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BC21WP thermohygrometer controlled via smartphone
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BC21WP thermohygrometer

Versatile climate measuring device as appSensor controlled via smartphone

The BC21WP allows you to record all important climate parameters
The BC21WP permits the ideal room climate control
With the BC21WP you can control all values for an ultimate storage climate

The appSensor BC21WP is a thermohygrometer permitting measurements of air temperature and relative humidity level when used in combination with the MultiMeasure Mobile app.

The measuring device BC21WP is immediately ready for use, it can be connected to the app without the slightest effort and then displays all the measured values on the mobile terminal device. High-quality sensor technology and numerous measuring functions make the BC21WP the ideal climate measuring device for workshop, hobby and household applications.

Risk of mould growth or rust? Owing to the clever combination of the appSensor and the appertaining, free MultiMeasure Mobile app users benefit from numerous practical advantages in terms of flexibility, analysis functions, data control and documentation.

This way, other important physical climate parameters such as dew point temperature, critical dew point, absolute or specific humidity can be calculated and displayed additionally based on the data determined by the measuring device and transferred to the app. Normally, only substantially more expensive measuring devices can achieve that.

Compare the determined data directly on your mobile terminal device or use the measured values for differentiated on-site analyses.

Due to the real-time determination of all relevant climate parameters, all issues evolving around the building climate control can quickly and easily be investigated using the BC21WP. Further useful features such as the logging function, chart representation of the measurement data or their export to a secondary analysis software as well as the report generation function permit the BC21WP's universal application, i.a. for the planning, measuring and performance control of air-conditioning and ventilation systems.

What is an appSensor?

Trotec appSensor

Trotec appSensors are compact precision measuring devices with high-quality sensors. Designed in a way to save space and energy, they have neither display unit nor evaluation electronics – data analysis and operation are realized almost entirely by means of the connected smartphone. Combined with the free app MultiMeasure Mobile this measuring device concept offers many compelling advantages.

All of Trotec's appSensors offer the following advantages:

  • Professional sensors for precise measuring results
  • Foolproof connection of the app via Bluetooth with visual connection confirmation by means of an LED at the device
  • Wireless control of the measuring devices and display of data via app
  • Simple measured value detection even at remote locations since the values do not have to be read directly from the measuring device
  • Additional determination and indication of minimum, maximum and average values
  • Hold, logging and alarm functions
  • Wrist strap for safe handling included in the scope of delivery
  • Practice-optimized German industrial design – protected design patent
Trotec appSensors

Why use appSensors? Aren't there a lot of measuring apps already?

Of course there are numerous apps using the electronic components integrated in smartphones, e.g. microphone, gyroscope or camera, for measurements and derived calculations. But these components haven't been designed for precise metrological inspections, instead mainly for an optimized application on a mobile device.

Hence, the obtained results are not in the least comparable with the results achieved by sensors specifically designed for measuring applications. Besides, your smartphone may not be equipped with the suitable electronic component for every measurement task, e.g. for contact moisture measurements or non-contact temperature measurements.

Trotec appSensors on the other hand house professional sensors for precise measuring results –which is just what they were made for. So, be smart and use the clever combination of appSensor and MultiMeasure Mobile – our free app available for both iOS and Android – to carry out professional measurements.

Using MultiMeasure Mobile you can record long-term measurements, save measurement series in form of a chart or export them for a secondary analysis software.
Versatile climate measuring device as appSensor controlled via smartphone
All values measured by the BC21WP can be read clearly when displayed by the MultiMeasure Mobile app.
Numeric display of measured values
By tapping on the screen you can switch between graphic and numeric display.
Chart representation of measured values
The numerous measuring functions of the MultiMeasure Mobile app make the BC21WP an ideal climate measuring device for manifold applications.
Numerous measuring functions for climate control

MultiMeasure Mobile – all of the app's advantages at one glance

MultiMeasure Mobile app

To control this appSensor via smartphone, you first have to download MultiMeasure Mobile – a free app for the operation, evaluation and measured value indication of all the appSensors connected to your mobile device.

MultiMeasure Mobile has numerous advantages in store for you:

  • Automatic identification of appSensors
  • Simultaneous operation of several appSensors
  • Quick and intuitive navigation
  • Numerical measured value indication or else in form of a chart / matrix
  • Integrated report function for the documentation directly on site
  • PDA function for the organization of measurement data and documents
  • Customer management already integrated
  • Manifold analysis options directly in the app
  • Storage of measured values linked to photos
  • Matrix measurements, also linked to photos
  • Complete data synchronization with MultiMeasure Professional via cloud

MultiMeasure Mobile turns your mobile terminal device into a multifunctional measurement data management tool.

All appSensors are automatically identified by the app and can be connected to and read by MultiMeasure Mobile using Bluetooth. The operation is as simple and intuitive as the installation: Simply download MultiMeasure Mobile for free onto your mobile device – click here to go to the iOS or Android download page.

Direct link to MultiMeasure Mobile in the app store:

MultiMeasure Mobile for Android
MultiMeasure Mobile for iOS

BC21WP thermohygrometer as appSensor controlled via smartphone

BC21WP – A few practical benefits:

  • Measurement of diverse climate data with only one device: relative humidity, air temperature, dew point and wet-bulb temperature
  • High-quality sensor technology and numerous measuring functions
  • Intelligent combination of appSensor and MultiMeasure Mobile app
  • Automatic switch-off
Dew point determination and lots more
Combined pyrometer BP21WP as dew point scanner

Our recommendation: using appSensors cleverly combined. If you simultaneously connect the BC21WP and the pyrometer BP21WP to the MultiMeasure Mobile app, you can adopt the dew point determined with the BC21WP as alarm threshold for the pyrometer BP21WP so as to obtain the functionality of a dew point scanner. An acoustic alarm signal generated by the app will be emitted by the terminal device when the measured temperature values reach or fall below the dew point.

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


BC21WP -appSensoren - Thermohygrometer mit Smartphone-Bedienung show in Trotec online shop

BC21WP -appSensoren - Thermohygrometer mit Smartphone-Bedienung

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39.99 € 29.99 € incl. VAT Show net price (VAT not included)


Technical data

Technical data
General information
  Article number 3.510.206.006
Air temperature [°C]
  Min. measuring range | Air temperature [°C] -20
  Max. measuring range | Air temperature [°C] 60
  Resolution [°C] 0.1
  Accuracy ± | Air temperature [°C] 0.5
  Accuracy ±0.8 °C (at -20 °C to 0 °C)
±0.5 °C (at 0 °C to 60 °C)
Air temperature [°F]
  Min. measuring range | Air temperature [°F] -4
  Max. measuring range | Air temperature [°F] 140
  Resolution [°F] 0.1
  Accuracy ± | Air temperature [°F] 0.5
Relative humidity (%)
  Min. measuring range | Relative humidity [%] 0
  Max. measuring range | Relative humidity [%] 100
  Min. measuring range | Specified | Relative humidity [%] 5
  Max. measuring range | Specified | Relative humidity [%] 95
  Resolution | Relative humidity [%] 0.1
  4.0 (BLE)
  Max. transmission range 10 m in open terrain
Power supply
  3 x 1.5V, AAA
Ambient conditions
  Operation - min. temperature [°C] -20
  Operation - max. temperature [°C] 60
  Operation approx. - max. relative humidity (non-condensing) [%] 80
  Storage - min. temperature [°C] -20
  Storage - max. temperature [°C] 60
  Storage - max. relative humidity (non-condensing) [%] 90
  Operation – min. relative humidity [% r.F.] 10
  Operation - max. relative humidity [% r.F.] 90
  Relative humidity during storage [%] <� 80% RH
  Length (packaging excluded) [mm] 22
  Width (packaging excluded) [mm] 32
  Height (packaging excluded) [mm] 226
Standard scope of delivery
Standard scope of delivery
  Measuring device
  Wrist strap
  Operating manual
Ascertainable measured values and functions
Internal sensors
  Temperature [°C]
  Temperature [°F]
  Relative humidity [%]
Functions and features
  Battery status indication
  Minimum value display
  Maximum value display
  Average value display
  Measured value hold function
  Automatic switch-off
  Indication of dew point, critical dew point, absolute humidity [g/m³], specific humidity [g/kg]
  Alarm function
  Long-term measurement function
  Representation of measurement data as chart or table
  Data export
  Report generation function

 standard equipment

 optionally available

 not available



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