Humidity and Temperature Meter Series HMT330

Measure humidity in harsh environments with the best-in-class instrument you can truly depend on. The Vaisala HUMICAP® Humidity and Temperature Transmitter Series HMT330 with 10-year warranty* is designed for demanding industrial applications where stable measurements and extensive customization are essential.

There are six models to choose from:

  • HMT331 for wall mounting
  • HMT333 for duct mounting and tight spaces
  • HMT334 for high pressures up to 100 bar and vacuum conditions
  • HMT335 for high temperatures
  • HMT337 for high humidity and meteorological applications
  • HMT338 for pressurized pipelines up to 40 bar

The instrument can be quickly tailored to meet the specific needs of each individual application and is pre-configured for each delivery.

Click here to download bid specs for USA.


  • Full 0 … 100 %RH measurement, temperature range up to +180 °C (+356 °F) depending on model
  • Pressure tolerance up to 100 bar depending on model
  • Excellent performance in harsh conditions; good chemical tolerance
  • Corrosion-resistant IP65/IP66 housing
  • Traceable calibration for measurement and analog outputs (certificates included)
  • RS232/485/422 LAN
  • Modbus protocol support (RTU/ TCP)
  • Optional graphical display and keypad for convenient operation
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Key Benefits

Reliable and stable
Accurate and stable measurement even in demanding conditions gives reliable data. The construction of the transmitter is suitable for the heavy duty in industrial applications.
Configurable and ready for installation
The product is assembled and configured to your needs, delivered within days to your facility, and fully ready for installation. The user interface is multilingual and available in English, German, French, Japanese and Chinese.
10-year warranty
We offer a 10-year warranty on new HMT330 transmitters that are calibrated annually at the Vaisala Service Center. This warranty program is available to all customers for units purchased from January 2014 onwards and requires no sign-up.

Watch the video

Vaisala HUMICAP® Humidity and Temperature Transmitter Series HMT330


Datasheet (8.57 MB)

  • Proven Vaisala HUMICAP Performance
  • Wide Range of Installation Options
  • Graphical Display of Measurement Data and Trends for Convenient Operation
  • Versatile Outputs and Data Collection

Manual (4.19 MB)

  • General information
  • Product overview
  • Installation
  • Operation
  • Modbus
  • Maintenance

Product Resources

Register to start the Vaisala Humidity Calculator

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Download a Free Humidity Guide for Smart Industries

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Success Stories

Success story
| May 31st 2017

Mona Lisa Preserved by Vaisala

“I am sure you know of the Mona Lisa, known as La Joconde in French, one of the most popular works of art in the world. You also know that it can be found in the world-renowned Louvre Museum in Paris. But what you may not know is that Vaisala helps preserve the Mona Lisa by measuring the stability of the humidity and temperature environment within its glass vitrine.”
Jean-Francois Bore, Application Sales Engineer, Vaisala
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Success story
| Jan 3rd 2018

Vaisala HUMICAP® Sensor for Measuring Relative Humidity

Until the early 1970s, hair hygrometers were commonly used in radiosondes. At that time, reliable humidity measurement was an unresolved challenge and to solve this, Vaisala began developing a new type of humidity sensor using semiconductors and thin-film materials. The revolutionary HUMICAP humidity sensor was introduced two years later, in 1973, at CIMO VI congress.
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Success story

Optimized drying saves you energy and costs

Save energy and reduce costs by monitoring the humidity in your processes to avoid over-drying products and wasting energy.

We have developed this drying simulator to help everyone understand the way exact humidity measurements can lead to more efficient energy use and higher yields.

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