measures reflected and/orscattered light off the mirror. Closed-loop tem-perature control ensures rapid equilibriumbetween condensation and evaporation at themirror surface.

Temperature Measurement SystemThe temperature of the mirror surface is meas-ured directly with a highly accurate 100W PRTembedded within the mirror, and is displayed inselectable units on the instrument’s front panel.

Contamination CompensationContamination can compromise the measure-ment accuracy of a optical hygrometer. All Kahnoptical hygrometer products feature eitherDynamic Contamination Correction (DCC) orAutomatic Balance Compensation (ABC), whichensures continuous optimal operation of thesensor in contaminated environments. Thecontamination compensation system periodi-cally heats the mirror to vaporize the accumu-lated dew or frost. The instrument then read-justs itself to allow for altered reflectivity due tocontaminants and returns to normal measuring.

NOTE: The information included herein was correct at the time ofpublication and supercedes all previous data. It is our policy to con-tinually improve our products to insure even better performance.Consequently current Kahn products may incorporate modificationsnot shown on these pages.

SampleIn

Light SourceReflected LightDetector

Peltier Heat Pump

SampleOut

Mirrorand PRT

ScatteredLightDetector

ViewingPort

The Optidew Dewpoint and RH Hygrometer is a com-pact, sturdy and economical instrument that providescontinuous dewpoint measurement, display and output.Key features include:

*The S4000RS and S4000TRS also feature our unique “speed pipe” technology that improves the response speed at trace moisture levels. The “speed pipe”concentrates the formation of ice crystals on the mirror surface and can reduce response time at trace moisture levels by a factor of four times.

ModelsOptidew-Wall

� Wall mount transmitter with integral sensors

Optidew-Remote� Transmitter with remote sensors and 6 foot cables

Optidew-Probe� Transmitter with probe type sensor

Optidew-Bench� Bench mount hygrometer with monitor, carry

handle, remote sensors and 6 foot sensor cables

ModelsS4000 Integrale

� Lightweight with measurement range to -60°C� Dual display: °F or °C dewpoint and PPM or %RH

S4000 Remote� Remote sensor in a compact housing� Climatic version: dewpoints to +85°C

S4000RS*� Temperature-controlled sensor body for dewpoint

measurements to -85°C (230 ppb)

S4000TRS*� Temperature-controlled sensor body for dewpoint

measurements to -100°C (13 ppb)

The Series 4000 Hygrometer family features the most accurate and versatile optical hygrometersavailable in the marketplace today. Key features include:

Series 4000� Dewpoint measurements from -100°C to +85°C

� Accuracy of ±0.1°C

� Resolution of ±0.01°C

� 3-Stage Peltier cooling

� Automatic contamination compensation

� Current, voltage and RS232 digital outputs

� Dual optics detection system

� Precision platinum resistance thermometer

� Microscope to monitor condensation on mirror

� Optional pressure compensation

� Built-in data hold function

Optidew� -60 to +115°C dewpoint measurement range� Accuracy of ±0.2°C� 1-Stage or 2-Stage Peltier cooling� Automatic contamination compensation� Built-in data hold function� Analog and digital outputs� Transmitter or display models� High temperature sensor available

Some SatisfiedCustomers

Air ProductsCargillDuke EnergyExxonMobilFord General ElectricHarvard UniversityHoneywellIBMIntelLockheed MartinMerckNASANational Weather ServicePratt & Whitney AircraftQualcommTennessee Valley AuthorityTexas InstrumentsTranswestern PipelineU.S. NavyUnited Technologies

The calibrations of Kahn hygrometers are traceable to the NationalInstitute of Standards and Technology. Sensors are calibrated througha master optical hygrometer which has been calibrated at the NISTand is periodically re-calibrated. A certificate of traceability is provid-ed with all of these instruments.

Applications Count onKahn ExperienceKahn, a leader in pneumatic, hydraulic andelectronic technology for over 50 years,provides innovative solutions to practicalmeasurement problems. Since Kahn’s firstmoisture measurement designs were intro-duced 40 years ago, we have manufac-tured high quality, durable hygrometers formany specialized applications, often underdemanding conditions. Our long-standingsuccess in customer satisfaction and ourexpanding product line ensure that Kahncan provide you with hygrometers to suit allyour needs.

Kahn provides technical support and main-tenance for all of its equipment, from theearliest models to the latest innovations.Our hygrometers are also backed by thefinest warranty in the industry: One full yearon calibration and workmanship for boththe instrument and sensor.

Utility Switchgear Performance MonitoringSulfur hexaflouride (SF6) is used by electric utilities as aninsulating gas in high voltage switchgear. Because humiditycompromises the ability of SF6 to insulate, Kahn opticalhygrometers are used to monitor its dewpoint and preservethe integrity of vital utility company equipment.

Motor Vehicle Emissions TestingMeasurement of motor vehicle emissions such as nitrousoxide, carbon monoxide, lead and residual hydrocarbons isaffected by humidity. By precisely measuring dewpoint, Kahnoptical hygrometers help ensure an accurate determinationof emissions concentrations.

Calibration Reference TestingInstrument manufacturers, calibration laboratories and otherend users utilize Kahn optical hygrometers as referencestandards when verifying the calibration or performance ofrelative humidity probes or dewpoint sensors.

Electronic Component ManufacturingMoisture is an unwanted contaminant in the manufacture ofsemi-conductors, integrated circuits and other electroniccomponents. Kahn optical hygrometers are used to monitordewpoint levels in gases used in production processes and tocontrol humidity in fabrication and assembly areas.

Heat TreatingAnnealing, carburizing and other heat treat processes requireprecise monitoring and control of moisture content. Kahnoptical hygrometers allow manufacturers and independentheat treaters to control the quality of their processes, mini-mize scrap and ensure compliance with quality standardsincluding ISO 9000.

Gas Turbine Inlet Air MonitoringThe moisture content of air drawn into industrial gas turbinesmust be monitored to optimize combustion and minimizeharmful emissions. Durability and accuracy of moisturemeasurement instrumentation are essential. These benefitsare provided by Kahn optical hygrometers to turbine manu-facturers and users worldwide.

ture Measurement Technology

CHILLED MIRROR HYGROMETER SPECIFICATIONS

Optidew Optidew Optidew Optidew S4000 S4000 S4000RS S4000TRSWall Remote Probe Bench Integrale Remote

GENERALSystem Accuracy ±0.2°C* ±0.2°C* ±0.2°C* ±0.2°C* ±0.1°C ±0.1°C ±0.1°C ±0.1°C

*Optional accuracy: : ±0.15°C

Cooling Rate 1°C/Sec 1°C/Sec 1°C/Sec 1°C/Sec 0.5°C/Sec 0.5°C/Sec 0.5°C/Sec 0.5°C/Sec

Digital Display Optional Optional Optional Integrated Dual Dual Dual DualIntegrated Integrated Integrated

Units°C or °F °C, °F, %RH °C, °F, %RH °C, °F, %RH °C, °F, %RH °C, °F, PPM(V), °C, °F, PPM(V), °C, °F, PPM(V), °C, °F, PPM(V),

g/m3, g/kg g/m3, g/kg g/m3, g/kg g/m3, g/kg PPM(W), %RH, PPM(W), %RH, PPM(W), %RH, PPM(W), %RH,g/m3, g/Kg or kPa g/m3, g/Kg or kPa g/m3, g/Kg or kPa g/m3, g/Kg or kPa

4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA, 4-20 mA,0-20 mA, 0-20 mA, 0-20 mA, 0-20 mA, mV/°C mV/°C mV/°C mV/°C

Outputs RS232 RS232 RS232 RS232 RS232 RS232 RS232 RS232RS485 opt. RS485 opt. RS485 opt. RS485 opt.Alarm Relay Alarm Relay Alarm Relay Alarm Relay

Sensor Location Integral Remote Integral Remote Integral Remote Integral Integral

Configuration Wall Bench Flange Bench Bench or Bench or Bench or Bench oror panel or panel 19” rack 19” rack 19” rack 19” rack

Pressure Compensation No No No No Yes Yes Yes Yes

Power Requirements 90-264 VAC 90-264 VAC 90-264 VAC 90-264 VAC 90-264 VAC 90-264 VAC 115 VAC 115 VAC47-440 Hz 47-440 Hz 47-440 Hz 47-440 Hz 47-440 Hz 47-440 Hz 50-60 Hz 50-60 Hz

DimensionsMonitor Dimensions H x W x D 14.5”x9”x4” 9”x9”x4” 18.4”x10”x22.7” 4”x11.5”x10.3” 5.5”x19”x17” 5.25”x10.5”x8.5” 16”x19”x20” 34”x22”x24”Sensor Dimensions L x Dia. 5”x1.8” 5”x1.8” 5”x1.8” 5”x1.8” includes sensor 5.5”x19”x17” includes sensor includes sensor

(H x W x D)

Weight 7 lbs. 8 lbs. 13.5 lbs. 6.5 lbs. 21.6 lbs. Sensor 14 lbs. Sensor 71 lbs 110 lbs.Monitor 15 lbs. Monitor 15 lbs.

-50°C to +90˚C -50°C to +90˚C -50°C to +90˚C -50°C to +90˚C -60°C to +20˚C -50°C to +20˚C* -85°C to +20˚C -100°C to +20˚C (Single Stage) (Single Stage) (Single Stage) (Single Stage)

-60°C to +90˚C -60°C to +90˚C -60°C to +90˚C -60°C to +90˚C(Dual Stage) (Dual Stage) (Dual Stage) (Dual Stage)

-50°C to +115˚C -50°C to +115˚C -50°C to +115˚C -50°C to +115˚C(High Temperature) (High Temperature) (High Temperature) (High Temperature) *Climatic Version to +85°C

Operating Pressure Vacuum to Vacuum to Vacuum to Vacuum to Vacuum to Vacuum to Vacuum to Vacuum to3600 PSIG 3600 PSIG 3600 PSIG 3600 PSIG 150 PSIG 150 PSIG 150 PSIG 150 PSIG

-40°C to +90°C* -40°C to +90°C*-40°C to +90°C* -40°C to +90°C* -20°C to +50°C -30°C to +30°C** +10°C to +30°C +10°C to +30°C

-20°C to +50°C -20°C to +50°C -20°C to +50°C -20°C to +50°C -20°C to +50°C -20°C to +50°C -20°C to +50°C -20°C to +50°C*High Temperature Sensor: -40°C to +115°C **Climatic Version to +90°C

Sample Flow Rate 0.1 to 0.1 to 0.1 to 0.1 to 0.05 to 0.1 to 0.1 to 0.1 to 2 L/min. 2 L/min. 2 L/min. 2 L/min. 0.2 L/min. 0.7 L/min. 0.7 L/min. 0.7 L/min.

Catalog no. OpticalPrinted in USA 0304

885 Wells Road, Wethersfield, CT 06109 Phone: (860) 529-8643 Fax: (860) 529-1895 www.kahn.com hygros@kahn.comKAHN INSTRUMENTS, INC.

DEWPOINT SENSOR

Measurement RangeDewpoint

Operating TemperatureStandard Sensor

Electronics