Michell Instruments OptiCal User manual

OptiCal
Humidity and Temperature Calibrator
User’s Manual
Data Acquisition
Desiccant Charge
Humidity = Yellow
De-Humidify - Green
Heating = Yellow
Cooling = Green
Chamber Set
Humidity
Display Control Chamber Set
Temperature
%rh °C
Auto On On Auto
Man. Off Off Man.
OPTI-CAL
integrated Humidity Calibrator
Max.
Min.
495 206
97079 Issue 9.2
March 2016

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© 2016 Michell Instruments
This document is the property of Michell Instruments Ltd. and may not be copied or
otherwise reproduced, communicated in any way to third parties, nor stored in any Data
Processing System without the express written authorization of Michell Instruments Ltd.
OptiCal
For Michell Instruments' contact information please go to
www.michell.com

OptiCal User’s Manual
iv 97079 Issue 9.2, March 2016
Contents
Safety ................................................................................................................................vi
Electrical Safety ...........................................................................................................vi
Toxic Materials .............................................................................................................vi
Repair and Maintenance ...............................................................................................vi
Calibration...................................................................................................................vi
Safety Conformity ........................................................................................................vi
Abbreviations.....................................................................................................................vii
Warnings ........................................................................................................................... vii
1 INTRODUCTION ................................................................................................1
1.1 Description ........................................................................................................ 1
1.2 System Components ........................................................................................... 2
1.2.1 Front Panel................................................................................................... 2
2 INSTALLATION ..................................................................................................4
2.1 Installing the Relative Humidity and Temperature Control Probes ........................... 4
2.2 Filling the Water Reservoir .................................................................................. 6
2.3 Draining the Water Reservoir............................................................................... 7
2.4 Desiccant .......................................................................................................... 8
2.5 Power Supply ..................................................................................................... 9
3 OPERATION ....................................................................................................10
3.1 Preparation ...................................................................................................... 10
3.1.1 Installing Relative Humidity Instruments for Calibration ................................. 10
3.2 Start-Up........................................................................................................... 11
3.3 Local Control of Chamber Temperature and Humidity Set Points........................... 11
3.4 Remote Control of Chamber Temperature and Humidity Set Points....................... 12
3.4.1 Digital Communications ............................................................................... 12
3.4.2 Putting the Optidew in Remote Mode............................................................ 13
3.4.3 Remote Control - Manual Set Point Control ................................................... 13
3.4.4 Remote Control - Automatic Set Point Control ............................................... 13
3.5 Typical Response Times for Various Step Changes............................................... 14
3.6 Control Outputs................................................................................................ 15
4 OPTIDEW REFERENCE INSTRUMENT ................................................................16
4.1 Optidew Display ............................................................................................... 16
4.1.1 Selecting Which ‘Screen’ to View on the Display ............................................ 16
4.1.2 Description of Screens 1- 8 .......................................................................... 17
4.2 Maintenance .................................................................................................... 19
4.2.1 Removing the Chilled Mirror Reference Sensor for Mirror Cleaning .................. 19
4.2.2 Sensor Mirror Cleaning ................................................................................ 20
4.2.3 Resetting the Mirror Condition...................................................................... 21
4.2.4 Re-calibration of the Chilled Mirror Reference................................................ 22
5 APPLICATION SOFTWARE ................................................................................23
5.1 Virtual Hygrometer ........................................................................................... 23
5.2 OptiCal Remote Chamber Control ...................................................................... 24
5.3 Parameter Setup .............................................................................................. 24
5.4 Charting and Logging ....................................................................................... 26
5.5 Statistics.......................................................................................................... 28
5.6 Control Parameters........................................................................................... 28
5.7 Calibration Correction ....................................................................................... 29
5.8 Change of Password ......................................................................................... 31
6 TROUBLESHOOTING........................................................................................32

OptiCal User’s Manual
Michell Instruments v
Figures
Figure 1 OptiCal - Front View ...................................................................................2
Figure 2 OptiCal - Back Panel ...................................................................................3
Figure 3 Probe Installation .......................................................................................4
Figure 4 Location of Probes Inside the Climate Chamber ............................................5
Figure 5 Filling the Water Reservoir ..........................................................................6
Figure 6 Emptying the Water Reservoir .....................................................................7
Figure 7 Desiccant Replacement...............................................................................8
Figure 8 Level of Silica Gel Required .........................................................................8
Figure 9 Probe Ports ..............................................................................................10
Figure 10 Port Adapter Removal Tool ........................................................................10
Figure 11 Port Adapters and Removal Tool ................................................................10
Figure 12 Humidity and Temperature Setting Switches ...............................................11
Figure 13 Humidity and Temperature Setting Switches ...............................................12
Figure 14 OptiCal Manual Control .............................................................................13
Figure 15 OptiCal Programming................................................................................13
Figure 16 Optidew Chilled Mirror Reference Display and Navigation ............................18
Figure 17 Lid Screw Locations ..................................................................................19
Figure 18 Sensor Mirror Cleaning..............................................................................20
Figure 19 Potentiometer Location .............................................................................21
Figure 20 Virtual Hygrometer Window ......................................................................23
Figure 21 Parameter Setup Window..........................................................................24
Figure 22 Chart/Log Control Panel Window ...............................................................26
Figure 23 Chart Window ..........................................................................................27
Figure 24 Basic Statistics Window.............................................................................28
Figure 25 Extracts From Calibration Certificates .........................................................29
Figure 26 Calibration Correction Window...................................................................31
Figure 27 Change Password Window ........................................................................31
Tables
Table 1 Typical Response Times for Step Changes ................................................... 14
Appendices
Appendix A Technical Specifications.............................................................................. 34
Appendix B EU Declaration of Conformity...................................................................... 36
Appendix C Quality, Recycling & Warranty Information................................................... 38
C.1 Pressure Equipment Directive (PED) 97/23/EC ............................... 38
C.2 Recycling Policy .......................................................................... 38
C.3 WEEE Compliance........................................................................ 38
C.4 RoHS2 Compliance ...................................................................... 39
C.5 Warranty..................................................................................... 39
C.6 REACH Compliance ...................................................................... 40
C.7 Calibration Facilities ..................................................................... 40
C.8 Return Policy ............................................................................... 41
C.9 Manufacturing Quality .................................................................. 41
Appendix D Return Document & Decontamination Declaration........................................ 43

OptiCal User’s Manual
vi 97079 Issue 9.2, March 2016
Safety
The manufacturer has designed this equipment to be safe when operated using the procedures
detailed in this manual. The user must not use this equipment for any other purpose than that
stated. Do not apply values greater than the maximum value stated.
This manual contains operating and safety instructions, which must be followed to ensure the safe
operation and to maintain the equipment in a safe condition. The safety instructions are either
warnings or cautions issued to protect the user and the equipment from injury or damage. Use
qualified personnel and good engineering practice for all procedures in this manual.
Electrical Safety
The instrument is designed to be completely safe when used with options and accessories supplied
by the manufacturer for use with the instrument. The input power supply voltage is 85 to 264 V AC,
47/63 Hz.
Toxic Materials
The use of hazardous materials in the construction of this instrument has been minimized. During
normal operation it is not possible for the user to come into contact with any hazardous substance
which might be employed in the construction of the instrument. Care should, however, be exercised
during maintenance and the disposal of certain parts.
Repair and Maintenance
The instrument must be maintained either by the manufacturer or an accredited service agent. Refer
to www.michell.com for details of Michell Instruments’ worldwide offices contact information.
Calibration
The OptiCal contains a high precision Optidew chilled mirror hygrometer. In order to maintain full
traceability the complete OptiCal instrument should be returned annually for a service and calibration
to the manufacturer, Michell Instruments, or one of their accredited service agents.
Safety Conformity
This product meets the essential protection requirements of the relevant EU directives. Further
details of applied standards may be found in Appendix A, Technical Specifications.

OptiCal User’s Manual
Michell Instruments vii
Abbreviations
The following abbreviations are used in this manual:
°C degrees Celsius
°F degrees Fahrenheit
AC alternating current
DC direct current
cm3cubic centimeters
gkg-1 grams per kilogram
gm-3 grams per cubic meter
Hz Hertz
in inch(es)
in3cubic inches
kg kilogram
lbs pounds
mA milli Ampere
max maximum
min minimum
mm millimeter
N/C normally closed
N/O normally open
% percentage
RH relative humidity
RS232 serial data transmission standard
T temperature
USB Universal Serial Bus
V Volts
Warnings
The following general warning listed below is applicable to this instrument. It is repeated
in the text in the appropriate locations.
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.

OptiCal User’s Manual
Michell Instruments 1
INTRODUCTION
1 INTRODUCTION
1.1 Description
The Michell OptiCal is a stable and accurate calibration solution for humidity sensors
over the 10 to 90%RH and +10 to +50°C (+50 to +122°F) range. The stand-alone,
transportable calibrator requires no external services other than mains power, and
features an integrated chilled mirror reference instrument to enable the operator to
perform calibrations that are traceable to national standards.
The calibration chamber features five interchangeable ports to accommodate virtually
any brand, type or model of sensor. The environment within the insulated calibration
chamber is temperature controlled using a four-zone fan-assisted peltier arrangement
for maximum stability and minimum temperature gradient. The humidity of the
circulating air is precisely regulated using a closed-loop control system that functions
by proportionally mixing flows of dry and saturated air.
A bright and clear VFD (vacuum fluorescent display) displays the parameters measured
by the reference instrument in various relative and absolute humidity units, alongside
the temperature within the chamber.
The humidity and temperature set-points can be controlled either manually or
automatically as part of a calibration program. Manual control is achieved by the switches
on the front panel. Response time to a humidity or temperature step change is typically
quicker than ten minutes. The supplied application software allows calibration programs
to be created, enabling automatic time-based control of temperature and humidity set
points. The software also allows the user to monitor, chart and log calibration reference
data on a PC for later analysis.
The desiccant changes color to indicate when it needs to be recharged, and is visible
through a clear window on the front of the unit. Recharge the desiccant following the
instructions in Section 2.4. The water reservoir at the front of the unit shows the current
saturator fill level, and makes it easy to top up with distilled water when required (refer
to Section 2.2). Apart from periodic calibration of the chilled mirror reference, no other
maintenance is necessary. The only external service required is a single phase power
supply.

OptiCal User’s Manual
297079 Issue 9.2, March 2016
INTRODUCTION
1.2 System Components
1.2.1 Front Panel
Data Acquisition Control Outputs
Desiccant Charge
Humidity = Yellow
De-Humidify - Green
Heating = Yellow
Cooling = Green
1 2 643 8
9
10
12
h
h
11
h
h
h
h
h
h
h
h
Max.
Min.
7
h
h
A A
B B
OPTI-CAL
integrated Humidity Calibrator
Chamber Set
Humidity
Display Control Chamber Set
Temperature
%rh °C
Auto On On Auto
Man. Off Off Man.
495 206
5
h
Figure 1 OptiCal - Front View
1. Chamber door
2. Water reservoir
3. Optidew chilled mirror reference VFD display
4. Desiccant cell and indicator window
5. Display control
6. Relative humidity set point (%RH)
7. AManual/auto switches for relative humidity / temperature control
MAN - Front panel switches control relative humidity / temperature set
points
AUTO - Remote RS232 / OptiSoft controls relative humidity / temperature
set points (see Section 3.4)
BON/OFF switches for relative humidity / temperature control
8. Temperature set-point (°C)
9. Humidity control indication LED
Humidify (yellow)
De-humidify (green)
10. 4-Zone chamber temperature control indication LEDs
Heating (yellow)
Cooling (green)
11. Control outputs
12. RS232 digital communications connector

OptiCal User’s Manual
Michell Instruments 3
INTRODUCTION
Back Panel
3
1
h
h
h
4
Remote Communications
Optics Adjustment
On
Off
h
2
h
Figure 2 OptiCal - Back Panel
1. Remote Communications Switch to enable remote chamber control
2. Optidew chilled mirror reference optics adjustment potentiometer (refer
to Section 4.2)
3. Ventilation fans
4. Electrical mains connector, on/off switch and power input fuse
Accessories
The OptiCal humidity and temperature generator is delivered with the following standard
accessories:
• Bottle of distilled water
• Desiccant cell filled with indicating silica gel
• HT961T00 control probe + temperature probe
• Chamber door (according to customer specification)
• IEC mains cord set
• Calibration certificate for internal reference probe
• Certificate of conformity (graph)
• User’s manual
• RS232 cable
• Application software
• Calibration certificate for Optidew chilled mirror reference instrument

OptiCal User’s Manual
497079 Issue 9.2, March 2016
INSTALLATION
2 INSTALLATION
Before using the OptiCal make sure that Sections 2.1, 2.2 and
2.4 are read thoroughly.
The OptiCal enclosure is designed for bench top mounting in a laboratory type
environment. It must be positioned in a clean and level location with sufficient clearance
at the rear of the enclosure for adequate ventilation.
The OptiCal is not designed to be fully portable. However, it can
easily be moved to any suitable location for use. Before moving,
ensure that any water in the reservoir is drained and that the
RH control probe and the temperature probe in the chamber are
removed.
The OptiCal should NOT be moved while in operation.
2.1 Installing the Relative Humidity and Temperature Control Probes
The relative humidity control probe and the Pt100 temperature probe are both supplied
as accessories with the OptiCal, and are removed during transportation.
To install the probes, remove the chamber door and plug in the probes as shown in
Figure 3.
This internal RH control probe is delivered with its own calibration certificate.
RH Control
Probe
Temperature Probe




Figure 3 Probe Installation
The RH control probe and the temperature probe must always
be removed during transportation.

OptiCal User’s Manual
Michell Instruments 5
INSTALLATION
GND
OUTPUT TEMP
+ SUPPLY (8 - 35 VDC)
OUTPUT RH
BOTTOM VIEW
TOP VIEW
Control
Probe
Connector
Temperature
Probe
Connector
h
h
Figure 4 Location of Probes Inside the Climate Chamber

OptiCal User’s Manual
697079 Issue 9.2, March 2016
INSTALLATION
2.2 Filling the Water Reservoir
Before operation the water reservoir located on the front panel must be filled with
distilled water (supplied with the instrument).
Do not use tap water or demineralized water!
Figure 5 Filling the Water Reservoir
Use the filter bottle supplied to fill the water reservoir.
1. Remove the red plastic cap from the top of the reservoir.
2. Carefully fill with clean distilled water to a level between the two indicator
lines.
3. Replace the red cap on the water reservoir after filling.
Do NOT fill above the MAX indicated line as this may cause liquid
to enter the humidity chamber and adversely affect the control
process.

OptiCal User’s Manual
Michell Instruments 7
INSTALLATION
2.3 Draining the Water Reservoir
Drain the water reservoir before transporting, or if the system is accidentally overfilled.
To empty the water reservoir:
1. Remove the red caps from the bottom and top of the water reservoir.
2. Drain the water into a suitable container.
3. Tilt the OptiCal to empty it completely.
4. Re-fit the red cap after emptying.
Figure 6 Emptying the Water Reservoir
It is essential to drain the water reservoir before transporting or
when the system is not going to be used for a few weeks.
Do not re-use any of the drained water within the system.

OptiCal User’s Manual
897079 Issue 9.2, March 2016
INSTALLATION
2.4 Desiccant
The OptiCal has a container filled with a desiccant which is used to dry the chamber air.
Figure 7
Desiccant Replacement
The desiccant container can be accessed by following these steps:
1. Remove the clear plastic screw cap on the front panel.
2. Pull out the desiccant container using finger tips.
3. Fill with desiccant up to the tapered thread as shown below.
Figure 8 Level of Silica Gel Required
The natural color of the desiccant (dry silica gel) should be orange. As moisture is
absorbed the color will gradually change to transparent.
When the desiccant has become transparent, this is an indication that the instrument’s
ability to generate low humidity is reduced. It is recommended that the silica gel is
replaced or regenerated at this time.
The silica gel can be regenerated by emptying it completely from the desiccant chamber
and drying it in an oven for approximately 3 hours at a temperature between 130°C
(266°F) and 160°C (320°F). After drying it in an oven, allow the silica gel to cool before
refilling the desiccant chamber and refitting the chamber into the generator. Ensure that
the screw lid is correctly fitted.
Frequency of desiccant regeneration or replacement is dependant entirely upon the
length of time in operation. Typically, given a normal calibration profile and operation
cycle, the OptiCal can continually generate accurate and stable chamber humidity for a
period of several weeks before regeneration or replacement of the silica gel is necessary.

OptiCal User’s Manual
Michell Instruments 9
INSTALLATION
2.5 Power Supply
A single mains power supply between 85 to 264 V AC is required to operate the unit.
The power supply connection is a 3 pin IEC plug located on the rear panel of the
instrument. The ON/OFF switch and the power input fuse are in the same location,
adjacent to the power socket.
A 3-core power cable is provided, the free end of which should be wired to a suitable
earthed plug or directly connected via a fused power spur. The power cable conductors
are color coded according to the international convention:
Brown L (Live)
Blue N (Neutral)
Green/Yellow E (Earth/GND)
The instrument must be connected to an electrical earth for
safety purposes.

OptiCal User’s Manual
10 97079 Issue 9.2, March 2016
OPERATION
3 OPERATION
3.1 Preparation
3.1.1 Installing Relative Humidity Instruments for Calibration
Relative humidity probes can easily be installed into the humidity chamber through
the ports in the door. The amount and size of the ports are supplied per customer
specification.
Port openings
available per
customer specification
Blind stop
h
h
Figure 9
Probe Ports
NOTE: Ports which are not being used should be covered with a blind stop
to exclude temperature and relative humidity influences from outside the
chamber.
NOTE: If a door without ports (A000268) is used, the probes under calibration
must be placed inside the measurement chamber. To ensure good air flow, do
not overfill the chamber with probes.
The ports adapters can be changed using a port adapter removal tool (A000265)
available from Michell Instruments.
Figure 10
Port Adapter Removal Tool
Insert the two pegs on the adapter tool into the corresponding holes on the port
adapters and turn counter-clockwise to loosen, and clockwise to tighten.
Figure 11 Port Adapters and Removal Tool

OptiCal User’s Manual
Michell Instruments 11
OPERATION
3.2 Start-Up
After installing the calibration instruments, switch on the OptiCal by using the ON/OFF
switch on the rear panel of the instrument.
3.3 Local Control of Chamber Temperature and Humidity Set Points
The desired percentage of relative humidity and temperature (in °C) can be manually
set by using the humidity and temperature setting switches when the AUTO/MAN
switches are in the MAN position. Humidity or temperature control can be enabled or
disabled individually using the associated ON/OFF switch.
NOTE: Sufficient time must be allowed for the OptiCal to thermally stabilize
before monitoring the humidity and temperature readings.
Chamber Set
Humidity
Chamber Set
Temperature
Auto On On Auto
Man. Off Off Man.
245
450
Figure 12
Humidity and Temperature Setting Switches
1. Put the AUTO/MAN switches into the MAN position.
2. Put the
ON/OFF switches into the ON position.
3. Set the
REMOTE COMMUNICATION switch on the back of the instrument
to the OFF position.

OptiCal User’s Manual
12 97079 Issue 9.2, March 2016
OPERATION
3.4 Remote Control of Chamber Temperature and Humidity Set Points
To enable remote control of temperature and humidity set points follow the instructions
below:
Chamber Set
Humidity
Chamber Set
Temperature
Auto On On Auto
Man. Off Off Man.
245
450
Display Control
Figure 13 Humidity and Temperature Setting Switches
1. Put the AUTO/MAN switches into the AUTO position.
2. Put the
ON/OFF switches into the ON position.
3. Set the REMOTE COMMUNICATION switch on the back of the instrument
to the ON position.
4. Put the Optidew in REMOTE Mode. Refer to Section 4.1.
5. The OptiCal temperature and humidity set points can now be controlled
from the OptiCal application software. Refer to Section 3.4.3 and Section
3.4.4.
NOTE: If the OptiCal is used with manual set-points, put the switches into
the MAN position (refer to Section 3.3).
3.4.1 Digital Communications
Located on the front panel is a 9 way ‘D’ connector, which is used to communicate with
Opti-Soft application software or with an ASCII terminal program (see Section 5).
The communication interface is RS232.
Pin number RS232
2Tx
3Rx
5 GND
NOTE: To enable remote control of the chamber set points, both the front
panel AUTO/MAN switches should be set to AUTO and the rear panel REMOTE
COMMUNICATIONS switch set to ON. The Optidew should also be in REMOTE
Mode. Refer to Section 3.4.2 and Section 4.1.

OptiCal User’s Manual
Michell Instruments 13
OPERATION
3.4.2 Putting the Optidew in Remote Mode
On start-up, the Optidew reference is automatically in LOCAL Mode. Once the display
has stopped showing the start-up banner it is possible to change between the two modes
by simply holding down the DISPLAY CONTROL button for approximately 7 seconds. In
REMOTE Mode the display will show REMOTE MODE, indicating that communication
with a PC via the RS232 port is possible.
3.4.3 Remote Control - Manual Set Point Control
Opti-Soft has the facility to manually control the OptiCal via the manual control window.
To set the required %RH and temperature values, adjust the controls and press the
Apply button.
Figure 14 OptiCal Manual Control
3.4.4 Remote Control - Automatic Set Point Control
Opti-Soft provides a programming facility for the OptiCal, where the user can design,
open and save programs with up to 10 dwell-points.
Figure 15 OptiCal Programming
Program progress is shown by the color change in the program table and the dwell time
of the active dwell point is decremented every second to show the time remaining.