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  4. Climate measuring instruments
  5. BZ26

CO2 air quality monitor BZ26

With the BZ26 CO2 indicator light, you always keep an eye on the air quality - suitable for use as a protective measure against infectious aerosols and for greater overall well-being.

When does the room have to be aired? With the BZ26 you’ll know it!

The air quality has a strong impact on our well-being. The CO2 content in the air is a good indicator for showing at which point a room has to be aired by opening the windows. Timely ventilation is especially important in rooms with a large number of people and is one of the recommended protective measures against airborne infection with diseases. The temperature and humidity level are two further factors with a strong impact on our health. It therefore pays off to keep track of these room air quality criteria.

The BZ26 reliably monitors the key air quality parameters

  • CO2 concentrations (Measuring range: 400 to 5,000 ppm)
  • Indoor room temperature (Measuring range: -9.9 °C to 60 °C or 14.18 °F to 140 °F)
  • Relative humidity (Measuring range: 20 % RH to 95 % RH)

and indicates the measured values in differently coloured areas on its clearly arranged and three-stage dimmable display. With its easily comprehensible smiley symbol, the feel-good indication tells you whether the room climate is ideal, acceptable or in a critical state. Additionally there is a visual and acoustic signal that can alert you if limit values are exceeded.

CO2 traffic light, ensuring a healthy environment for living, studying and working

The BZ26 offers you reliable monitoring of the indoor air quality for improved health protection. Ideal to be used for example in school classrooms, day-care centres, offices, waiting rooms, meeting rooms, seminars and of course at home. Allowing you breathe deeply and freely with a good feeling. The high informational content of the BZ26 is topped off by an indication of the time, date and weekday, and a programmable alarm clock with snooze function.

Airing without wasting energy

Airing for longer periods and more frequently “just in case”? Not a good idea when energy prices are high. Uncontrolled airing can get very expensive by wasting energy. Airing with the BZ26 will be more efficient and convenient. Rooms will only have to be aired specifically and just for as long as it’s really necessary to ensure health protection.

Automatic baseline calibration

The expected CO2 fresh air value is about 400 ppm (0.04 % vol.) nowadays. CO2. The device assumes this value to be the lowest limit value (baseline). Over several days, a special algorithm now permanently checks the lowest CO2 value measured of the sensor over a preconfigured time interval and slowly corrects every long-term drift determined by comparison with the expected fresh air value of 400 ppm (or 0.04 % vol) CO2. In normal indoor applications, the carbon dioxide level constantly decreases almost to outdoor air level during one week. By recording the values over a period of 7 days and then comparing the lowest value to the 400 pm point, the device determines whether or not it needs to adjust the zero point. This takes place fully automatically. The algorithm therefore makes use of the fact that the CO2 content in buildings and rooms regularly stabilises at a minimum for a certain period of time when they are not occupied. In rooms that are continuously occupied or where there is a constantly increased CO2 concentration (e.g. in greenhouses), this principle of automatic balancing therefore does not work.

Comfort chart

The comfort chart indicates the feel-good climate range

As illustrated in this comfort chart (according to Leusden and Freymark), we feel most comfortable at temperatures between 20 and 22 °C and a relative humidity of 40 to 60 %.

Climate conditions beyond these values are perceived as unpleasant by most people. Moreover, too high humidity levels can cause the most varied types of damage. Often, the first visible warning signs are damp articles of clothing, a musty smell and stained walls (mould stains) or sprouting potatoes in basements. For example, did you know that mould can already form at 70 % humidity – and rust at just 60 %? If it is not controlled, the humidity level in a room can fluctuate significantly and rarely reaches the ideal values on its own – and it additionally also depends on the season and climatic conditions outdoors.

With the indoor climate monitoring unit you can easily keep an eye on the temperature and humidity level. 

Increased well-being and health protection by a controlled room climate

Various factors determine whether the air at home, in the living room or children's room, in the classroom, at the workplace or in production environments is good for our health. Room temperature and air humidity have a direct impact on our general well-being. Our body responds if the room climate is too cold or too warm, too dry or too humid. A humidity level that is too high can also favour the formation of mould spores. The carbon dioxide concentration in the air also has a major impact on our performance ability – even if it is within the permissible limit values. A high CO2 concentration can cause fatigue, a lack of concentration and a loss in performance, and children or weakened persons may suffer serious health problems. With the BZ26 you keep track of all important room climate values and you can specifically implement measures to improve the air quality.

CO2 monitoring reduces the risk of a infection

In pandemic times like that of the corona pandemic, the CO2 content in the room air as well as airing in compliance with the principles of infection protection have an important role to play. The concentration of carbon dioxide (CO2) is widely regarded as a good indicator for a high degree of aerosol load in interior spaces. Aerosols were considered as the main carrier of the SARS-CoV-2 virus. Aerosol researchers assume that more than 90 percent of all infections in interior spaces take place by inhaling infectious aerosols previously emitted by sick persons exhaling, talking, coughing or sneezing. 

The CO2 traffic light BZ26 makes high CO2 concentrations and necessary airing visible. Additionally, an individual CO2 limit value alert can be defined, emitting an acoustic and visual alarm signal when limit values are exceeded. 

Less waste of energy by controlled airing

In the cold time of the year, the BZ26 furthermore helps saving valuable heating energy, as controlled airing only takes place for just as long as it’s really necessary and only when the necessity for it is actually indicated by the measured values. In this way, the warmth can be preserved for a longer period of time and the room does not have to be re-heated again and again.

Air quality monitor BZ26 – indispensable for healthy airing and a good room climate

With the BZ26 you can always reliably keep an eye on the interior air temperature. The measuring device can be operated by both mains power (USB cable supplied) and batteries (3 x AAA type alkaline, 1.5 V). A practical foot and an integrated wall holder offers you free choice of where you wish to position the measuring device. In battery operation, the "DOWN" button has to be pressed to determine the CO2 value. With operation of the device via USB connection, the BZ26 measures the CO2 content in the air every 6 seconds fully automatically.

  • Recommended for the hygiene concept of schools, day-care centres, nursing facilities, gyms or restaurants: Real-time measurement of carbon dioxide concentrations in the room air
  • Simultaneous indication of CO2 values, room temperature, humidity level, date, weekday and time
  • Minimum and maximum value function for CO2, air temperature and humidity level
  • Carbon dioxide alarm function with acoustic alarm signal for a freely definable limit value
  • Additional CO2 indicator icon (feel-good indication)
  • Automatic baseline calibration
  • Manual calibration

Scope of delivery

  • 1 x Measuring device BZ26
  • 1 x USB cable
  • 3 x Battery, 1.5 V AAA alkaline
  • 1 x Quick guide

The BZ26 impresses with style and functionality

BZ26 – dimensions
Compact and flat air quality monitor for detecting and visualising the CO2 content in the room air.
BZ26 – functions
All important air quality parameters at a glance. Additional indication of time, date and weekday plus an alarm function.
BZ26 – feel-good climate range - very good
Indication of the CO2 load with a coloured smiley symbol in traffic light colours as feel-good indication.
BZ26 – feel-good climate range - good
Indication of the CO2 load with a coloured smiley symbol in traffic light colours as feel-good indication.
BZ26 – feel-good climate range - poor
Indication of the CO2 load with a coloured smiley symbol in traffic light colours as feel-good indication.
BZ26 – feel-good climate range - very poor
Indication of the CO2 load with a coloured smiley symbol in traffic light colours as feel-good indication.
BZ26 – alarm function
Carbon dioxide alarm function with visual and acoustic warning signal for a freely definable CO2 limit value.
BZ26 – 3 brightness levels
Dimmable colour display with impressive brilliance. Three brightness levels allow for individual adjustment of the lighting to the room/lighting conditions– level 1: 100 % / level 2: 30 % / level 3: 1 %.
BZ26 – power supply
Power supply via the supplied USB cable with mains current or batteries (3 x AAA type alkaline, 1.5 V).
BZ26 – positioning
Thanks to the integrated folding foot and recessed wall holder, the device can be installed on the floor or on the wall.
BZ26 – operation
Rear control panel allowing for user-friendly handling. In battery operation, the "DOWN" button has to be pressed to determine the CO2 value. With operation via the USB cable, the BZ26 automatically measures the CO2 content in the air every 6 seconds.

BZ26 – A practical, universally applicable solution!

BZ26 – workplace
Controlled airing at the workplace, in the co-working space or anywhere where several persons are in one room – without wasting heating energy. Assisted by the BZ26, you only air a space when it is really required and just for as long as necessary.
BZ26 – schools/daycare facilities for children
Proper airing in schools or in day-care centres? No problem at all with the BZ26! The air quality monitor shows you when and for how long you have to air a room so that the air is clean.
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:

  • Simultaneous indication of air quality (CO2 concentration), room temperature, humidity level, time, date and feel-good indication
  • Feel-good indication
  • Individual CO2 alarm limit value definition with visual and acoustic warning signal display
  • Wake-up function with snooze button
  • Additional CO2 indication (feel-good indication) with symbols
  • Absolutely silent (except for the alarm function)
  • Minimum and maximum value function for CO2, air temperature and humidity level
  • Setting option between °C and °F
  • Battery indication
  • LC display with clear and easily legible measured value indication
  • 3 dimmable brightness levels (100 % / 30 % / 1 % brightness)
  • Automatic baseline calibration
  • Manual calibration
  • Compact table or wall-mounted device in modern and stylish design
  • Supplies helpful information on the prevention of mould formation
  • Optimum value-for-money ratio
  • Power supply with mains current (USB cable supplied) and batteries (3 x AAA type alkaline, 1.5 V)


CO2 Air Quality Monitor BZ26 show in Trotec online shop

CO2 Air Quality Monitor BZ26

You save: 31 %

79.95 £ 54.95 £ incl. VAT Show net price (VAT not included)


Technical data

Technical data
General information
  Article number 3.510.205.055
Air temperature [°C]
  Min. measuring range | Air temperature [°C] -9.9
  Max. measuring range | Air temperature [°C] 60
  Resolution [°C] 0.1
  Accuracy <0 °C ±2 °C
  Accuracy 0 °C bis 40 °C ±1 °C
  Accuracy >40 °C ±2 °C
Air temperature [°F]
  Min. measuring range | Air temperature [°F] 14
  Max. measuring range | Air temperature [°F] 140
  Resolution [°F] 0.1
  Accuracy 20 % bis 39 % ±8%
  Accuracy 40 % bis 80 % ±5%
  Accuracy 81 % bis 95 % ±8%
Relative humidity (%)
  Min. measuring range | Relative humidity [%] 20
  Max. measuring range | Relative humidity [%] 95
  Resolution | Relative humidity [%] 1
Carbon dioxide (ppm)
  Carbon dioxide sensor PAS-Sensor (photoakustische Spektroskopie)
  Min. measuring range | Carbon dioxide [ppm] 400
  Max. measuring range | Carbon dioxide [ppm] 5,000
  Accuracy | Carbon dioxide [ppm] 50
  Accuracy | Carbon dioxide [%] 5
  Resolution | Carbon dioxide [ppm] 1
Power supply
  Internal (battery)
  External (USB)
  Internal (battery) 3 x 1,5 V AAA
Ambient conditions
  Operation - min. temperature [°C] -5
  Operation - max. temperature [°C] 50
  Operation approx. - max. relative humidity (non-condensing) [%] 90
  Storage - min. temperature [°C] -5
  Storage - max. temperature [°C] 50
  Storage - max. relative humidity (non-condensing) [%] 90
  Length (packaging excluded) [mm] 89
  Width (packaging excluded) [mm] 125
  Height (packaging excluded) [mm] 22
  (packaging excluded) [kg] 0.165
Standard scope of delivery
Standard scope of delivery
  Measuring device
  Operating manual
  USB cable
Ascertainable measured values and functions
Internal sensors
  Temperature [°C]
  Temperature [°F]
  Relative humidity [%]
Functions and features
  Measurement of air temperature and relative humidity
  CO2 measurement
  Alarm function
  Snooze function
  Switching function for temperature measuring units °C/°F
  Minimum value display
  Maximum value display
  Alarm function
  Battery status indication
  Automatic Baseline Calibration

 standard equipment

 optionally available

 not available



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