Humidity, Dew Point
and Moisture measurements

Water (H₂O) can present itself in three different forms: solid (ice), liquid (water), and gas (humidity). Humidity is an invisible gas that can be measured and defined with different parameters. Relative humidity indicates the present state relative to maximum humidity in a given temperature. Dew point temperature indicates the temperature to which air needs to be cooled in order to reach condensation. For industrial-scale manufacturing, controlling these parameters is a must for good quality end-products and efficient manufacturing processes.

Get to know Vaisala’s reliable and durable measurement solutions for humidity, dew point, and moisture.

Humidity

Humidity is measured in many air control applications, where the relative humidity is for the most part over 10 %. Relative humidity (RH) is a measure of the water vapor content of air. For more information, read the article what relative humidity is and why it is important.

Find humidity measurement products by typical applications:
test chambers, building automation and HVAC, spray drying, paint booths, biogas production , and bio-decontamination.

Humidity guide for smart industries

White paper: Controlling high-humidity applications with dew point temperature

This white paper is a vital resource for anyone aiming to maintain a controlled environment in a high-humidity application.

Download the White Paper

Dew Point

Dew point measurements are needed when controlling air in dry processes, usually with relative humidity below 10 %. For more information about dew point, read the article "What is dew point and how to measure it?". Find dew point measurement products by typical application: compressed air drying, fluid bed drying, 3D printing, lithium-ion battery manufacturing, and semiconductor manufacturing.

Choose the right instrument for humidity and dew point

Moisture

Avoiding moisture in concrete or structures requires high quality measurement. Moisture measurements are essential also when there is a need to protect engines or to ensure high-quality oil with moisture in oil measurements

Moisture in Oil (MiO) measurement

Dew point temperature or frost point temperature?

Select the correct parameter output to low humidity applications

Sometimes, the terms are mixed in the industrial language, and dew point temperature might actually refer to frost point temperature.

Read Vaisala's recommendations here (PDF)

Humidity control in hazardous locations

Humidity control is critical in many spaces where flammable or explosive materials such as fuels, chemicals, explosives are being stored. These spaces are designated as hazardous due to potentially explosive atmospheres. They require specially designed and approved instruments for safe operation.

Vaisala's intrinsically safe humidity instrument for hazardous locations is the HMT370EX Humidity and Temperature Transmitter.

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High-quality measurement benefits

Energy-savings

Especially in drying applications, accurate humidity measurement can bring significant savings in both energy and costs. By knowing the humidity level you can, for example, avoid over-drying and heating the air too much.

End-product quality

Exact humidity data helps you optimize your production process and facilities, as well as make sure that the humidity level in your end-products is just right. Depending on the product, it can mean for example longer shelf life or improved stability.

Safety & well-being

Humidity control in facilities and moisture control in structures improve both safety and well-being when the air is optimized for breathing and the formation of mold is avoided. Controlling process humidity is also crucial for safety and well-being.

Vaisala humidity calculator

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

Humidity Calculator

Try our dew point instrument finder

Trusted HUMICAP® and DRYCAP® technologies

We have been the industry leader in humidity measurements for over 40 years. Our solutions are suitable also for very demanding measurement conditions. Vaisala’s HUMICAP® and DRYCAP® technologies have been trusted for decades due to their accuracy and stability.

Humidity and Multigas Measurements with CARBOCAP® and PEROXCAP®

With our continuous research and development efforts, we have been able to combine humidity measurement possibilities also with other parameters and technologies. We developed the CARBOCAP® technology originally for measuring CO₂, but the technology is well suited also for optical humidity and methane measurements in biogas applications. Vaisala’s PEROXCAP® technology was developed for measuring humidity, vaporized hydrogen peroxide and temperature for easy validation of hydrogen peroxide bio-decontamination of isolators and facilities.

HUMICAP Humidity and Temperature Probe HMP155

Vaisala’s HUMICAP® Humidity and Temperature Probe HMP155 delivers accuracy and reliability under even the most challenging conditions including tropical, coastal, and marine environments.

The HMP155 is engineered to deliver precise data in high humidity climates where moisture is near saturation, in environments with changing temperatures, and in harsh environments where measurements may be corrupted by chemicals, fog, mist, rain, and heavy dew.

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Humidity measurement product highlights for HVAC

Indigo520 Transmitter wall installation in an industrial setting

Indigo Family - the modular platform

The Vaisala Indigo family is a customizable instrument platform designed to improve process measurements. The Indigo family's key feature is modularity.

Humidity and Temperature Transmitters HMT120/130

The Vaisala HUMICAP® HMT120 and HMT130 transmitters are suitable for cleanrooms, museums, laboratories and data centers.

Wall-mounted Vaisala GMW90 Series Carbon Dioxide, Temperature and Humidity Transmitters are especially suited for green building projects and DCV.

CO2, Temperature and Humidity Transmitter Series GMW90

The wall-mounted Vaisala GMW90 Series CARBOCAP® Carbon Dioxide, Temperature and Humidity Transmitters are especially suited for green building projects and demand controlled ventilation.

Humidity and Temperature Transmitter Series HMW90

Typical applications are include museums and archives, production and warehouse facilities, data centers, laboratories, and testing environments.

Duct Humidity and Temperature Transmitter HMD60

The sturdy and reliable duct mounted Vaisala HUMICAP® Humidity Transmitter Series HMD60 is designed for monitoring relative humidity in demanding HVAC and light industrial applications

Dew point and relative humidity product highlights for industrial drying

Probe head and probe body of the DMP6 for very high temperatures

Dew Point Probe DMP6

Vaisala DRYCAP® Dew Point and Temperature Probe DMP6 is designed for in-line humidity measurement in industrial drying applications with very high temperatures and a wide dew point range.

Dew Point and Temperature Probe DMP7

Vaisala DRYCAP® Dew Point and Temperature Probe DMP7 is made for tight spaces and low-humidity applications.

Dew Point and Temperature Probe DMP8

Vaisala DRYCAP® Dew Point and Temperature Probe DMP8 is designed for industrial low-humidity applications with pressure up to 40 bars.

DMT152 Dewpoint Transmitter for Low Dew Point Measurement in OEM Applications

Dew Point Transmitter DMT152

The Vaisala DRYCAP® Dewpoint Transmitter DMT152 is designed for measuring low dew point in OEM applications, even down to -80°C.

The Vaisala DRYCAP® Dewpoint Transmitter DMT143 is a miniature dew point measurement instrument

Miniature Dew Point Transmitters DMT143 & DMT143L (Long)

Miniature size dew point transmitters DMT143 and DMT143L are ideal choices when you want to measure dew point accurately in small compressed air dryers, plastic dryers, additive manufacturing and other OEM applications.

Humidity and Temperature Probe HMP3

Vaisala HUMICAP® Humidity and Temperature Probe HMP3 is a general-purpose probe designed for processes with moderate humidity and temperature levels.

Relative Humidity and Temperature Probe HMP7

Vaisala HUMICAP® Humidity and Temperature Probe HMP7 is designed for applications which involve constant high humidity or rapid changes in humidity

Relative Humidity and Temperature Probe HMP8

Vaisala HUMICAP® Humidity and Temperature Probe HMP8 is designed for pressurized applications in compressed air systems, refrigerant dryers, and other pressurized industrial applications where easy insertion and removal of the probe and adjustable installation depth into the pipeline are needed.

Expert articles

Dew point temperature – What does it mean and how can it be calculated?

Following on from our previous post on relative humidity (RH), let’s look at the second most commonly used humidity parameter – dew point temperature.

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How to choose the right instrument for measuring humidity and dew point

Humidity measurement and control is called for in a wide variety of industrial applications. Each application has a different set of requirements for humidity instruments, such as required measurement range.

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How to choose the right humidity instrument for your high-humidity application

Tips on how to select the right humidity instrument for your high-humidity application

High-humidity environments are tough for humidity measurement. Saturation in the environment causes condensation to form on all surfaces including measurement sensors, which can be fatal for some technologies.

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The importance of humidity sensors

Humidity sensors are among the most commonly used instruments in environmental monitoring applications. Why? Because they are one of the most important measurements to get right when looking to create comfortable, safe, and energy efficient environments.

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Wet-bulb temperature – from traditional psychrometers to a modern humidity control variable

In the past, a psychrometer was a convenient device to measure humidity in an environment. In the modern world, the requirements for measurement accuracy and overall usability have changed.

Learn more