Hygrometers for measuring humidity

Humidity is an indication of how much water vapour is in the air around us. It has a considerable influence on our well-being and is one of the most frequently determined measurement parameters. Particularly in enclosed spaces, it is important to determine not only the temperature but also the humidity using a thermohygrometer.

What Testo thermohygrometers offer you

  • Extremely long-term stable humidity sensors
  • Highly sensitive probes for a wide range of applications
  • Robust and compact measuring instruments and thermohygrometers


Humidity meter
Also calculates dewpoint and wet bulb temperature.

Infrared thermometer with humidity measurement

Air humidity meters
With 4-point laser and 50:1 lens for remote measurement of air humidity.

Meters with connectable probes

Humidity measurement
Measure air humidity and other VAC parameters with just one instrument.

Humidity meters with-smartphone-operation

Air humidity meter with connectable probes
Fast, digital, highly efficient and with an App.

Humidity probes

Measure air humidity
Wide variety of external probes – for every application involving humidity measurement.

Excessively high humidity

If the humidity in the air of a room is too high (higher than 60%), this means that the air can no longer absorb water. The consequence: Condensation is generated. This precipitates on the window or on walls – and there is a risk of mould. Cold bridges in particular pose a risk here, and must be monitored.

Excessively low humidity

Too little moisture in the air dries out the respiratory tract and makes it susceptible to related diseases. Frequent ventilation and, if necessary, a humidifier can help here. Incidentally, the ideal humidity in rooms is 50%.

Applications for thermohygrometers

Measure humidity with a hygrometer – but make sure you do it right

To use a thermohygrometer to find out what the humidity is really like, there are a few tips to bear in mind. This will ensure that your hygrometers provide you with accurate readings, from which you can then derive appropriate optimization measures. For a start, it’s good to know that the ideal humidity of a room is approximately 50%. At a humidity of 60% there is a risk of mould. If the value is below 50%, the risk of respiratory diseases increases as the human mucous membranes dry out.

How to contact us.

Do you have any questions? We're happy to help you.

Regional Office (Singapore, Malaysia, Indonesia)


How to make best use of hygrometers

When using a thermohygrometer to measure humidity, there are a few pitfalls that you should avoid in order to achieve the best possible result with your measuring instrument.

  • Always measure in the centre of the room and at chest height.
  • Keep the measuring instrument away from your body with your arm outstretched.
  • When using a humidity sensor, gently wave it twice per second, in small movements.
  • Make sure that your breathing air does not falsify the result.

Tracking mould with hygrometers

One particularly unpleasant consequence of high humidity is the formation of mould. Mould usually develops when the moisture content of the air is above 60% for an extended period of time. Particularly at risk are exterior walls, cold bridges and poorly ventilated areas behind sofas, shelves or cupboards.

Tips for preventing indoor mould:

  • Make sure that there is always enough space between furniture and walls for air to circulate.
  • Ventilate regularly.
  • Monitor humidity and temperature using appropriate measuring equipment, such as a thermohygrometer.
mold measurement

testo 400 universal IAQ instrument

The testo 400 in the webshop


Consistently smart humidity and IAQ measurements.

Find out all about the new testo 400 universal IAQ instrument – your new companion for all your IAQ and humidity measurements.

  • Smarter: The intuitive Smart-Touch display makes it as easy to use as your smartphone.
  • Faster: You can create and send all measurements directly on site.
  • Better: Built-in measuring assistant for guided step-by-step measurements
  • More universal: Comprehensive selection of probes for all IAQ parameters. Lots of probes are also available as wireless Bluetooth versions. This gives you more scope for measurement.

Other measuring instruments for moisture, temperature and air humidity

To accurately record the IAQ indoors, you need to record other measurement parameters in addition to humidity. These include temperature, humidity and material moisture. With measuring technology from Testo – such as hygrometers – you are ideally equipped for these measuring tasks. Benefit not only from Testo’s more than 60 years of experience, but also from high-quality precision measuring instruments, a comprehensive selection of probes and our tried-and-tested customer service, which always has your back when you need it.

Testo thermohygrometers

Record and monitor humidity

For certain applications, you need not only to measure air humidity selectively, but also to measure and document it over a period of time. This can be particularly useful in storage rooms for moisture-sensitive foods. The suitable measuring instrument for this task is a humidity data logger. Compact, precise and reliable, it measures humidity at freely selectable intervals and records the measured values for later analysis.

Multifunctional humidity measurement

If you want to measure not only air humidity but also material moisture quickly and reliably, you need a moisture meter. Thanks to the comprehensive selection of humidity sensors, you will always have the right measuring technology to hand.

Material moisture measurement

In the building trade or in heating engineering, material moisture is an important measurement parameter. For example, this can be determined for concrete, masonry and screed or firewood. At Testo you will also find your ideal material moisture measuring instrument.

Air humidity measurement

Its name says it all – an air humidity meter (also called a thermohygrometer) measures the moisture content in the air. Indispensable for indoor areas.