DewPro® MMY31
Dew point transmitter

The DewPro MMY31 measures dew point or ppmv in gases.
It is a cost-effective, loop-powered dew point transmitter
designed for “in-line” installation where trace moisturemeasurement is required. The planar aluminum oxide sensor
provides excellent corrosion resistance, longer calibration
stability, quick response times, and an exceptionally low
temperature coefficient.

Options

The DewPro MMY31 mounts directly in-line in your processgas, where a bypass installation is not appropriate. It iseasily installed via a variety of adjustable insertion length
compression fittings. The optional integrated display withuser interface provides full programming and diagnostic
capability.

• External display available with loop-power supply andalarm contacts

Applications include glove boxes, environmental chambers,
test chambers, and other locations where direct insertion isrequired.

Features• Loop-powered, 4 to 20 mA transmitter• Fast response planar aluminum oxide sensor• Trouble-free indoor or outdoor mounting• Field validation with the MMY245 moisture analyzer• Microcontroller electronics in Type 4X/IP67 enclosure• Integrated display with user interface• FM approved intrinsically safe/explosion-proof, Class I,II,III,
Division 1 and 2, Groups A,B,C,D,E,F&G hazardous (classified)locations• English or metric fittings

DewPro MMY31 specifications
Sensing element

5.56 [141]Planar aluminum oxide sensor

3.22 [82]Measurement range-130°F to 50°F (-90°C to 10°C) dew point temperature; 0 to 10
ppmv, 0 to 1000 ppmv (fully adjustable with integral display)

M20 or 1/2 in.
NPT conduit orcable gland

Recommended recalibration cycle
12 months, depending on the application
Calibration accuracy±3.6°F (±2°C) dew point at 77°F (25°C)
Maximum sensor relative humidity
50% at dew point temperatures >32°F (>0°C)
Operating temperature range

Epoxy-coatedcast aluminum
housingthat meets
Type 4X/IP67
requirements

9.66 [246]

Process: -40°F to 122°F (-40°C to 50°C)

6.16 [156]Electronics: -40°F to 185°F (-40°C to 85°C)
Element filter

Optional
sintered endcap

100 micron, sintered stainless steelStandard operating pressure
0 to 1750 psig (0 to 120 bar, 12 MPa)
Helium leak-rate<10-6 mbar/s
Output4 to 20 mA loop-powered, 16 μA resolution
Electronics
Microcontroller operated
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

0.5 [12.7]
DewPro MMY31 with display option

Protection
Type 4X/IP67
Weight3.3 lb (1.5 kg)
Probe tube
316 stainless steel, 1/2 in. (12.7 mm) diameter, insertion length
2 in. (50 mm) to 3.5 in. (90 mm)
Typical probe mounting
1/2 in NPT-M, 3/4 in NPT-M, 3/4-16 O-ring, G 1/2 compression
fittings. Others available, consult factory.
European compliance
Complies with EMC Directive 89/336/EEC and PED 97/23/EC
for DN<25
Optional certifications/approvals• FM IS Class I,II,III, Division 1, Groups A,B,C,D,E,F&G, T5• FM XP-IS Class I, Division 1, Groups A,B,C&D, T5• FM NI Class I, Division 2, Groups A,B,C&D, T4A DIP Class II,III,Division 1, Groups E,F&G, T5• ATEX II 3G EEx nA IIC T4

Panametrics, a Baker Hughes Business, provides solutions inthe toughest applications and environments for moisture,oxygen, liquid and gas flow measurement. Experts in flaremanagement, Panametrics technology also reduces flareemissions and optimizes performance.
With a reach that extends across the globe, Panametrics’
critical measurement solutions and flare emissions
management are enabling customers to drive efficiency
and achieve carbon reduction targets across criticalindustries including: Oil & Gas; Energy; Healthcare; Water andWastewater; Chemical Processing; Food & Beverage andmany others.
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