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Relative Humidity – Transmitters

GE Sensing’s HygroTrac™ takes moisture monitoring to the next level with the launch of the Protimeter HygroTrac™ The HygroTrac™ is a wireless system for monitoring environmental conditions remotely in buildings. Small HygroTrac™ wireless sensors are installed throughout a building to monitor relative humidity, temperature and moisture content. Readings are transmitted to the data acquisition gateway that is connected to a dedicated and secure web server via Ethernet or phone line. Data can be viewed virtually live on the web site as well alarms set that send email warnings to your pc or mobile phone by way of text messages.


HumiTrac™ , GE’s next generation relative humidity and temperature transmitter designed to serve the building automation/HVAC market, as well as a wide variety of general purpose relative humidity monitoring applications. All models incorporate a NIST traceable, field-replaceable sensor tip, a rugged capacitive sensing element capable of full-scale 0 to 100% RH measurement and a host of field configurable output options.

  • NIST-Traceable, field-replaceable sensor
  • NIST-Traceable factory calibration
  • User-selectable RH & temperature outputs
  • Robust, proven capacitive sensor technology
  • Attractive and rugged packaging
  • 2% or 5% RH accuracy
  • NIST certification available
  • Versatile temperature measurement
  • Low cost of ownership
  • Two-year warranty

Environmental Conditions

Operating Range
  • -40°F to 140°F (-40°C to 60°C)
  • 0% to 99% RH (non-condensing)
Storage Temperature
  • -67°F to 185°F (-55°C to 85°C)


Sensing Element
  • Capacitive polymer sensor
Accuracy at 71.6°F (22°C)
  • ±2% version: ±2% 10 to 90% RH ±5% 0 to 10% & 90-99% RH
  • 3% version: ±3% @ 10 to 90% RH
  • 5% version: ±5% RH @ 0 to 99% RH *Includes hysteresis, linearity and repeatability
Long Term Stability
  • Less than 1% drift per year, typical
Temperature Effect**
  • Delta %RH = (0.0014 x %RH + 0.1325) x T°C – (0.0317 x %RH + 3.0876)
  • See accuracy statement
  • See accuracy statement
  • 70%RH 1h ->90%RH 1h ->30%RH, Vair = 2m/sec)
Signal Outputs
  • 4 to 20mA, 0 to 5V or 0 to 10V (user selectable)
**Not applicable to signal-conditioned temperature units.

Temperature-Direct Connection Thermistor

Sensing Element
  • 10K S thermistor at 77°F (25°C)
  • 3K S thermistor at 77°F (25°C)
Signal Output
  • Direct connection, user selectable between 3K or 10K
  • Refer to DC95F103W (10K) and DC95F302W (3K) from GE

Temperature-Signal Conditioned PRTD

Calibration Accuracy at 71.6°F (22°C)
  • ±0.5°F (±0.3°C)
Long Term Stability
  • Less than 0.2°F drift per year
Sensor Interchangeability
  • ±0.5°F (±0.3°C)
Signal Outputs
  • 4 to 20mA, 0 to 5V or 0 to 10V (user selectable)

Power Requirements

Supply Voltage
  • 12 to 30 VDC
Maximum Load (current output only)
  • S = Supply Voltage-10/0.02

VAC/building controls

  • Energy Management Systems (EMS)
  • Enthalpy control
  • Indoor Air Quality (IAQ)
  • Clean rooms
  • Museums/archives
  • Hospitals/labs
  • Refrigeration control
  • Pharmaceutical
  • Animal rooms
  • Food Storage

DewPro MMR 101

A high-temperature loop-powered moisture and temperature transmitter with two current loops for in-line measurement.

  • Operating temperature up to 150°C (302°F)
  • 0 to 100% relative humidity
  • Dew point 0°C to 150°C (32°F to 302°F)
  • 4 to 20 mA loop-powered
  • Second isolated 4 to 20 mA loop for temperature measurement (patented)
  • 1/2″ MNPT or other process connections
  • Capacitive polymer sensor
  • Platinum RTD temperature sensor
  • Microprocessor electronics in NEMA 4X enclosure (IP 66)
  • IS or x-proof FM approved

EHRH Waterproof

The Model EHRH Relative Humidity Transmitter is a waterproof RH sensing element and package which is ideally suited for monitoring relative humidity in high RH/harsh environment applications or where washdowns are required. The unit is designed for continuous monitoring of relative humidity and temperature and is available in +/- 2% accuracy.

  • Waterproof Sensing Element and Housing
  • Compact Transmitter with Built-in Sensor
  • Bulk Polymer Resistance RH Sensor
  • Resistant to Contamination
  • Thermistor Temperature Measurement
  • Temperature Compensation

coming soon

coming soon

coming soon

DewPro MMR30

The DewPro MMR30 is a compact, mid-range moisture transmitter probe designed specifically for refrigeration dryer manufacturers and users. The MMR30 measures dew point at line pressure or atmospheric pressure and installs easily on a dryer outlet header. The MMR30 uses a proven polymer capacitive sensor to provide a measurement range of -15°C to +85°C (+5°F to +185°F) with ± 1.0°C ( ± 1.8°F) accuracy. The instrument can be configured and controlled with a PC using DewPro Communication software. With this software, the user can set the dew point range, adjust the loop content and read the dew point.

  • 4 to 20 mA loop powered
  • Simple two-wire connection
  • Fast response times
  • Trouble-free indoor or outdoor mountings
  • Internal bypass system
  • Eliminates sample system
  • Measures at line pressure

coming soon

coming soon

coming soon

MMR 31 Loop Powered Moisture Analyzer

The MMR 31 Loop Powered Moisture Analyzer represents a simple, cost-effective solution for mid-range moisture measurements. Whether you need to improve product economy, increase product quality, maintain comfort levels, or preserve the properties of stored foods or other supplies, the MMR31 allows application flexibility. The MMR31 can also be quickly recalibrated in the field using salt bottles. A second, isolated loop for temperature is optional.

  • Economical, versatile analyzer measures relative humidity, dew point, absolute humidity, mixing ratio
  • Proven polymer capacitive sensor for fast responseand calibration stability
  • 0 to 100% RH or dew point measurement range of -15°C to +85°C
  • Simple, two-wire connection (4 to 20 mA)
  • Easy mounting with standard compression fittings
  • Simple field recalibration with salt bottles
  • NEMA 4X (IP67) Enclosure