GE Sensing MMR31 Specifications

GE

Sensing

Features

DewPro

®

MMR31

Moisture Transmitter

The DewPro MMR31 loop-powered moisture transmitter
represents a simple, cost-effective solution for mid-range
moisture measurements. The DewPro MMR31 uses a
proven polymer capacitive sensor to provide a
measurement range of 0 to 100% RH with an accuracy
of ±2% in the range of 0 to 90% and ±3% in the range of
90 to 100%. A patented second isolated loop for
temperature measurement is also available. The optional
integrated display with user interface provides full
programming and diagnostic capability.

The DewPro MMR31 provides a wide range of process
humidity measurements, including relative humidity, dew
point temperature, absolute humidity, and mixing ratio.
These key parameters will help monitor and control
critical processes. Whether you need to improve product
economy, increase product quality, maintain comfort
levels, or preserve the properties of stored foods or other
supplies, the DewPro MMR31 allows application flexibility.

DewPro MMR31 is a General Eastern
product. General Eastern has joined
other GE high-technology sensing
businesses under a new name

_

GE Industrial, Sensing.

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• Loop-powered, 4 to 20 mA transmitter

• Proven polymer capacitive sensor for fast response
and calibration stability

• Trouble-free indoor or outdoor mounting

• Simple field recalibration with salt bottles

• Microcontroller electronics in Type 4X/IP67 enclosure

Options

• Integral display with user interface

• English or metric fittings

• External display available with loop-powered supply
and alarm contacts

• Second isolated loop (patented) for temperature

• Wall mount kit

Sensing Element

Silicon-based polymer, capacitance principle, IC electronics

RH Range

0 to 100%

RH Accuracy at 77°F (25°C)

±2% in the range of 0% to 90%
±3% in the range of 90% to 100%

Dew Point Range

5°F to 185°F (-15°C to 85°C)

Dew Point Accuracy

±1.8°F (±1°C) above 32°F (0°C) dewpoint @ 25°C

Operating Temperature Range

Process: 5°F to 185°F (-15°C to 85°C); temperature signal
available with second loop
Electronics: -40°F to 185°F (-40°C to 85°C)

Temperature Accuracy

±0.9°F (±0.5°C)

Absolute Humidity Range

1 to 350 g/m

3

Mixing Ratio Range

1 to 830 g/kg

Maximum Operating Pressure

250 psia (17 bar)
Filter element: 100 microns sintered stainless steel

Outputs

Loop current 4 to 20 mA, 16

:A resolution. Optional output

for temperature

Hardware Selectable Units

% RH, dew point temperature in °F or °C, absolute humidity
in g/m

3

, or mixing ratio in g/kg

Optional Display

Four-digit numeric display with bar graph and matrix
position indication. Four user interface keys for unit
selections, output adjustments and ranging.

Power Supply

24 VDC nominal, 12 to 30 VDC range

Protection

Type 4X/IP67

Probe Tube

316 stainless steel, 1/2 in (12.7mm) diameter, insertion
length 3.0 in (75mm) to 5.9 in (150mm), adjustable

Typical Probe Mounting

1/2 in tube x 1/2 in NPT-M or 1/2 in tube x G 1/2
compression fitting

Weight

3.3 lb (1.5 kg)

European Compliance

Complies with EMC Directive 89/336/EEC and
PED 97/23/EC for DN<25

GE

Sensing

DewPro MMR31
Specifications

5.44 in

(138.0 mm)

11.49 in

(291.8 mm)

3.11 in

(79.0 mm)

6.43 in

(163.3 mm)

Epoxy-coated
cast
aluminum
housing that
meets
Type 4X/IP67
requirements

M20 or
1/2 in
NPT
conduit
or
cable
gland

Sintered
end cap

5.06 in

(128.5 mm)

.50 in

(12.7 mm)

©2005 GE. All rights reserved.
920-063B

All specifications are subject to change for product improvement without notice.
DewPro®is a registered trademark of GE. GE®is a registered trademark of General
Electric Co.

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www.gesensing.com

DewPro MMR31 with optional display