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BZ20M thermohygrometer
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BZ20M thermohygrometer

Perfect climate control in cross-needle design

High-quality mechanical measurement technology "made in Germany"

You'll find it hard to find a quicker and simpler way to control indoor climate values. And hardly a prettier solution, either – it is a treat for the eyes... The thermohygrometer BZ20M is surrounded by a high-end stainless steel housing. With a diameter of 130 mm and the special scale design it can be easily read even at a larger distance.

Thanks to the ingenious needle arrangement you can tell by one look when the climate values are within the optimum range. For as long as the pointers for room temperature and humidity cross above the field marked in grey, your room climate is just perfect.

The measuring device BZ20M is the first choice whenever an equally precise and quick check of an healthy indoor climate is required; such examples include office spaces, training and conference rooms or, more privately, living and bedrooms.

The humidity measuring range of the hygrometer covers all values between 20 and 100 % RH with a measurement accuracy of ± 3 % RH.

Control and optimization of heating and ventilation behavior

The high quality mechanical measurement technology "made in Germany" speaks for itself, but it also says something for the thermohygrometer BZ20M: The mechanism is employed to measure the change in length of a specially pre-treated synthetic fibre that expands in humid conditions and contracts when it is dry.

The length variation is converted into a rotary motion using levers and axes and visualized by means of a needle. The display of the maintenance-free hygrometer can easily be calibrated and amended by way of a zero correction.

Another convincing argument for the reliability of the measuring device with cross-needle design is its bi-metal thermometer. The figures clearly speak in favour of the BZ20M as well: In the temperature measuring range between -10 and 40 °C it captures values with a measurement accuracy of merely ± 2 °C. 

BZ20M – Special equipment features

BZ20M - Dimensions
The true size of the compact BZ20M becomes apparent through its advantageous dimensions. With a convenient diameter of 13 cm, the dial is easy to read even from a distance.
BZ20M - relative humidity display
On the left-hand scale, the relative humidity is displayed in a measuring range from 20 to 100 %. Unwanted deviations from the desired target range become visible at one glance.
BZ20M - Temperature display
The right scale shows the room temperature. In the temperature measurement range, it records values between -10 to 40 °C with a temperature measurement accuracy of only ± 2 °C.
BZ20M - Side view
Despite having a depth of only 2.8 cm, the elegantly flat stainless steel housing simply stands out.

Application examples from practice:

BZ20M - Library application
There is no more stylish way to control room humidity in the library. The BZ20M blends in perfectly with the ambience to keep an eye on humidity and prevent moisture-related mold growth. Permanently regulated humidity protects against moisture damage and helps preserve the value of priceless classic books.
BZ20M - Application Practice
With the BZ20M thermohygrometer, you can keep an eye on the important parameters of a healthy working climate in an attractive way, so that you can take countermeasures with controlled air humidification or dehumidification if necessary. Optimally regulated humidity increases well-being in the workplace for employees and patients.
BZ20M - Hotel application
Excessive humidity is a common cause of mold growth. Prevent this health risk. The BZ20M thermohygrometer fits harmoniously into modern hotel rooms, bedrooms and living rooms. Excessive humidity values that require manual window ventilation or permanent dehumidification are visible at a glance.
Technical data by comparison

All climate measuring devices in direct comparison:

To find the climate measuring device which exactly meets your requirements, please consult the concise overview of all climate measuring devices from Trotec, which we're providing to you here so that you can compare them directly to each other.

Models which you do not wish to include in your comparison can be easily dismissed with only one click.

Technical data by comparison

A few practical benefits:

  • High-quality mechanical measurement technology "made in Germany"
  • Special cross-needle scale design
  • Simple readability allowing a quick interpretation of the measured values
  • Incl. calibration option


BZ20M Thermohygrometer show in Trotec online shop

Technical data

Technical data
General information
  Article number 3.510.205.013
Air temperature [°C]
  Min. measuring range | Air temperature [°C] -10
  Max. measuring range | Air temperature [°C] 40
  Resolution [°C] 1
  Accuracy ± | Air temperature [°C] 2
  Accuracy [°C] 2
Relative humidity (%)
  Min. measuring range | Relative humidity [%] 20
  Max. measuring range | Relative humidity [%] 100
  Resolution | Relative humidity [%] 2
  Accuracy ± [% r.F.] 3
  Accuracy -10 °C - 40 °C - 20 % - 100 % [%] 3
Housing design
  Stainless steel
Ambient conditions
  Operation - min. temperature [°C] -20
  Operation - max. temperature [°C] 50
  Operation approx. - max. relative humidity (non-condensing) [%] 100
  Storage - min. temperature [°C] -20
  Storage - max. temperature [°C] 50
  Storage - max. relative humidity (non-condensing) [%] 100
  Length (packaging excluded) [mm] 130
  Height (packaging excluded) [mm] 28
  (packaging excluded) [kg] 0.185
Standard scope of delivery
Standard scope of delivery
  Operating manual
Ascertainable measured values and functions
Functions and features
  Measurement of air temperature and relative humidity

 standard equipment

 optionally available

 not available

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