Kahn Optidew Series User manual

Optidew
Chilled Mirror Hygrometer
User's Manual
Kahn Instruments, Inc. October 2019
This document is the property of Kahn Instruments and may not, either in part or whole, be copied or
otherwise reproduced, communicated in any way to third parties nor stored in any data processing
system, without the written authority of Kahn Instruments, Inc.

Optidew
For Kahn Instruments' contact information please go to
www.kahn.com

Optidew User’s Manual
Kahn Instruments iii
1 INTRODUCTION ................................................................................................1
1.1 Optidew Series................................................................................................... 1
1.2 Optidew Sensor.................................................................................................. 2
2 INSTALLATION ..................................................................................................3
2.1 Mounting ........................................................................................................... 3
2.2 Instrument Connections...................................................................................... 5
2.2.1 Optidew Wall Mount ...................................................................................... 5
2.2.2 Optidew Bench Top ....................................................................................... 7
2.3 Electrical Connections ......................................................................................... 9
2.3.1 Electrical Supply............................................................................................ 9
2.3.2 Analog and Digital Communications.............................................................. 10
2.3.2.1 Digital Communications ......................................................................... 10
2.3.2.2 Current Outputs.................................................................................... 11
2.3.2.3 Relay Contacts...................................................................................... 11
2.4 Sensor Installation............................................................................................ 13
2.4.1 Environmental monitoring............................................................................ 13
2.4.2 Sample flow monitoring............................................................................... 13
2.4.3 Integral Sensor mounting ............................................................................ 14
2.5 Temperature Probe Installation.......................................................................... 14
2.6 Pressure Transmitter Installation........................................................................ 14
3 USER INTERFACE ............................................................................................15
3.1 Main Display .................................................................................................... 15
3.1.1 Main Screen................................................................................................ 16
3.1.2 Customizable Readouts................................................................................ 17
3.1.2.1 Locking the Analyzer ................................................................................... 17
3.1.3 Menu Structure........................................................................................... 18
3.1.4 Operational Status Display ........................................................................... 19
3.1.5 Sensor Status Display.................................................................................. 20
3.2 Setup Menus.................................................................................................... 21
3.3 Transmitter Version........................................................................................... 29
Contents
Safety ...............................................................................................................................vii
Warnings ........................................................................................................................vii
Electrical Safety..................................................................................................................vii
Pressure Safety ..................................................................................................................vii
Calibration (Factory Validation)........................................................................................... viii
Repair and Maintenance .................................................................................................... viii
Abbreviations......................................................................................................................ix

Optidew User’s Manual
iv October 2019
3.3.1 Optics Calibration ............................................................................................. 29
4 OPERATION ....................................................................................................30
4.1 Operating Cycle................................................................................................ 30
4.2 Operating Guide ............................................................................................... 31
4.2.1 Description ................................................................................................. 31
4.2.2 Operating Practice....................................................................................... 31
4.3 Good Measurement Practice.............................................................................. 32
4.3.1 Sampling Hints............................................................................................ 32
4.3.2 First Time Operation.................................................................................... 35
4.4 Operational Functions ....................................................................................... 35
4.4.1 DCC Function.............................................................................................. 35
4.4.2 MAXCOOL Function ..................................................................................... 36
4.4.3 Frost Assurance Technology (FAST) .............................................................. 36
4.4.4 STANDBY Mode........................................................................................... 36
4.4.5 Parameter Conversions & Pressure Compensation ......................................... 37
4.4.6 Data Logging.............................................................................................. 37
4.5 Minimum Measurable Dew Points....................................................................... 37
4.6 Warnings and Faults ......................................................................................... 38
5 MAINTENANCE................................................................................................42
5.1 Mirror Cleaning................................................................................................. 42
5.2 Exchanging Sensors.......................................................................................... 43

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Kahn Instruments v
Figures
Figure 1 Optidew Wall Mount (wall mount) and Optidew Bench Top (bench top) ..........1
Figure 2 Optidew Wall Mount wall mounting points ....................................................3
Figure 3 Optidew Wall Mount display front panel .......................................................5
Figure 4 Optidew Wall Mount non-display front panel.................................................6
Figure 5 Optidew Wall Mount bottom panel ...............................................................6
Figure 6 Optidew Bench Top top panel......................................................................7
Figure 7 Optidew Bench Top left side panel ...............................................................7
Figure 8 Optidew Bench Top right side panel .............................................................8
Figure 9 Optidew Bench Top rear panel.....................................................................8
Figure 10 RS485 & analog output connector .............................................................10
Figure 11 Analog output connector...........................................................................11
Figure 12 Relay contact connector............................................................................11
Figure 13 Main screen .............................................................................................15
Figure 14 Main screen layout ...................................................................................16
Figure 15 DCC menu ...............................................................................................21
Figure 16 Logging screen.........................................................................................22
Figure 17 Outputs screen.........................................................................................23
Figure 18 Alarm screen............................................................................................24
Figure 19 Display screen..........................................................................................25
Figure 20 Clock screen ............................................................................................26
Figure 21 Inputs screen...........................................................................................27
Figure 22 Comms screen .........................................................................................28
Figure 23 Network settings screen............................................................................28
Figure 24 Typical operating cycle..............................................................................30
Figure 25 Room measurement example ....................................................................32
Figure 26 Mirror contamination warning symbol ........................................................33
Figure 27 Material permeability comparison...............................................................34
Figure 28 Formation of condensation........................................................................35
Figure 29 2-Stage minimum measurable dewpoint.....................................................40
Figure 30 System alarm...........................................................................................41
Figure 31 Mirror contamination warning....................................................................42
Figure 32 Sensor cleaning........................................................................................43

Optidew User’s Manual
vi October 2019
Appendices
Appendix A Technical Specifications..............................................................................44
Appendix B Modbus Register Map ................................................................................47
Appendix C Dimensional Drawings................................................................................56

Optidew User’s Manual
Kahn Instruments vii
Safety
The instrument is designed to be completely safe when installed and operated correctly in
accordance with the information provided in this manual.
This manual contains all the required information to install, operate and maintain this product.
Prior to installation and use of this product, this entire manual should be read and understood.
Installation and operation of this product should be carried out by suitably competent personnel
only. The installation and operation of this product must be in accordance with the instructions
provided and according to the terms of any associated safety certificates. Incorrect installation
and use of this product other than those described in this manual and other than its intended
purpose will render all warranties void.
Electricity and pressurized gas can be dangerous. This product must be installed and operated
only by suitable trained personnel.
No user serviceable parts inside
!
Warnings
!
Where this hazard warning symbol appears in the following sections,
it is used to indicate areas where potentially hazardous operations
need to be carried out and where particular attention to personal and
personnel safety must be observed.
DANGER
Electric
Shock Risk
Where this symbol appears in the following sections it is used to
indicate areas of potential risk of electric shock.
Electrical Safety
Insure electrical safety is complied with by following the directions provided here and observing all
local operation & installation requirements at the intended location of use.
This product is completely safe when using any options and accessories supplied by the manufacturer
of this product for use with it. Refer to Section 2 (Installation) of this manual for further details.
Pressure Safety
For this product to operate satisfactorily, pressurized gas must be connected to it. Observe all the
information contained within this manual and all local operation & installation requirements at the
intended location of use. Refer to Section 2 (Installation) of this manual for further details.

Optidew User’s Manual
viii October 2019
Calibration (Factory Validation)
Prior to shipment, the instrument undergoes stringent factory calibration that is traceable to national
standards. Due to the inherent stability of the instrument, regular factory calibration is not required,
however recalibration is recommended to maintain measurement traceability.
Kahn Instruments can provide a fully traceable factory calibration service for the instrument and it is
recommended that this is considered at intervals of every year of the analyzer's life. Please contact
Kahn Instruments for further details (www.kahn.com).
Repair and Maintenance
Apart from user-replaceable components required for routine operational maintenance described
above, the instrument must only be maintained either by the manufacturer or an accredited service
agent.

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Kahn Instruments ix
Abbreviations
The following abbreviations are used in this manual:
A ampere
AC alternating current
atm pressure unit (atmosphere)
bara pressure unit (=100 kP or 0.987 atm) (absolute)
barg pressure unit (=100 kP or 0.987 atm) gauge
°C degrees Celsius
°F degrees Fahrenheit
EU European Union
hr hour
Hz Hertz
IEC International Electrotechnical Commission
IP Internet protocol
ml/min milliliters per minute
mg/m3milligrams per cubic meter
lbs/MMscf pounds per million standard cubic feet
mA milliampere
mins minutes
mmHg millimeter of mercury
Pa pascal
ppmVparts per million (by volume)
ppmWparts per million (by weight)
psia pound(s) per square inch (absolute)
psig pound(s) per square inch (gauge)
RH relative humidity
RS485/232 standards defining the electrical characteristics of drivers & receivers
RTC real time clock
RTU Remote Terminal Unit
SD storage device card
UART universal asynchronous receiver/transmitter
USB Universal Serial Bus
V Volts
" Inch
Δ delta
% percentage
Ω ohms

Optidew User’s Manual
Kahn Instruments 1
INTRODUCTION
1 INTRODUCTION
The Optidew chilled mirror hygrometer is based on the proven, fundamental condensation
temperature dewpoint principle, giving unmatched long-term drift-free performance.
Kahn offers three highly durable sensor options, which are suitable for measuring in a
wide variety of different samples.
1.1 Optidew Series
The Optidew series is available in two different enclosures:
Figure 1 Optidew Wall Mount and Optidew Bench Top
The Optidew Wall Mount features a compact ABS enclosure with an aluminium base
plate and 4 external lugs for easy mounting to a panel or wall. It is available with a 5.7"
touch screen display, or as a blind "transmitter only" version.
A weatherproof version of the Optidew Wall Mount enclosure is available with a modified
connector panel to improve ingress protection to IP65/NEMA 4. Note that the Ethernet
and SD card options are not available in combination with the weatherproof version.
The Optidew Bench Top is designed to be easy to handle and transport, and is ideal for
laboratory or service use. It has a 5.7” touch screen LCD equipped as standard.