Relative Humidity and Temperature Probe HMP7

for high humidities

DNV - Type Approved Product

Vaisala HUMICAP® Humidity and Temperature Probe HMP7 is designed for applications which involve constant high humidity or rapid changes in humidity such as drying and test chambers, combustion air and other humidifiers and meteorological measurements where measurement performance and chemical tolerance are essential. The HMP7 is part of the Indigo product family and compatible with Indigo500, Indigo300 and Indigo200 series transmitters and free Insight PC Software.

Click here to download bid specs for USA.


  • RH accuracy up to 0.8 %RH, Temperature accuracy up to 0.1 °C (0.18 °F)
  • Temperature measurement range -70 ... +180 °C (-94 ... +356 °F)
  • Vapor and pressure proof construction
  • Probe and sensor warming functions minimize condensation on probe
  • Sensor purge provides superior chemical resistance
  • Plug & play compatible with Indigo™ series of transmitters
  • Modbus RTU over RS-485
  • Traceable calibration certificate: 6 points for humidity, 1 point for temperature

Key benefits

Proven Vaisala HUMICAP performance

Vaisala is the original innovator of the thin-film capacitive humidity measurement technology, which has now become the industry standard in humidity measurement.

No condensation at extreme humidity

Probe heating functionality heats up the whole probe head. When probe temperature is heated above dew point temperature, condensation on the probe can be avoided.

Flexible connectivity

The probe is plug and play compatible with Vaisala Indigo series transmitters, can be used as a standalone digital Modbus RTU transmitter, or connected to Vaisala Insight™ PC Software.

Indigo Selector

Discover your ideal Indigo compatible probe and transmitter combinations with the Indigo Selector tool.

Indigo Selector

Product Resources


Indigo500 series dual-probe support

Learn about the benefits of using two probes measuring either the same parameter or two different ones.

Read more


Real-life use cases of humidity calculations

In this webinar, we will cover real-life use cases of humidity calculations and answer the most asked questions, such as how to interpret humidity calculator values? What to take into account when adjusting process? 

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Customer case

Malting process improved using Indigo500 with HMP7 and TMP1 probes

As one of the world’s leading suppliers of high quality malt products, Viking Malt has investigated the advantages of continuous humidity monitoring inside the malting process at its facility using Vaisala’s Indigo520 and  HMP7 and TMP1 probes.

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Customer case

Optimized drying process helps Isolava cut energy consumption and improve end-product quality

Isolava began a project to optimize the drying process, led by Project Engineer Peter Vaneyghen. The first step was to install humidity sensors in the dryer in order to get a better understanding of the dynamics of the drying process. The consumption of natural gas alone has decreased by some 20% and the annual savings across all ten dryers add up to hundreds of thousands of euros.

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What is a smart measurement probe and what makes it special?

Environmental measurement devices are also becoming smart. Unlike in the past when measurement probes could not be used on their own, the new wave of smart measurement probes can operate independently without additional transmitters. 

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Measuring humidity in condensing environments

Taking measurements in environments with high relative humidity (over 90%) is always a challenge because the environment is so close to saturation. 

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Vaisala Indigo500 Condensation prevention & temperature compensation

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Vaisala Indigo Family humidity and temperature probes

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Vaisala humidity calculator

Relative humidity, absolute humidity, wet-bulb temperature, enthalpy, water concentration, and many more. Humidity calculations and conversions made easy.

Humidity Calculator