Note:These paragraphs provide information that provides a deeper understanding of the situation, but is not
essential to the proper completion of the instructions.
IMPORTANT: These paragraphs provide information that emphasizes instructions that are essential to proper setup of
the equipment. Failure to follow these instructions carefully may cause unreliable performance.
CAUTION! This symbol indicates a risk of potential minor personal injury and/or severe damage to
the equipment, unless these instructions are followed carefully.
WARNING! This symbol indicates a risk of potential serious personal injury, unless these
instructions are followed carefully.
Safety Issues
WARNING! It is the responsibility of the user to make sure all local, county, state and national
codes, regulations, rules and laws related to safety and safe operating conditions are met for each
installation.
Auxiliary Equipment
Local Safety Standards
The user must make sure that he operates all auxiliary equipment in accordance with local codes, standards,
regulations, or laws applicable to safety.
Working Area
WARNING! Make sure that power to the auxiliary equipment is turned OFF and locked out before
you perform maintenance procedures on the equipment.
Qualification of Personnel
Make sure that all personnel have manufacturer-approved training applicable to the auxiliary equipment.
Personal Safety Equipment
Make sure that operators and maintenance personnel have all safety equipment applicable to the auxiliary equipment.
Examples include safety glasses, protective headgear, safety shoes, etc.
Unauthorized Operation
Make sure that unauthorized personnel cannot gain access to the operation of the equipment.
Optica™ Operator’s Manualxi
Preface
Environmental Compliance
Waste Electrical and Electronic Equipment (WEEE) Directive
GE Measurement & Control Solutions is an active participant in Europe’s Waste Electrical and Electronic Equipment
(WEEE) take-back initiative, directive 2012/19/EU.
The equipment that you bought has required the extraction and use of natural resources for its production. It may
contain hazardous substances that could impact health and the environment.
In order to avoid the dissemination of those substances in our environment and to diminish the pressure on the natural
resources, we encourage you to use the appropriate take-back systems. Those systems will reuse or recycle most of the
materials of your end life equipment in a sound way.
The crossed-out wheeled bin symbol invites you to use those systems.
If you need more information on the collection, reuse and recycling systems, please contact your local or regional
waste administration.
The GE Measurement & Control Optica is a multi-purpose chilled-mirror hygrometer, suitable for use in a wide variety
of applications. The Optica can function with any GE Measurement & Control chilled-mirror sensor to provide the
following measurement ranges (depending on the sensor selected):
•Dew/frost point from –80°C to +85°C (–112°F to +185°F)
•Relative humidity from 0.002% to 100%
•Moisture content from 500 ppb
to over 5.71 × 105 ppm
v
v
•Temperature from -100°C to +100°C (-212°F to +212°F)
The Optica also measures and displays gas pressure using a GE Sensing PT-30A or PT-300A pressure sensor, or a
user-supplied 4–20 mA or 0–5 VDC pressure sensor.
Note:If the pressure is known to be constant, a fixed pressure can be programmed, eliminating the need for a
pressure sensor.
Using the Optica, you can simultaneously measure and display dew point, temperature and pressure, with a wide
variety of units of measure. The Optica is Ethernet-ready, so you can access the unit using the Internet for remote
monitoring applications. You can use the data logging function to record and upload weeks of data.
1.2Electronics Enclosure
The Optica is available in two configurations:
•A benchtop model, with an optional rack-mount adapter available
•A wall-mount unit, housed in a Type 4 enclosure, suitable for industrial environments
See Chapter 2, “Installation” for details on how to mount the Optica.
Optica™ Operator’s Manual1
Chapter 1. Features and Capabilities
VGA DisplaySoftkeysAlphanumeric Keypad
Power
On/Off
Switch
1.2.1Front Panel
The Optica front panel is shown in Figure 1 below. The panel includes: a display, an alphanumeric keypad for data
entry, ENTER and TAB keys, and four softkeys to the right of the display screen.
Two display options are available:
•A high-resolution, full-color, liquid crystal display (LCD) with data graphing and on-screen programming
capability (referred to as the “VGA” unit). See Figure 1 below.
•A 4-line by 40-character alphanumeric display (referred to as the “4x40” unit).
Figure 1: Optica Benchtop Version with VGA Display
1.2.2Input/Output Capability
Available inputs and outputs include the following:
•4-wire Resistance Temperature Detector (RTD) input
•4–20 mA and 0–5 VDC Pressure Sensor inputs
•Two simultaneous analog outputs, each with 4–20 mA and 0–5 VDC capability
•Two independent alarm relays (Form C, 5 Amp)
•Serial communications port
•Ethernet 10BaseT (on VGA Optica only)
The Optica uses the GE Measurement & Control patented Programmable Automatic Contaminant Error Reduction
PACER) system for automated self-cleaning and optics rebalancing. Detailed specifications for the Optica are given in
(
Appendix A, “Specifications”.
2Optica™ Operator’s Manual
Chapter 1. Features and Capabilities
1.3The System
1.3.1System Components
A complete Optica system consists of the following items:
•Electronic monitor•Temperature sensor (optional)
•Dew point sensor•Pressure sensor (optional)
•Interconnecting sensor cable•Maintenance kit
•AC line cord•User’s Manual
•Certification that the unit is traceable to the National Institute of Standards
and Technology (Certificate of Conformance)
1.3.2System Planning
The Optica can be used for a wide variety of measurement applications, including the measurement of dew points of
gasses that are at pressures that exceed the measurement range of GE sensors. In this situation be sure to check
“Process Pressure” on page 30 for installation planning.
1.4Sensors
The Optica can be configured with a chilled-mirror dew point sensor. The specific sensor is chosen according to the
expected dew point range and the environment in which the dew point is to be determined. In addition, the Optica can
be configured with a temperature and/or pressure sensor.
1.4.1Dew Point Sensors
GE offers the following sensors for various applications:
•Model 1111H - Single-stage sensor
•Model 1211H - Two-stage sensor; high pressure and temperature
•Model D-2 - Two-stage sensor
•Model SIM-12H - Two-stage heated sensor
•Model 1311DR - Four-stage, liquid or air cooled sensor
•Model 1311XR - Five-stage, liquid cooled sensor
1.4.2Temperature Sensor
•Model T-100E
1.4.3Pressure Sensor
•Model PT-30A or PT-300A
Optica™ Operator’s Manual3
Chapter 1. Features and Capabilities
41.2°F
Dew Point Temperature
(Precision Thermometer)
LED
Regulation
Thermoelectric
Heat Pump Power
Gain
Optical Reference
1.5Theory of Operation
Optical condensation hygrometry is a precise technique for determining the water vapor content in gases by directly
measuring dew point or frost temperatures. Using this technique, a metal mirror is cooled until it reaches a temperature
at which a thin layer of condensation begins to form on it. The dew layer is detected optically, and the mirror is held at
that temperature. The mirror temperature, measured with a platinum resistance thermometer, is an accurate indicator of
the dew or frost point. Because these hygrometers are so accurate, they are widely used as a standard in many of the
world’s metrology laboratories.
1.5.1Hygrometer Function
Figure 2 below illustrates how GE Measurement & Control hygrometers detect and measure dew point. The
condensate mirror is illuminated with a solid state, infrared emitter (IR). A photodetector monitors the IR light
reflected from the mirror. The photodetector is fully illuminated when the mirror is clear of dew, and it receives less
light as dew forms. A separate LED and photodetector pair are used as a known reference to compensate for any
thermally induced changes in the optical components. The photodetectors are arranged in an electrical bridge circuit,
the output current of which is proportional to the light reflected from the mirror. The bridge output controls the
electrical current to the thermoelectric cooler.
A large bridge current develops when the mirror is dry, causing the mirror to cool toward the dew point. As dew begins
to form on the mirror, less light is reflected, and the bridge output decreases. This, in turn, causes a decrease in cooling
current. A rate feedback loop within the amplifier ensures critical response, causing the mirror to stabilize quickly at a
temperature that maintains a thin dew or frost layer on the mirror surface. A precision thermometer element embedded
within the mirror directly monitors this dew point temperature.
Figure 2: Chilled-Mirror Hygrometer Diagram
4Optica™ Operator’s Manual
Chapter 1. Features and Capabilities
1.5.2Hygrometer Calibration
The Optica unit can be sent to the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland for
certification or to any National Standards lab for calibration against their primary humidity standards. A calibrated
instrument can then be used as a transfer standard in local laboratories to calibrate lower echelon instruments.
CAUTION! Field calibration of the Optica is not recommended.
Hygrometers used as calibration standards must have the following characteristics:
•The mirror thermometer must have suitable long-term accuracy (such as that obtained with a platinum
resistance thermometer).
1.5.3Other Hygrometer Applications
Many GE Measurement & Control Chilled Mirror Hygrometers are used in industrial applications in addition to
metrology. The optical condensation hygrometer is not readily damaged or contaminated by industrial process gases
that can degrade other secondary measurement schemes such as saturated salt and polymer-based sensors. If the sensor
or sampling components should become contaminated with oils, salts, etc., they can be cleaned without harm to the
sensor or impairment to the system accuracy. The performance of the hygrometer can be checked at any time by
heating the mirror above the dew point, causing the dew deposit to evaporate, then reclosing the servoloop and
checking to see that the system cools and returns to the same dew point.
The GE optical condensation sensors cover a wide range of applications limited only by the heat pumping capabilities
of the thermoelectrically-cooled mirror.
At high dew points (up to 100°C), the sensor is limited by the thermal properties of the solid state optical components
as well as the thermoelectric heat pump capacity.
In a typical application measuring sub-ambient dew points, a two-stage thermoelectrically-cooled mirror can reach a
temperature approximately 65°C lower than an ambient (heat sink) temperature of +25°C. The thermoelectric cooler
pumps heat from the mirror into the heat sink. By reducing the temperature of the heat sink with a coolant such as
chilled water, or by applying the sensor in a low-temperature condition such as monitoring of a test chamber, even
lower dew points can be measured. In meteorological applications where the heat sink temperature is considerably
lower, frost points down to –75°C can be monitored.
Four- and five-stage sensors are available for measuring the lowest dew/frost points.
Optica™ Operator’s Manual5
Chapter 1. Features and Capabilities
Mirror Heats
Start of Cycle
End
CoolingHeating
Data is Sampled
and Held
(3 min)
Optical System
Automatically
Adjusts for
Correct
Reflectance
(5 sec)
Prevailing
Dew Point
Mirror Cools
and Coalesces
(30 sec)
Mirror Returns
To Dew Point
(60 sec)
To Dry State
(90 sec)
Before
PACER Cycle
After
PACER Cycle
1.6The PACER Cycle
GE Measurement & Control has developed and patented a compensation technique called PACER (Programmable
Automatic Contaminant Error Reduction) that is very effective in reducing the Raoult Effect error associated with
soluble contaminants, particularly for near-ambient dew points. The Optica is equipped with the
AUTO balance as found on earlier models. The user can choose which self-cleaning and balancing routine to run
depending on the severity of the contamination.
PACER cycle, diagrammed in Figure 3 below, begins with a coalescence period, during which the mirror is cooled
The
well below the dew point of the sample gas, condensing out a large amount of water.
PACER cycle as well as
This excess water easily dissolves any water-soluble contaminants. The mirror is then heated. During the heating
phase, the large puddles of water gradually evaporate, carrying increasingly heavy concentrations of salts as the
puddles become smaller. Finally, when all the puddles have evaporated, dry “islands” of crystallized salt are left on the
mirror. The area between the islands (80-85% of the mirror surface) is now clean and shiny, whereas before the
cycle it may have been completely covered. The total amount of contamination has not been reduced, but instead,
redistributed as shown in Figure 4 below, with more clean mirror surface available for dew formation. The reflected
light signal is then electronically balanced against the reference.
Figure 3: A Typical PACER Cycle
PACER
Figure 4: Results of the PACER Cycle
6Optica™ Operator’s Manual
Chapter 2. Installation
Dimensions =
*Add .75” (19 mm)
6.5*
13.5
13
(330)
(343)
(165)
inches
(mm)
for Feet
Chapter 2.Installation
2.1Introduction
This chapter explains the installation of the benchtop and wall-mount versions of the Optica, the various sensors used
with the system and the I/O and power wiring. To install your Optica, refer to the instructions and drawings for your
specific configuration:
•Benchtop - see “Benchtop Optica Installation” on page 7
•Wall-Mount - see “Wall-Mount Optica Installation” on page 12
WARNING! To ensure the safe operation of this unit, you must install and operate the Optica as
described in this manual. In addition, be sure to follow all applicable safety codes and regulations for
installing electrical equipment in your area.
2.2Benchtop Optica Installation
2.2.1Mounting the Benchtop Optica
The Optica benchtop dimensions are shown in Figure 5 below. Two feet on the bottom of the case can be unfolded to
raise up the front for easier viewing, if desired.
Figure 5: Optica Benchtop Dimensions
Optica™ Operator’s Manual7
Chapter 2. Installation
2.2.2Using the Rack Mounting Option
There is an optional kit for mounting the benchtop unit in a standard 19-inch rack (see Figure 6 below, Figure 7 on
page 9, and Figure 8 on page 10). The two brackets are attached to the front panel using four #8 screws. The Optica is
mounted to the brackets using the eight mounting holes located just in front of and behind the unit’s feet.
Figure 6: Optica Rack-Mount Adapter
8Optica™ Operator’s Manual
2.2.2Using the Rack Mounting Option (cont.)
1.32
(33.5)
1.11
(28.2)
6.52
(165.6)
2.69
(68.3)
3.91
(99.3)
19.00 (482.6)
14.62 (371.3)
12.53 (318.3)
0.50 (12.7)
2.19 (55.6)
1.32
(33.5)
2.88
(73.2)
2.38
(60.5)
8.75
(222.3)
4.00
(101.6)
3.00
(76.2)
2.74 (69.6)
3.23 (82.0)
18.25 (463.6)
13.53 (343.7)
7.07 (179.6)
0.59 (15.0)
0.09
(2.3)
FH-032-8
4 places
0.38
(9.7)
Note: Dimensions are in inches (millimeters).
Chapter 2. Installation
Optica™ Operator’s Manual9
Figure 7: Optica Rack-Mount Adapter - Front Panel
Chapter 2. Installation
Note: Dimensions are in inches (millimeters).
0.66 (16.8)
0.75 (19.1)
1.44
(36.6)
11.00 (279.4)
1.50
(38.1)
1.13 (28.7)
1.00 (25.4)
1.09 (27.7)
0.55 (14.0)
3.91
(99.3)
5.86
(148.8)
6.00
(152.4)
0.98 (24.9)
3.19 (81.0)
1.82
(46.2)
0.59 (15.0)
0.80 (20.3)3.03 (77.0)
1.00 (25.4)
1.00 (25.4)
12.41 (315.2)
1.04
(26.4)
2.2.2Using the Rack Mounting Option (cont.)
Figure 8: Optica Rack-Mount Adapter - Bracket
10Optica™ Operator’s Manual
Chapter 2. Installation
*Note: Depending on the model revision, the LAN connector is located in one of two places.
2.2.3Wiring the Benchtop Optica
2.2.3aInput Power
The Optica operates with input power from 100 to 120 VAC at 4 amps, or from 200 to 240 VAC at 2.5 amps. It is
designed for a nominal 100, 115 or 230 VAC source. A switch on the rear panel selects the appropriate voltage range
(see Figure 9 below).
•The 115 VAC setting operates over a range of 100 to 120 VAC
•The 230 VAC setting operates over a range of 200 to 240 VAC
The Optica’s voltage and frequency rating are listed on the rear panel.
2.2.3bSensors
Connect the dew point sensor cable to the 25-pin connector in Slot B on the Optica’s rear panel (see Figure 9 below).
Connect the optional temperature sensor cable to the 9-pin connector in
sensor and other I/O wiring connects to the terminal block in
Slot A.
Slot B on the rear panel. The optional pressure
Figure 9: Optica Benchtop Rear Panel
Optica™ Operator’s Manual11
Chapter 2. Installation
Dimensions =
6.5
13.7
(348)
(165)
inches
(mm)
16.725
(425)
Use the two mounting holes
to secure the enclosure to
the chosen wall, using 1/4”
fasteners of the appropriate
type for the wall material. Be
sure that the mounting holes
are located on a vertical line
on the wall.
below unit for cabling.
Allow adequate space
17.43"
(443 mm)
Ø.261 (6.63 mm)
2 places
2.3Wall-Mount Optica Installation
The Optica Wall-Mount unit is designed to mount on a flat, vertical surface, such as a wall or panel. To mount the
wall-mount version, see Figure 10 and Figure 11 below.
2.3.1Mounting the Wall-Mount Optica
Figure 10: Optica Wall-Mount Unit Dimensions
Figure 11: Optica Wall-Mount Unit Mounting Hole Locations
12Optica™ Operator’s Manual
Chapter 2. Installation
I/O Terminal Blocks
Ethernet LAN Connector
I/O Cable Gland
Serial Port
Temperature Sensor
Dew Point Sensor
AC Wiring Terminal Blocks
AC Power Input Gland
DEW POINT
Gland for
I/O Wiring
INPUT
LAN
COM
Optional Ethernet
LAN Connector
Serial Port
Dew Point Sensor
Gland for
AC Power
Wiring
4 ASB 250V TYPE T
115/230 VAC 50-60 Hz
AC LINE
TEMP
Temperature Sensor
2.3.2Wiring the Wall-Mount Optica
All connections to the wall-mount unit are made through the panel at the bottom of the case as shown in Figure 12 and
Figure 13below. Any I/O cabling is brought into the unit through a gland at the lower left of the case and connects to
the terminal blocks on the left side of the case. Wiring for these connections is shown in Figure 15 on page 14. The
dew point sensor and temperature sensor cable connectors are located near the center of this panel.
Optica™ Operator’s Manual13
Figure 12: Wall-Mount Wiring Entrance Locations
Figure 13: Wall-Mount Bottom Panel (viewed from bottom of Case)
Chapter 2. Installation
Front of Case
Top
L
Case
NG
of
AL2NC
OUT A
0-5
PRESSURE
I in
Benchtop Unit
RTN
4-20
OUT B
0-5
V in
+V
Case
of
Front
NO
ALARM 1
ALARM 2
NC
COM
4-20
NC
NO
NO
COM
Slot A
COM
NO
COM
AL1NC
+V
Wall-Mount Unit
PRES
I in
RTN
V in
Top
OUT B
OUT A
4-20
4-20
0-5
0-5
2.3.2aInput Power
Power wiring enters the case through a gland fitting at the lower right of the unit and connects to a screw terminal block
mounted on the right side of the case. Wiring of this terminal block is shown in Figure 14 below. The voltage and
frequency rating and tolerances, as well as fusing data, are listed on the bottom of the unit.
WARNING! There is a potential shock hazard at this location. Disconnect and lock out the main
power prior to any service procedures.
Figure 14: Wall-Mount AC Power Wiring
2.4Output Wiring
The benchtop Optica outputs are connected to removable terminal blocks on the rear panel. Figure 9 on page 11 shows
the location of the benchtop unit terminal blocks and Figure 15 below shows the
The Wall-Mount Optica input/output terminal blocks are located inside the front door as shown in Figure 12 on
page 13. Cabling is brought in through the gland on the bottom of the unit and wired to the terminal blocks shown in
Figure 15 below.
Note:Output programming is described in Chapters 4, 5 and 6.
14Optica™ Operator’s Manual
Figure 15: Benchtop and Wall-Mount Input/Output Terminal Blocks
Slot A connections.
Chapter 2. Installation
V
out
T
actualTlower
–()
T
upperTlower
–()
----------------------------------------
5×=
230–()
1000–()
---------------------
5×1.15V=
I
out
mA()
T
actualTlower
–()
T
upperTlower
–()
----------------------------------------
204–()×4+=
230–()
1000–()
---------------------
16()×4+7.68mA=
2.4.1Analog Outputs
Note:When the Optica is being programmed, the analog outputs provide 4–20 mA and 0–5 VDC signals representing
the designated parameters.
•For 4–20mA output, connect to terminals labelled 4–20 (+) and RTN (–).
Note:The maximum load allowed for current output is 500 Ohms.
•For 0–5 VDC output, connect to terminals labelled 0–5 (+) and RTN (–).
Note:The maximum current allowed for voltage output is 5 mA.
Example:
Assume a temperature output, scaled to range from 0°C (T
of 23°C (T
actual
):
The voltage output is calculated by:
yielding an output voltage of 1.15V.
The current output is calculated by:
yielding an output current of 7.68 mA.
) to 100°C (T
lower
), with a measured actual temperature
upper
Optica™ Operator’s Manual15
Chapter 2. Installation
V
out
T
actualTlower
–()
T
upperTlower
–()
----------------------------------------
51–()×1+=
230–()
1000–()
---------------------
4×1+1.92V=
2.4.1aAdditional Voltage Outputs
It is possible to use either analog current output as an additional voltage output by connecting a precision resistor from
the current output to its return. A voltage will be produced equal to the output current times the load resistance. To
produce a voltage output range of 1 to 5 volts, connect a 250 ohm resistor (0.1% tolerance recommended).
Using a 250 ohm resistor, the voltage output is calculated by:
yielding an output voltage of 1.92V for this example.
2.4.2Alarm Outputs
Each alarm output connects to the contacts of a 5-Amp, Form C (SPDT) relay.
Make connections as follows:
•For normally open contacts, connect to NO and COM.
•For normally closed contacts, connect to NC and COM.
Any available parameter can be used to control an alarm relay by programming the parameter name and its threshold
values. An alarm can also be programmed to monitor the state of the Control,
Chapter 4, 5 or 6 for programming instructions.
Both Upper and Lower threshold values are programmed for each parameter. These values designate an alarm band.
How they are used depends on the programmed alarm type. Details are shown in “Inner Band Alarm” on page 17 and
“Outer Band Alarm” on page 17.
PACER Balance, or Service indicators. See
16Optica™ Operator’s Manual
Chapter 2. Installation
UPPER edge of band
LOWER edge of band
Parameter
Alarm
Deactivated
Alarm
Deactivated
Alarm
Activated
“NC” Contacts
Closed
“NC” Contacts
Closed
Alarm
Activated
“NO” Contacts
Closed
“NO”
Closed
Contacts
“NO” Contacts
UPPER edge of band
LOWER edge of band
Parameter
Closed
Alarm
Deactivated
Alarm
Deactivated
Alarm
Activated
“NC” Contacts
Closed
“NC” Contacts
Closed
“NC” Contacts
UPPER edge of band
LOWER edge of band
Parameter
Closed
Alarm
Activated
Alarm
Activated
Alarm
Deactivated
“NO” Contacts
Closed
“NO” Contacts
Closed
2.4.2aSet Point Alarm
For the Set Point alarm type, the alarm band provides hysteresis to prevent frequent operation of the alarm relay when
the parameter is near the specified value. The relay is
deactivated when the parameter goes below the lower limit.
activated when the parameter exceeds the upper limit, and
Figure 16: Set Point Alarm
2.4.2bInner Band Alarm
For the Inner Band alarm type, the alarm relay activates whenever the parameter value is between the lower and upper
limits.
Figure 17: Inner Band Alarm
2.4.2cOuter Band Alarm
For the Outer Band alarm, the alarm relay activates whenever the parameter value is greater than the upper limit or
less than the lower limit.
Figure 18: Outer Band Alarm
Optica™ Operator’s Manual17
Chapter 2. Installation
2.4.3Serial Output
The Serial Output connector is located at the lower left of the rear panel of the bench-mount unit, and the bottom panel
of the wall-mount unit. The output provides RS-232 serial communications between the unit and a terminal or a PC
running in terminal emulation mode.
The connector is a standard 9-pin D connector. For connection to another serial device, the cable is wired as shown in
Table 1 below. For a basic interface without handshaking, only pins 2, 3 and 5 (RX, TX and GND) on the Optica
connector are needed. Pin connections are given for both 25-pin and 9-pin devices.