CO₂ probe (digital) - including temperature and humidity sensor, wired

SKU 0632 1552

Use the probe with the compatible testo multifunction measuring instrument (please order separately) to determine CO2 concentration, air humidity and air temperature. Wet bulb temperature, dew point and absolute humidity are calculated at the same time.

CO2 probe including temperature and humidity sensor – features
Use the probe to check the indoor climate, for example in offices, production areas or storage facilities. To ensure accurate measurement results, air density compensation is carried out via the integrated absolute pressure measurement.
Use the fixed cable on the handle to connect the CO2 probe to the measuring instrument (please order separately).

Particularly useful: store individual readings directly in the measuring instrument by pressing the button on the probe. The clearly structured measurement menu for long-term measurement enables the measuring instrument to be operated intuitively. Reading trends are reliably recorded thanks to the convenient input of measurement time and measuring cycle. You can use these trends to evaluate changes in the indoor air quality.

Space-saving: more applications, less equipment
Endlessly versatile: a universal handle can be connected to all probe heads – so you can master more applications using less equipment and save space.

Order the Bluetooth® handle to make it more convenient to carry out your measurement and guarantee less cable clutter in the case. This transmits the readings to the measuring instrument from a distance of up to 20 metres. If the sensors (CO2, humidity, temperature) need to be replaced in the distant future, you can change the probe head.

Intelligent calibration concept
You will get exceptionally accurate measurement results with the digital probe, because the measuring instrument makes measurement uncertainty a thing of the past. You only need to send the probe head in for calibration – so the measuring instrument remains in continuous use.

Areas of application for the CO2 probe
Use the CO2 probe including temperature and humidity sensor to check the indoor climate (indoor air quality), e.g. in offices, production areas or storage facilities.

The CO2 concentration is a primary indicator of indoor air quality. Poor air quality due to excessive CO2 concentration results in tiredness and lack of concentration, and can even cause illnesses. The CO2 concentration should therefore not normally exceed 1,000 ppm.



Temperature - NTC

Measuring range

0 to +50 °C


±0.5 °C


0.1 °C

Humidity - Capacitive

Measuring range

5 to 95 %RH


±3 %RH (10 to 35 %RH)

±2 %RH (35 to 65 %RH)

±3 %RH (65 to 90 %RH)

±5 %RH (Remaining Range)

±0.06 %RH/K (0 to +50 °C)


0.1 %RH

Please see the additional accuracy information for humidity in the instruction manual.

Absolute Pressure

Measuring range

+700 to +1100 hPa


±3.0 hPa


0.1 hPa

Ambient CO

Measuring range

0 to 10000 ppm


±(50 ppm + 3 % of mv)

(0 to 5000 ppm)

±(100 ppm + 5 % of mv)

(5001 to 10000 ppm)


1 ppm

General technical data

Storage temperature

-20 to +60 °C


200 g


295 x 50 x 40 mm

Operating temperature

-5 to +50 °C

Length probe shaft

130 mm

Cable length

1.4 m

Probe head diameter

30 mm

Product colour



Datasheet : Testo 440