GE DewPro MMY 245 User manual

DewPro MMY245 Installation and Operation Manual
GE General Eastern
DewProMMY 245
Portable Moisture Analyzer
Installation and Operation Manual
GE Measurement & Sensing Technologies
GE General Eastern

DewPro MMY245 Installation and Operation Manual
GE General Eastern
General Notes
Attention!
This is a portable moisture analyzer. The success and accuracy of moisture measurements and of field
validation depends on the integrity of the care exercised in operating this equipment. All fittings and
tubing should be tightened properly and examined prior to each use for thread or quick connect fitting
damage, leaks or crimped hoses. If any damage is suspected, do not place the unit in service until the
suspected damage is repaired. DO NOT alter or modify any of the supplied components. This will not
only void the Warranty but could rupture components causing injury or death. Tampering with internal
components will likely produce errors in the instrument readings.
Caution!
Before using or installing the DewPro

MMY 245, please read all instructions.
Safety!
The DewPro

MMY 245 Portable Moisture Analyzer is designed for connection to pressurized
gaseous systems. Be certain to de-pressurize the system before connecting or disconnecting the hoses
or fittings to the analyzer or at the process connection.
Disclaimer
General Eastern Instruments, Inc. reserves the right to change or modify our products in appearance or performance specifications at any time
and without notice. Therefore, information in this document is subject to change without notice and does not represent a commitment on the
part of General Eastern Instruments, Inc.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and
recording, for any purpose without the express written permission of General Eastern Instruments, Inc.
Technical Assistance
If you should have any questions regarding the product described in this document, or need further
assistance, please contact your local General Eastern Instruments (GEI) representative or the factory at
800-33HUMID (800-334-8643). When contacting the factory for technical support, please have your
serial number ready. This number is located inside the unit and can be accessed by loosening the two
knurled screws on the top of the unit.
Serial Number: _______________________________

DewPro MMY245 Installation and Operation Manual
GE General Eastern
TABLE OF CONTENTS
1 General System Information __________________________________________________3
1.1 Unpacking and Inspection_________________________________________________________3
1.2 System Description_______________________________________________________________4
1.2.1 Portable Trace Moisture Analyzer ______________________________________________________ 4
1.2.1.1 Versatility_____________________________________________________________________ 4
1.2.1.2 Safety ________________________________________________________________________ 4
1.2.1.3 User Friendly Operation__________________________________________________________ 4
1.2.2 Field Validator _____________________________________________________________________ 5
1.3 Theory of Operation _____________________________________________________________5
1.3.1 Sensor Theory______________________________________________________________________ 5
1.3.2 Sample System Operation_____________________________________________________________ 5
1.3.3 Software Features ___________________________________________________________________ 6
1.3.4 Sample Conditioning Practices and Precautions____________________________________________ 6
1.3.4.1 Internal Construction ____________________________________________________________ 6
1.3.4.2 Avoid Liquid Samples ___________________________________________________________ 6
1.3.4.3 Avoid High Temperatures ________________________________________________________ 6
1.3.4.4 Avoid High Pressure Samples _____________________________________________________ 6
1.3.4.5 Hazardous Gas Handling _________________________________________________________ 6
1.3.4.6 Avoid Particulate Contamination___________________________________________________ 6
1.3.4.7 Avoid Corrosive Chemicals _______________________________________________________ 7
1.3.4.8 Avoid Ambient Air _____________________________________________________________ 7
1.3.4.9 Piping Recommendations_________________________________________________________ 7
Dimensions _________________________________________________________________________7
Basic Operation ________________________________________________________________8
2.1 Operating Controls ______________________________________________________________8
2.2 Display Elements ________________________________________________________________8
2.3 Basic Sampling or Spot-Checking __________________________________________________9
2.4 General Operation Practice _______________________________________________________9
2.4.1 Mapping spot check route____________________________________________________________ 10
2.4.2 Temporary Monitoring ______________________________________________________________ 10
2.4.3 Moisture Measurement Practice _______________________________________________________ 10
2.4.3.1 Checking Dryer Performance_____________________________________________________ 10
2.4.3.2 Quality Assurance _____________________________________________________________ 11
2.5 Instrument Setup / Programming _________________________________________________11
2.5.1 Matrix Orientation _________________________________________________________________ 11
2.5.2 Special Functions of the Push Buttons __________________________________________________ 13
2.5.3 Function Guide ____________________________________________________________________ 13
2.5.4 Matrix Field Details ________________________________________________________________ 13
2.5.5 Special Output and Input Functions ____________________________________________________ 15
2.5.6 Interconnection ____________________________________________________________________ 16
2.5.6.1 External Power Option__________________________________________________________ 16
2.5.6.2 External Scalable Input Option. ___________________________________________________ 16
2.5.6.3 Voltage Inputs ________________________________________________________________ 16
2.5.6.4 Output connections ____________________________________________________________ 17
3 Troubleshooting ___________________________________________________________17
3.1 General Troubleshooting Practice _________________________________________________17
3.2 Error Codes ___________________________________________________________________18
4 Field Validator Operation ___________________________________________________19

DewPro MMY245 Installation and Operation Manual
GE General Eastern 2
4.1 Optimum Validation Practice _____________________________________________________20
4.2 MMY 3 Transmitter Preparation__________________________________________________21
4.3 Validator Connection Options ____________________________________________________21
4.3.1 Transmitter Vent (series) Connection___________________________________________________ 22
4.3.2 Vacuum Application Connection ______________________________________________________ 22
4.3.3 Parallel Connection_________________________________________________________________ 23
4.3.4 Closed Loop Connection ____________________________________________________________ 24
4.4 Field Validator Setup____________________________________________________________25
4.4.1 Matrix Orientation _________________________________________________________________ 25
4.4.2 Single Point Validation Function Guide _________________________________________________ 26
4.4.3 Two-point Validation Function Guide __________________________________________________ 26
5 Troubleshooting Validator Operation __________________________________________27
6 Instrument Specifications____________________________________________________28
7 Appendix _________________________________________________________________29

DewPro MMY245 Installation and Operation Manual
GE General Eastern 3
1 General System Information
1.1 Unpacking and Inspection
Upon receipt of the DewPro® MMY245, examine the shipping carton for broken or open packing,
distortion, or any other evidence of mishandling. If inspection indicates damage to the unit or any of its
components, notify the carrier (within 15 days of delivery) and request an inspection. Move the carton
to a clean work area and unpack. The carton you receive should contain:
DewPro® MMY245
Installation and Operation Manual
All MMY 245 accessories ordered as separate line items
Compare the model number with the product structure below to ensure proper receipt of order. If an
error should be discovered, do not put the instrument into service and contact the factory immediately.
Product Structure
1 Certification
R Standard
Y Other
2 Pressure Compensation
R Basic configuration
P Pressure sensor built-in for ppm compensation
MMY245-
Accessories
Part No. Description
63005033 Carrying case including shoulder strap
63005032 Shoulder strap
63004006 Cable assembly, MMY 245 to DewProMMY 30, RS485 cable
63004005 Connector/cable assembly, RS485 DewPro(RS 485 communication cable for
installation in the transmitter for external connection to P/N 63004006)
63002013 Connector/cable assembly, external power and non-I.S. outputs.
Gas Connection Accessories
63000598 Gas Inlet and outlet connection, ¼” tube 316 SS
63002201 Gas Inlet and outlet connection, 6mm tube 316 SS
63002199 Gas inlet, 3 ft. PFA hose with quick connect set and ¼” tube process connection
63002200 Gas inlet and outlet connection, ¼” tube PFA
63005036 Coalescing Filter for Glycol Contactor Applications
63005037 Pressure Regulator for samples greater than 125 psig.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 4
1.2 System Description
1.2.1 Portable Trace Moisture Analyzer
The DewProMMY 245 Moisture Analyzer is designed primarily as a portable moisture instrument
that can be used in a variety of gaseous applications. The portable unit can be used to quickly spot
check the performance of dryers for compressed air, natural gas. Checking pure gas supplies, accurately
testing SF6 gas in high power switchgear and transformers, gasified LNG, breathing air or oxygen and
many other applications are easy with the MMY 245 portable analyzer.
This is a well balanced, compact, easy to use versatile analyzer complete with all the units of measure
and connectability required to keep track of the moisture critical processes in your facility. The rugged
DewProMMY 245 case has been selected to provide the maximum protection for the internal
components in most any industrial environment where it is used.
With the MMY 245 Portable Moisture Analyzer, measurement time is typically 5 minutes. The sensor
is kept in a very dry desiccated environment with the dry-down taking place while the instrument is
inactive or being transported to the next measurement point. For complete instrument specifications,
see Section 6.
1.2.1.1 Versatility
The variety of applications in which the DewProMMY 245 can be used is limited only by its range of
operation for moisture and pressure and by the chemical nature of the gas sample. The unit is designed
to be used for dry samples having a dew point temperature below freezing at the pressure of the sample
introduced to the unit. Some typical applications are listed below:
Desiccant dried air Dried Natural Gas Argon gas for welding
Nitrogen gas supplies Breathing air SF6gas for switchgear
Helium gas supplies Oxygen gas supplies Hydrogen cooling loops
Instrument air Glove box gas purifier loops Ethylene Production
Heat treating atmosphere
generators
Gas Bottle filling operations … and many others.
The processes listed above often require many different units of measure and the MMY 245 is able to
provide readouts in most of the common units necessary for these applications. The unit of measure is
simply selected from the operating keypad. An optional pressure sensor will automatically correct for
changes in pressure that occur in a given stream or when spot-checking several sample points
throughout a facility or process.
1.2.1.2 Safety
The DewProMMY 245 has been designed to meet or exceed the FM requirements for Class I,
Division 1 environments for portable instruments.
1.2.1.3 User Friendly Operation
The normal method of measurement is to connect the DewProMMY 245 to the process sample tap via
a short flexible high-pressure hose that employs a quick-connect fitting. The sample valve on the
process piping is opened to start a sample flow to the unit. After allowing the sample flow to purge the
hose for 15-30 seconds, the handle on the side of the analyzer is rotated up to the vertical position. This
directs the sample across the sensor. The power button is pressed and the readout provides the moisture
value in the desired unit of measure.
The analyzer is programmed using the keypad and a matrix to select the moisture unit of measure,
temperature unit of measure and other operating parameters. An optional pressure sensor can provide
real time correction for concentration units of measure. In lieu of the optional sensor, a pressure
constant can provide the proper value with known pressure conditions.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 5
1.2.2 Field Validator
This portable unit can validate the readings of permanently installed GEI loop-powered dew point
transmitters while they are in the loop, simply by connecting the MMY 245 to the DewPro’soutlet and
monitoring the same sample. This is accomplished by monitoring the same sample as the transmitter by
connecting to its outlet. Either a single-point or two-point validation mode can be selected via the
keypad and matrix. An RS-485 connection between the portable and the transmitter provides for digital
correction of the transmitter’s calibration data. The procedure takes from one to four hours and
eliminates transmitter downtime and reduces the need for sending transmitters back to the factory for
recalibration. The complete description of this feature can be found in section 4 of this manual. This
validation is not a field calibration technique since most calibrations require the standard to be four
times more accurate than the device under test. The MMY 245 does not have that accuracy advantage
and should be used to adjust transmitters in the field with this in mind.
1.3 Theory of Operation
The DewProMMY 245 operates as a self-contained moisture analyzer system comprised of a sensor,
electronics, power source, and sample system.
The sensor is an advanced Planar Gold/Aluminum Oxide sensor designed to respond quickly to changes
in measuring conditions. It has been used extensively in trace moisture analyzers for several years. This
trusted sensor is resistant to contamination and has proven to be a rugged and stable platform for
consistent results in measurement accuracy and reliability.
The electronics package was designed using the basic DewProtechnology developed four years prior
to the introduction of the portable configuration. With proven reliability and ruggedness and with the
addition of memory and energy management components, the MMY 245 provides the flexibility
required for many applications.
Four standard “D” cell batteries supply the power for the MMY 245. Standard alkaline batteries are
included and are recommended for replacement.
The internal sample system provides for purging the hoses after they are connected to the sample tap
and then directs the sample across the sensor.
1.3.1 Sensor Theory
The Planar Gold / Aluminum Oxide sensor is a capacitance based technique for detecting the moisture
content in gaseous samples. This sensor is manufactured using semiconductor techniques on wafers of
ceramic substrate. The sensor is manufactured by depositing a pure aluminum layer over gold contact
pads on a ceramic substrate. The aluminum is partially anodized using a proprietary process and a thin
film of permeable gold is deposited over the oxide layer. The aluminum oxide is a porous insulator and
provides a space for moisture molecules to reside at equilibrium with the sensor environment. The
permeable gold conductive layer allows moisture molecules to move freely into or out from the oxide
layer and acts as one plate of the capacitor. The aluminum layer beneath the oxide acts as the opposing
plate for the capacitor. After the sensors are created on the wafer, they are diced apart and each sensor
is then bonded to a pressure rated feed-through on a probe. The probe supports the sensor in the process
environment for which it is rated.
1.3.2 Sample System Operation
The main component of the sample system in the DewProMMY 245 is essentially a valve. The valve
emulates a four-way process valve during operation. In the “dry” or horizontal position, the sensor is
exposed to a very dry, -85° to –95°F, (-65° to –72°C) dew point environment created by a very strong
desiccant. This keeps the sensor dry and ready to measure. Any sensor will respond quickly to
increasing moisture and dries down much more slowly. In the “measure” or vertical position of the
valve handle, the sample stream is directed across the sensor to allow the measurement to be made.
Just as in a four-way process valve, there is a second function in operation concurrent with the “flow”
description above. When in the “dry” position, the passage for the sample connection inlet is connected
to the outlet for purging the connecting hoses. This purging operation is critical for making the
measurement as quickly as possible since a fresh sample is transferred to the immediate sensor location

DewPro MMY245 Installation and Operation Manual
GE General Eastern 6
while the sensor itself is kept dry and ready to measure. Purging for 3-5 minutes is recommended. In
the “measure” position of the valve handle, the desiccant chamber is closed from any possible contact
with the incoming sample gas. This prevents the desiccant from being contaminated or consumed too
quickly. The desiccant should last several months under daily use for several readings per day.
An optional pressure transducer can be ordered to provide pressure information to the electronics for
compensation of readings in concentration units of measure. These units of measure require a total
pressure value to correctly compute the proper moisture reading. The pressure information can be
displayed and used for correction of the moisture reading from this pressure sensor or from a direct
input of a constant value as selected using the keypad.
1.3.3 Software Features
The software architecture is based on a matrix of operating parameters. Each parameter setting
determines the function of the software to display and compute the proper moisture value, to control
outputs and to communicate with field mounted MMY series transmitters. The matrix settings also
determine how to treat optional inputs and when they should be used in the computation of a moisture
value. The complete operation of the matrix is described in the Instrument Setup portion of the Basic
Operation, Section 2 in this manual.
1.3.4 Sample Conditioning Practices and Precautions
1.3.4.1 Internal Construction
All the wetted surfaces of the MMY 245 DewProare electro-polished non-hygroscopic metal
components of either stainless steel or anodized aluminum. Introducing clean samples will prevent
these surfaces from becoming contaminated.
1.3.4.2 Avoid Liquid Samples
Avoid ANY liquid exposure of the sample lines and the instrument. Liquids will damage the unit and
void the Warranty.
1.3.4.3 Avoid High Temperatures
Avoid high or low temperatures. The MMY 245 can be operated over a temperature range of 4°F to
104°F (-20° C to +40° C). Operating the unit at higher temperatures can damage the sensor and the
electronics. The LCD is not likely to work if the unit is operated below the normal stated range.
1.3.4.4 Avoid High Pressure Samples
The maximum inlet pressure rating for the MMY 245 is 150 PSIG or 10 Bar. If the process or sample
pressure is greater than this, a pressure regulator should be used to drop the pressure to within the
instruments range.
1.3.4.5 Hazardous Gas Handling
When making connections to samples of flammable or hazardous gases, exercise care to insure leak
free connections. Be aware that leaks can create fire, explosive or toxic conditions that should be
avoided. The MMY 245 is designed to meet Class I, Division 1, Group B-G environments; but the
integrity of the sample connections to the instrument is the responsibility of the user.
1.3.4.6 Avoid Particulate Contamination
A sample contaminated with particulates will deposit some of this material inside the unit producing
more surface area and sites where moisture could be trapped. This could result in higher than actual
readings. If the sample contains particulates or aerosols, it must be filtered to remove this
contamination.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 7
Figure 1
1.3.4.7 Avoid Corrosive Chemicals
Introducing corrosive chemicals can pit or corrode the internal components and can damage the sensor.
Avoid attempting measurements in streams containing chlorine, HCl, and other strong acid or base
gases.
1.3.4.8 Avoid Ambient Air
The MMY 245 is a trace moisture analyzer. Ambient air can contain as much as 2% water. The
instrument is capable of measuring down to sub ppmvmoisture in samples to 150 psig, so avoid leaving
the operating handle in the measure position when not connected to a sample flow. Ambient air
exposure over long periods of time can move large amounts of moisture into the measurement cell and
eventually cause the sensor to drift.
1.3.4.9 Piping Recommendations
Connection the MMY 245 to the process or sample tap in the proper manner will insure the most
accurate measurements. Connecting tubing should be made from materials that are non-hygroscopic
and capable of handling the sample pressure. Keeping the length of connecting tubing as short as
possible will allow faster readings since the moisture in the sample arrives quicker than with longer
lines. Materials that are recommended include stainless steel, and PFA tubing especially for dew points
below –65°C, Copper and PTFE tubing. Rubber, Tygon and other plastic or polymer tubing is NOT
recommended for ANY application. Insure that all connections at the sample tap and at the instrument
are leak tight.
1.4 Dimensions

DewPro MMY245 Installation and Operation Manual
GE General Eastern 8
2 Basic Operation
The MMY 245 operation is simple and
intuitive. Provide the instrument with a
sample of gas and direct it to the
sensor using the handle on the side of
the instrument, apply power and let the
analyzer tell you when the
measurement is stable and should be
taken.
The instrument operates best when
measuring pressurized samples over a
range of 20-150 psig. Satisfactory
measurements can be made at lower
pressures, even at vacuum, although a
longer time may be required since
there are not as many exchanges per
minute at these lower pressures.
Techniques for these low-pressure
measurements will be discussed later
in this manual.
2.1 Operating Controls
The electronic operating controls for the MMY 245 are found directly in front of the carrying handle
and the flow path control is located on the left side of the instrument. This “operating handle” of the
instrument puts the sensor into a desiccant environment or directs the flow of the sample across the
sensor.
The electronic controls provide access to the analysis of the sample. These electronic controls consist of
six membrane switches (see Figure 2) located below the digital display and are used to power the unit
and control the various functions of the unit. The POWER key will turn the unit on or off. The HOME
key will display the matrix position V0 H0 or alternately V4 H0. Pressing the Vand Hkeys advances
the vertical or horizontal position within the matrix and the display will show the contents of that
position. Pressing the + and – keys increments or decrements the value in the matrix cell described in
the right side of the display. These matrix and operating functions will be described on succeeding
pages.
2.2 Display Elements
There are three distinct display elements consisting of a large
digital readout where values are shown, a smaller digital
section to the right where four characters are displayed
showing the location in the matrix where the values are
generated, and a bar graph across the bottom.
The MMY 245 takes the guesswork out of waiting for the
measurement to stabilize. The instrument display (see
Figure3) includes a rate-of-change bar graph indicating a
reading is changing or stable. A changing reading will cause
the bar graph to include additional segments in any portion
of the bottom of the display. The direction and amplitude
illustrated by the arrows indicate the required change in the
reading. This feature allows the operator to know the reading
has stabilized and can be recorded correctly. Below, several
different measurement techniques are discussed from the perspective of connecting the sample to the
unit; but the basics of operation remain the same.
-48.6
V
H
0 0
-48.6
V
H
0 0
Reading Still Changing
Stable Reading
Figure 3
Figure 2
-
V
0
HOME
V
H
+
-
POWER

DewPro MMY245 Installation and Operation Manual
GE General Eastern 9
2.3 Basic Sampling or Spot-Checking
Sampling or spot-checking of a pressurized gaseous sample is the primary design function of operation
the MMY 245. The following general procedure describes this fundamental operation:
WARNING! The MMY 245 has a maximum pressure of 150 psig or 10 bar(g).
Connecting the unit to a sample pressure could cause damage to the unit or
personal injury or death.
1. Connect the analyzer to the sample source connection using either hard tubing and the appropriate
fittings, or the hose and fitting set P/N 63002199 (see Figure 4.) and initiate the flow by opening
the sample tap valve.
Figure 4
2. Allow the sample to purge the connecting tubing for a few minutes.
WARNING! If there is any evidence of aerosols or the presence of condensate in
the exhaust, DO NOT PROCEED. The unit is designed for gaseous use only and
any liquid droplets or aerosols will damage the desiccant chamber.
3. Turn on the power by pressing the power switch.
4. Rotate the handle to the measure position (vertical).
5. Observe the rate-of-change bar graph indicator until both arrowheads appear indicating the reading
has stabilized.
6. Record the moisture value.
7. Rotate the handle back to the “dry” position.
8. Turn off the power by pressing the power switch.
9. Disconnect the analyzer from the sample source.
2.4 General Operation Practice
Making a moisture measurement with the DewProMMY 245 is simple but there are some general
moisture measurement practices that should be followed. If these practices are followed, the MMY 245
will provide many years of reliable service.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 10
2.4.1 Mapping spot check route
If more than one sample point is to be checked on a regular basis, it is best to map out the route the
operator should follow. If time permits, the route should be chosen for the best measurements instead of
the shortest distance traveled. Simply stated, this method measures the driest sample first and moves
through the route from the measurements that have proven to be the driest to the wettest in sequence.
This allows the sensor to respond faster since getting wet is naturally faster than getting dry. This
routing can only be determined by trial and keeping good records.
2.4.2 Temporary Monitoring
The MMY 245 is to be used in either a spot check mode or a temporary measurement mode. A spot
check mode is when an operator takes the unit to a sample tap and measures the moisture in the sample
and disconnects the unit and moves on to perhaps the next sample tap. Temporary moisture monitoring
is where the instrument is to be left connected to a sample unattended and the moisture values recorded
electronically or by periodic observation.
The MMY 245 is supplied with two analog outputs for conveniently connecting to an external
recording or logging device. The battery life can support this mode of operation for a few weeks but the
unit also provides for an external DC power source to power the unit. These connections are made
using the cable connection on the front of the unit. The cable can be ordered as an accessory.
Warning: Neither of these connections should be used in hazardous or electrically classified
areas.
2.4.3 Moisture Measurement Practice
Every process and application is different and these differences must be considered; but using good
general practices will result in better and more accurate measurements.
1. Do not introduce samples at greater than the rated pressure of 150 psig (10 barg).
2. Do not introduce samples of gases corrosive to aluminum or gold into the unit. This will damage
the sensor and will void the warranty.
3. Do not introduce samples of known high moisture or samples saturated with water into the unit.
The sensor can be damaged and will not be covered under warranty. Observe the outlet port to see
if the escaping sample shows evidence of aerosols. If so, do not attempt the measurement. If an
attempt is made to measure a sample that drives the reading off scale high, move the black handle
into the bypass position immediately to dry the sensor.
4. Do not introduce dirty samples into the instrument. Filter contaminated or oily streams to prevent
contamination of the sensor and internal piping.
5. Insure plumbing connections are tight. A leak will introduce errors in the measurement,
6. Keep sample lines to measurement taps as short as possible using small diameter (¼”) tubing to
achieve the best response speed.
7. Use stainless steel, copper or PFA Teflon tubing for sample connections for best results.
8. Allow sufficient time to purge the new sample through the sample lines to insure a fresh sample is
provided to the analyzer. This may take a minute or two if the sample tap connection is mounted
directly to the pipe or several minutes if the sample line is necessarily longer to reach the source.
9. Keep good records of periodic measurements. This will allow better planning for maintenance of
process equipment and measurement practices.
2.4.3.1 Checking Dryer Performance
Gas dryers often vary in their ability to dry the gas at any given point in time. Spot checking a dryer can
often produce readings that vary depending on the load of gas flowing through it, the cycle or stage of
operation for the dryer and the condition of the dryer internal mechanical and or chemical elements.
Good record keeping and tracking the initial measurements for longer periods can be helpful in
determining the typical dryer performance in a specific system.

DewPro MMY245 Installation and Operation Manual
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2.4.3.2 Quality Assurance
Quality checks of gas supplies can be made easily with the MMY 245. The basis for the measurement
should be established prior to making any actual readings. Typically the readings for gas quality are
made in ppmv and the instrument can be configured to provide this information accurately. The
parameters of pressure are important to making any concentration measurement so the instrument can
be configured properly. A review of the quality specifications between the supplier and the user is
helpful to determine acceptable moisture measurement practice.
2.5 Instrument Setup / Programming
In addition to preparing the hardware for connection to process fittings, the analyzer should be checked
for the proper operation. Configuring the MMY 245 is made simple using a matrix format. The diagram
for the matrix is located on the rear panel of the analyzer (See Figure 5). The 10 X 10 matrix contains
all the operating parameters for properly displaying and calculating the correct value in the appropriate
unit of measure. The control functions for the outputs and interface connections are easily set by
moving through this matrix and selecting the appropriate values for each cell. The following section
describes the features and usage of the various matrix locations as they apply to the MMY245.
2.5.1 Matrix Orientation
The display of the DewProMMY245 shows the current matrix location at all times, using the vertical
(V or row) and horizontal (H or column) coordinates. (Note: A matrix programming card, similar to the
one shown in Figure 5 is mounted to the outside of the enclosure).
Example: The position for the unit of measure selection is location V0H1. (See Figure 5.)
Movement through the matrix is accomplished by using the “V” and “H” buttons to move to another
row or column. For example, beginning at V0 H0 and successively pressing “V”, leads the user to V1
H0, V2 H0, V3 H0, V4 H0, V5 H0, V6 H0, V7 H0, V8 H0, V9 H0 and back to V0
H0. At any location where a value may be changed by the user, the digit to be altered is selected using
the “+” and “-” buttons.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 12
MMY245 H0 H1 H2 H3 H4 H5 H6 H7 H8 H9
V0
Channel 1 Display
Moisture
Value
Select
Moisture
Unit
Display
Moisture
Minimum
Event
Display
Moisture
Maximum
Event
Reset
Moisture
Min/Max
Events
Output 1
at Fault
0=-0.1V
1=5.1V
2=hold
Display
Moisture
A/D
V1
Output 1
Scale
Td °C
0 V
Td °C
5 V
Td °F
0 V
Td °F
5 V
ppmv
0 V
ppmv
5 V
lbs/MMSC
F
0 V
lbs/MMSCF
5 V
g/m³
0 V
g/m³
5 V
V2
Output 1
Scale
g/kg
0 V
g/kg
5 V
% RH
0 V
% RH
5 V
P Td °C
0 V
P Td °C
5 V
P Td °F
0 V
P Td °F
5 V
V3
Channel 1
Setup
Pressure
Constant
in bar
Pressure Td
Constant
in bar
Output 1
Enable
0=Disable
Output 1
D/A Cal.
0 V
Output 1
D/A Cal.
5 V
V4
Channel 2 Display
2nd CH.
Value
Select
2nd CH.
Value
Output 2
at Fault
0=-0.1V
1=5.1V
2=hold
Temperature
A/D
V5 Scale
Output 2
Opt. Input
Tem p. °C
0 V
Temp. °C
5 V
bar
0 V
bar
5 V
Min. Input
Display
Value
Max. Input
Display
Value
Minimum
Input
Voltage
Maximum
Input
Voltage
Minimum
Output
Voltage
Maximum
Output
Voltage
V6
V7
Channel 2
Setup
Output 2
Enable
0=Disable
Output 2
D/A Cal
0 V
Output 2
D/A Cal
5 V
V8
Special
Double Pt.
Dewcomp
1=begin
Double Pt.
State
100=OK
Single Pt.
DewComp
1=begin
Single Pt.
State
100=OK
Battery
Capacity
Remaining
Auto-off
Tim e
Minutes
Input
Locking
50=Unlock
V9
Service
Display
Primary
Error Code
Display
Secondary
Error Code
Unit
ID
Software
Version
Reset
to Defaults
50=Reset
System
Reset
50=Reset
Location V4 H1
0 = Temperature °C
1 = Temperature °F
2 = Pressure psig
3 = Pressure psia
4 = Pressure bar
5 = Scaled Input
Voltage
6 = Td °C
7 = Td °F
8 = ppmv
9 = lbs/MMSCF
10 = g/m³
11 = g/kg
12 = RH
13 = Pressure Td °C
14 = Pressure Td °F
Location V0 H1
0 = Td °C
1 = Td °F
2 = ppmv
3 = lbs/MMSCF
4 = g/m³
5 = g/kg
6 = RH
7 = Pressure Td °C
8 = Pressure Td °F
Figure 5

DewPro MMY245 Installation and Operation Manual
GE General Eastern
2.5.2 Special Functions of the Push Buttons
(a) Reset to “Normal” Display
Pressing the “Home” button returns the user to V0 H0 (normal display). Pressing the “Home” button
again V4 H0 is displayed representing the temperature or the unit of measure selected in V4 H1. Pressing
“Home” repeatedly alternates the displayed unit between V0 H0 and V4 H0
(b) Display Only
Note that fourteen (14) matrix locations are for display only and may not be changed by the user (refer to
Figure 5). For convenience, input (or programming) fields have a flashing digit in the display, whereas
“display only” fields do not.
The “display only” fields are as follows:
V0 H0 = Display Moisture Value
V0 H2 = Display Moisture Minimum Event
V0 H3 = Display Moisture Maximum Event
V0 H8 = Display Moisture A/D
V3 H0 = Pressure Constant in bar (if pressure sensor option is installed)
V4 H0 = Display 2nd Channel Value
V4 H8 = Temperature A/D
V8 H1 = Double Point State 100 = ok
V8 H3 = Single Point State 100 = ok
V8 H5 = Battery Capacity Remaining (%)
V9 H0 = Display Primary Error Code
V9 H1 = Display Secondary Error Code
V9 H2 = Unit ID
V9 H3 = Software Version
2.5.3 Function Guide
Using the Matrix (refer to Figure 5).
The matrix is organized in functional families by rows. The following is a general description of these
functional families indicating the row in which they can be found.
Row Family of Functions
V0 Channel 1, selection of the moisture unit, fault events
V1/V2 Scaling the output 1 to a selected unit of measure for moisture
V3 Pressure constant, output 1 hardware set-up
V4 Channel 2, selection of second unit of measure i.e. temperature, second moisture unit
or scaled input
V5 Scaling of second output and option input
V7 Output 2 hardware set-up
V8 Special functions
V9 Service information
2.5.4 Matrix Field Details
Not all of the cells in the matrix are used. Below are descriptions for specific cells that are used to control
the operation of the instrument. Note: a portion of the V8 row will be explained in section 4 since this row
refers to the interface with the MMY 30/31 series transmitters.

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GE General Eastern 14
Note: To assist in setting a value in a cell, the cursor (flashing digit to be altered) can be moved from the
digit to digit, right to left, by pressing the Vand Hbutton simultaneously.
Cell Function
V0 H0 Displays moisture unit selected in V0 H1
V0 H1 Entering a number from 0 to 8 selects desired moisture unit displayed in V0 H0
(see table location V0 H1 on the matrix illustration). Note: Selecting 7 or 8 displays
the pressure dew point in V0 H0 as a function of the pressure value entered in V3
H1. Example: The process pressure is 100 bar and is to be measured by reducing the
gas sample to the MMY 245 to atmospheric pressure. If the pressure dew point
temperature is desired, entering 100 bar in V3 H1 the dew point for 100 bar is
calculated and displayed in V0 H0 or V4 H0 (second unit of measure) if selected
from table location V4 H1 (see matrix illustration).
If a concentration unit, i.e. 2 = ppmv, 3 = lbs/MMSCF, 4 = g/m3is selected, inlet
pressure can be compensated for up to 10 bar. The actual sample pressure must be
entered in bar(a) in V3 H0. This pressure value covers process pressures up to 10
bar(g) that can be connected directly to the MMY 245 system (10 bar(g) maximum).
Dynamic pressure compensation can be accomplished if the optional pressure sensor
is installed (10 barg max.).
V0 H2 Displays the lowest moisture value measured since the unit was reset using V0 H4,
new batteries were installed, system reset performed using V9 H9, or unit of
measure selection is changed.
V0 H3 Displays the highest moisture value measured since the unit was reset using V0 H4,
new batteries were installed, system reset performed using V9 H9, or unit of
measure selection is changed.
V0 H4 Resets the event memories of V0 H2 and V0 H3 by pressing the + button
V0 H7 Fault status for output 1 is selected with 0 setting the output to -0.1 V, 1 setting the
output to 5.1 V and 2 holding the output to the last measured value with the
occurrence of a memory or output error.
V0 H8 Displays the raw digital value corresponding to the moisture content, and can be
verified using the calibration table supplied with the instrument. This value is equal
to the “counts”/10 as illustrated on the calibration data sheet furnished with the
instrument.
V1 H0-
9 and
V2
H0-7
Scaling the moisture output. The low moisture value is assigned to 0 V, the high
moisture value is assigned to 5 V.
V3 H0 A pressure value between 0.01 and 99.99 bar can be entered correcting concentration
units (see explanation under V0 H1).
V3 H1 A pressure value from 0.1 to 999.9 bar can be entered to calculate the process
pressure dew point (see explanation under V0 H1).
V3 H7 Enables output 1 by entering a digit other than 0, disables the output 1 by entering a
0.
V4 H0 Displays the second unit of measure that normally would be the temperature.
However, any other unit (see table location V4 H1 on the matrix illustration) can be
assigned to this matrix field choosing a number from 0 to 14 in V4 H1.
V4 H1 Selects the second unit of measure displayed in V4 H0 from the table in location V4
H1 on the matrix illustration.

DewPro MMY245 Installation and Operation Manual
GE General Eastern 15
Cell Function
V4 H7 Fault status for output 2 is selected with 0 setting the output to -0.1 V, 1 setting the
output to 5.1 V and 2 holding the output to last valid measured value with the
occurrence of a measuring error.
V4 H8 Displays the raw digital signal corresponding to the temperature value. This value is
only used for troubleshooting at the request of a factory technician.
V5 H0 Scaling the output the low temperature value is assigned to 0 V.
V5 H1 The high temperature value is assigned to 5 V.
V5 H8 Scaling the output voltage to either 0 or 1 to 5 Volts, the low value is entered here (0
V = minimum).
V5 H9 Scaling the output voltage to a voltage up to 5 V, the high value is entered here (5 V
= maximum).
V7 H7 Enables output 2 by entering a digit other than 0, disables the output 2 by entering 0.
V8 H5 Displays the remaining battery capacity in %. It is recommended to renew the
batteries when the display is <15%.
V8 H6 The number programmed determines the operating time in minutes after which the
unit will turn itself off to save battery energy. If set to zero the instrument will
operate in a continuous mode. The range available is 1 to 19999 minutes.
V8 H9 Selecting a number other than 50 will lock the matrix, values in the matrix fields can
be viewed but not changed inadvertently or to avoid tampering by unauthorized
persons. Entering 50 unlocks the matrix allowing changes in matrix fields.
V9 H0 In case of a fault condition, an error code is displayed enabling the user to identify
any software errors when communicating to the factory technicians. See the trouble
shooting section for details.
V9 H1 The error preceding the current error displayed in V9 H0 is indicated enabling the
user to identify any hardware errors when communicating to the factory technicians.
V9 H2 The instrument is identified by a series ID number that currently is 150.
V9 H3 The software version implemented is displayed.
V9 H5 Entering 50 enables the user to reset the instrument to factory defaults without
affecting the calibration data. This function may help if the user feels they got lost
while setting function values.
V9 H9 Entering 50 resets the system after calibration equaling a power off and on. This is
merely a factory or expert function.
2.5.5 Special Output and Input Functions
Outputs can be used for temporary, unmanned, monitoring of moisture in a process or environment by
connecting the MMY 245 to a recorder or data logger. The outputs can be scaled using the matrix to allow
study of moisture over a specific range for a period of time.
The MMY 245 can also accept inputs from external transmitters for display locally on the unit. This feature
can be useful in the field to monitor process information locally. The external transmitter signal can be
connected to the MMY 245 and the signal scaled to allow that scalable parameter to be displayed in
addition to the moisture value.
Cell Function
V3 H8 Calibrates the output 1 hardware at 0 V: connecting a voltmeter to the output the
displayed number can be increased or decreased using the + and - button to adjust the
voltmeter reading to 0 V (Value is around 500). This is factory calibrated.

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GE General Eastern 16
Cell Function
V3 H9 Calibrates the output 1 hardware at 5 V: connecting a voltmeter to the output the
displayed number can be increased or decreased using the + and - button to adjust the
voltmeter reading to 5 V (Value is around 2500). This is factory calibrated.
V5 H2 Scaling the output the low pressure value is assigned to 0 V. The value indicated will
assign the “0” volt output to track the pressure transmitter. It will also function to
respond to the pressure constant if no optional pressure sensor is installed.
V5 H3 The high pressure value is assigned to 5 V. The value indicated will assign the “5”
volt output to track the pressure transmitter. It will also function to respond to the
pressure constant if no optional pressure sensor is installed.
V5 H4 Using the scaled input with any sensor (e.g. oxygen sensor) the low value to be
displayed is entered here.
V5 H5 Using the scaled input with any sensor (e.g. oxygen sensor) the high value to be
displayed is entered here.
V5 H6 The minimum voltage (0 V = minimum) external sensor electronics would supply is
entered here in Volts.
V5 H7 The maximum voltage (5 V = maximum) external sensor electronics would supply
is entered here in Volts.
V7 H8 Calibrates the output 2 hardware at 0 V: connecting a voltmeter to the output, the
displayed number can be increased or decreased using the + and - button to adjust the
voltmeter reading to 0 V (Value is around 500). This is factory calibrated.
V7 H9 Calibrates the output 2 hardware at 5 V: connecting a voltmeter to the output the
displayed number can be increased or decreased using the + and - button to adjust the
voltmeter reading to 5 V (Value is around 2500). This is factory calibrated.
2.5.6 Interconnection
The MMY 245 can be powered from an external DC power supply and can provide voltage outputs for
recording purposes. The paragraphs below describe these functions.
WARNING! The MMY 245 is not designed to be connected to either an external
power supply or external signals for inputs or outputs in hazardous or electrically
classified areas.
2.5.6.1 External Power Option
The DewProMMY245 can be powered with 6-12 VDC using the power and output cable P/N 63002013.
This cable will allow connection of the DC power using the Red (+) and Black (-) wires per the drawing
MSY35C in the appendix of this manual.
WARNING! The MMY 245 has a maximum voltage specification of 12 VDC.
Connecting the unit to a higher voltage could cause damage to the unit and will void
the warranty.
2.5.6.2 External Scalable Input Option.
The DewProMMY245 can display an external analog input using the power and output cable P/N
63002013.
2.5.6.3 Voltage Inputs
The cable P/N 63002013, will allow connection of the DC 0/1-5 VDC signal using the Orange (+) and
Black (-) wires per the drawing MSY35C in the appendix of this manual. This input can be scaled and

DewPro MMY245 Installation and Operation Manual
GE General Eastern 17
displayed using the procedures for V5 H4, V5 H5, V5 H6, and V5 H7. See the section 2.5.5 above
titled 2.5.5 Special Output and Input Functions.
2.5.6.3.1 Current Inputs
When reading a 4-20 mA signal from an external device, use a 249 Ωresistor across the wires for a 1-5
VDC input.
Example Conditions:
1. Input device is a MMY30 with –90 to +10 as the 4-20mA span settings.
2. Sense resistor is 249 Ohms
3. Output voltage of MMY245 must span 1 to 5 volts given the 4-20mA span of the MMY30.
Required Settings:
1. V5 H4 = -90
2. V5 H5 = 10
3. V5 H6 = 1.00V (4mA * 249 Ohms = 0.996V ≈1.00V)
4. V5 H7 = 4.98V (20mA * 249Ohms = 4.98V)
5. V5 H8 = 1.00
6. V5 H9 = 5.00
Therefore as the 4-20mA signal is sensed by the 249 Ohm resistor as a voltage between 1.00 and 4.98 volts,
the display in matrix location V4 H0 will show a linear value between –90 and +10 with a voltage output
between 1.00 and 5.00 volts to match.
2.5.6.4 Output connections
The DewProMMY245 can provide 0-5 VDC outputs for recording or logging the readings using the
power and output cable P/N 63002013. This cable will allow connection of the DC power using the Green
(+ for output 1) and Black (-) or the White (+ for output 2) and Black (-) wires per the drawing MSY35C in
the appendix of this manual. The output impedance is 100 Ω. This must be connected to a recorder or
logger with an input resistance of at least 20 KΩto provide 0.5% accuracy. A higher input impedance is
recommended for better signal accuracy. These outputs are scaled and referenced to specific units of
measure using V1 H0, through V2 H7 for output 1, and V5 H0 through V5 H4 for output 2. See the
section 2.5.5 above titled 2.5.5 Special Output and Input Functions.
3 Troubleshooting
Field maintenance consists of keeping the instrument clean replacing the batteries when the unit indicates
they are low (see V8 H5). In addition, monitoring the reading after leaving the handle in the bypass
position over night will provide an indication of how well the desiccant can dry down the sensor. If this
reading is above –30°C dew point, return the unit to the factory for desiccant replacement and service.
3.1 General Troubleshooting Practice
Troubleshooting will be helpful in case the instrument does not perform and has an error indication on the
display. This troubleshooting guide is limited to the function of the unit and is not intended to address
questionable readings where there is no error code present. Suspected errors in readings should be dealt
with first by insuring all connections are leak free and that the unit of measure is correctly set. The pressure
compensation mode should be verified that it is set correctly for the application. After these items are
verified to be correct, and if the unit still produces questionable readings, contact the General Eastern
factory field service department by calling 800-33HUMID (334-8643) for further assistance.
General Troubleshooting Guide

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GE General Eastern 18
Problem Cause Remedy
Display reads high with handle in the bypass
position.
Desiccant is
expended
Contact Factory
Display has a lightning bolt symbol appears
steady in the display and reading is missing or
doesn’t make any sense.
Error has occurred
or instrument is off-
scale
1. Connect to a dry gas
source
2. Consult Error Code Chart
3. Contact the factory
Display reads fine but the lightning bolt symbol
is flashes.
Low Batteries Change batteries.
3.2 Error Codes
The following procedure is designed to narrow the search for a problem with the MMY 245. It will not
provide answers regarding all questionable readings since many external influences such as leaks, can
affect the actual readings properly processed and displayed on the unit. Error codes will remain until the
condition is cleared. They will clear automatically when the condition causing the error disappears. For
specific remedies, contact the General Eastern factory field service department by calling 800-33HUMID
(334-8643) for further assistance.
Software errors V9 H0
Error Description
0 No Error
1* Dew point < -100C
2* Dew point > 20C
4 Voltage output on CH1 scaled to < 0V
8 Voltage output on CH1 scaled to > 5V
16 Temperature out of range
64 Voltage output on CH2 scaled to < 0V
128 Voltage output on CH2 scaled to > 5V
* An error indicating that the dew point is both < -100C and > 20C indicates that the output on CH1 cannot
be calculated because of an error reading the temperature.
Hardware errors V9 H1
Error Description
0 No error
1 Low battery
2 Sensor shorted
4 Sensor Open
Under many situations more than one error can occur at a given time. To determine which error(s) are
active, use the following algorithm:
1. Find the largest error number on the above table that is smaller than or equal to the error indicated on
the MMY245.
2. Note this error and subtract the value from the MMY245 error code. Return to step one using the
remainder. Continue this process until your remainder is zero.
For example if the error indication is 80 then:
1. 64 is the largest error that fits in 80 so “Voltage output on CH2 scaled to < 0V” is true. Now subtract
64 from 80. The remainder is 16.
16 is the largest error that fits in 16 so “Temperature out of range” is true. Now subtract 16 from 16. The
remainder is 0. This indicates there are no more errors occurring.