DewPro® is a GE General Eastern product. GE General Eastern has joined other GE high-technology sensing
businesses under a new name—GE Sensing.
November 2005
WarrantyEach instrument manufactured by GE Infrastructure Sensing, Inc. is
warranted to be free from defects in material and workmanship.
Liability under this warranty is limited to restoring the instrument to
normal operation or replacing the instrument, at the sole discretion of
GE Infrastructure Sensing, Inc. Fuses and batteries are specifically
excluded from any liability. This warranty is effective from the date of
delivery to the original purchaser. If GE Infrastructure Sensing, Inc.
determines that the equipment was defective, the warranty period is:
• one year for general electronic failures of the instrument
• one year for mechanical failures of the sensor
If GE Infrastructure Sensing, Inc. determines that the equipment was
damaged by misuse, improper installation, the use of unauthorized
replacement parts, or operating conditions outside the guidelines
specified by GE Infrastructure Sensing, Inc., the repairs are not
covered under this warranty.
The warranties set forth herein are exclusive and are in lieu of
all other warranties whether statutory, express or implied
(including warranties of merchantability and fitness for a
particular purpose, and warranties arising from course of
dealing or usage or trade).
Return PolicyIf a GE Infrastructure Sensing, Inc. instrument malfunctions within the
warranty period, the following procedure must be completed:
1. Notify GE Infrastructure Sensing, Inc., giving full details of the
problem, and provide the model number and serial number of the
instrument. If the nature of the problem indicates the need for
factory service, GE Infrastructure Sensing, Inc. will issue a RETURN
AUTHORIZATION number (RA), and shipping instructions for the
return of the instrument to a service center will be provided.
2. If GE Infrastructure Sensing, Inc. instructs you to send your
instrument to a service center, it must be shipped prepaid to the
authorized repair station indicated in the shipping instructions.
3. Upon receipt, GE Infrastructure Sensing, Inc. will evaluate the
instrument to determine the cause of the malfunction.
Then, one of the following courses of action will then be taken:
• If the damage is covered under the terms of the warranty, the
instrument will be repaired at no cost to the owner and returned.
• If GE Infrastructure Sensing, Inc. determines that the damage is not
covered under the terms of the warranty, or if the warranty has
expired, an estimate for the cost of the repairs at standard rates
will be provided. Upon receipt of the owner’s approval to proceed,
the instrument will be repaired and returned.
Upon receipt of the DewPro MMY30, 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 MMY30
• Installation and Operation Manual
• Calibration Certificate
Compare the last five numbers or letters on the model number (on the
product label shown in Figure 1-1 below) with the product structure
(see below) to ensure you have received everything you ordered.
Figure 1-1: DewPro MMY30
Product Structure Certification/Approvals:
R Standard (not certified)
A FM IS C1. I, II, III: Div. 1; Grps.A-G
B FM XP Cl.1, Div. 1; Grps. A-D
C FM Cl.1, Div. 2, Grps. A-D
Cl. II, III, Div. 1, Grps. E-G
S Other
Process Connection:
1 ½” MNPT (1/4” tube fitting if B, C or D is selected below)
2 G ½ (6 mm tube fitting if B, C or D is selected below)
S Other
General System Information1-1
November 2005
Product Structure (cont.)Orifice Configuration:
A Inlet: None; Outlet: Orifice, with ¼” FNPT
B Inlet: None; Outlet: Orifice, with (6 mm) ¼” tube fitting
C Inlet: None; Outlet: None, with (6 mm) ¼” tube fitting
D Inlet: Orifice; Outlet: None, with (6 mm) ¼” tube fitting
S Other
Enclosure Conduit:
1 M20 X 1.5 F with cable gland
2 M20 X 1.5 F with 1/2” FNPT adaptor
S Other
Output Configuration/Dewpoint Range:
A Td -90 °C to +10 °C (-130 °F to +50 °F), no display, error 22 mA
B Td -90 °C to +10 °C (-130 °F to +50 °F), no display, error Hold
C Td -90 °C to +10 °C (- 130 °F to +50 °F), no display, error 3.6 mA
D 0-100 ppm
E 0-100 ppm
F 0-100 ppm
G With integral display/user interface
H With integral display/user interface, includes moisture units
Lbs/MMSCF, natural gas
S Other
1 bar, no display, error 22 mA
v
1 bar, no display, error Hold
v
1 bar, no display, error 3.6 mA
v
1-2General System Information
November 2005
Introduction
Unit DescriptionThe DewPro MMY30 trace moisture transmitter (shown in Figure
1-2 below) is a loop-powered dewpoint measuring device. The
transmitter includes a sensor element, a flow chamber, a weatherproof enclosure, microprocessor electronics, and assorted fittings, all
in a compact assembly. In most cases, either the inlet or outlet port
includes an orifice to regulate the flow. The placement of this orifice
determines whether the dew point measurement is done at process
(line) pressure (outlet orifice), or at atmospheric pressure (inlet
orifice). A 2 micron sintered inlet filter prevents particles from
entering the device.
Optional Display/
User Interface
The optional display/user interface feature allows the DewPro to be
configured to the user's specifications. See Chapter 4 for more
information.
Figure 1-2: DewPro MMY30 Transmitter
General System Information1-3
November 2005
Theory of Operation
4 to 20 mA LoopThe DewPro MMY30 microprocessor controlled electronics operate
with a DC voltage supply from 12 to 28 VDC. At the nominal 24 V
DC supply, the maximum loop resistance is 600 Ohm. The signal is
represented by the 4 to 20 mA loop current and is directly
proportional to the dewpoint range in °C or °F. In the standard range,
4 mA corresponds to -90°C (-130°F) and 20 mA to +10°C (+50°F)
dewpoint temperature.The optional unit of measure is ppm
standard range 0-100 ppm
.
v
in the
v
BypassIn dryer applications, the moisture sensor performs best when
mounted in a bypass. The built-in bypass of the DewPro eliminates
costly hardware associated with traditional sampling methods. The
DewPro installs simply into the process with its G ½ or ½” MNPT
threaded connection.
Planar SensorThe heart of the MMY30 is the planar sensor element. It incorporates
a superior aluminum oxide sensor that provides longer calibration
stability, excellent corrosion resistance, and improved speed of
response. The sensor, mounted on a ceramic substrate, also has a
reduced temperature coefficient.
CalibrationEach DewPro is factory calibrated against precise NIST certified
moisture references and has an accuracy of ±2°C dewpoint at 25°C
temperature. For field validation, GE Sensing offers a unique
validation device. The MMY245 field validator connects to the
DewPro on site and offers a one-point or two-point correction.
1-4General System Information
November 2005
DimensionsChoose a mounting location which allows enough clearance for the
use of tools and for connection of the field validator. Figure 1-3
shows the dimensions of the standard DewPro, and Figure 1-4 shows
the DewPro with the optional display/user interface.
Figure 1-3: Standard DewPro Dimensions
Figure 1-4: Dimensions for DewPro with Optional Display/