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Testo 440 - CO2 kit

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The Testo 440 CO2 kit is a practical measurement tool for determining carbon dioxide concentrations, humidity and air temperature and is the ideal device for assessing the indoor air quality in offices, schools, production areas or storage facilities such as warehouses.

The 440 handset is a multifunction measuring instrument which can be used with a number of different optional indoor air quality probes, and the wireless CO2 Bluetooth probe can be used to accurately measure carbon dioxide over the range of 0 to 10,000 ppm as well as temperature & humidity over the range of -10 to +50 °C / 5 to 95 %rh, the handset calculates dew point, wet bulb temperature and absolute humidity.

Product Features

  • Range of accessories
  • Calibration options
  • Document downloads
  • Instrument video
  • Instrument FAQs

Instrument product options

1. Select a model (1 available)

Model subtotal: £619.00
Total (excl VAT): £619.00
Continue to select accessories

2. Select accessories (44 available)

3. Select a calibration (2 available)



  • A compact hand-held measuring instrument with intuitive measurement menus and a wide selection of air velocity and IAQ probes (optional accesories)
  • Clearly structured measurement menus.
  • Easy storage and evaluation of measurement data. Measurement data memory for up to 7500 measurement protocols, which can be read via a USB port and further processed as a CSV file on the computer (e.g. with Excel)
  • Practical magnets for easy attachment of the measuring instrument to metal surfaces (e.g. ducts)
  • Automatic detection of probes, e.g. Bluetooth CO2, temperature and humidity measuring probe
  • Large, backlit colour display

Scope of standard supply

Testo 440 air velocity and IAQ measuring instrument, 3 x AA batteries, USB cable and manufacturers calibration protocol
CO2 probe* with Bluetooth, including temperature and humidity sensor (consisting of CO2 probe head and Bluetooth handle); 4 x AA batteries, table stand and calibration protocol (0632 1551)
Basic case for testo 440 and CO2 probe


Probe part No.      0632 1551

CO2 range     0 to 10,000 ppm

CO2 accuracy      ± (50 ppm + 3 % of mv) : 0 to 5000 ppm, ± (100 ppm + 5 % of mv) : 5001 to 10000 ppm

CO2 resolution      1 ppm

Humidity sensor type      Capacitive

Humidity measuring range     5 to 95 % rh

Humidity accuracy     ± 3 % rh (10 to 35 % rh),  ± 2 % rh (35 to 65 % rh), ± 3 % rh (65 to 90 % rh), ± 5 % rh (remaining range)

Humidity resolution     0.1 % rh

Temperature sensor type      NTC

Temperature measuring range     - 10 to + 50 °C

Temperature accuracy     ± 0.5 °C

Temperature resolution     0.1 °C



Testo 440 product range BSRIA data sheet

  • Technical Document
  • PDF file
  • 4 MB

Testo 440 user manual

  • Technical Document
  • PDF file
  • 3 MB

Testo air velocity and IAQ Bluetooth probe user manual

  • Technical Document
  • PDF file
  • 897 KB

Testo air velocity and IAQ probe user manual

  • Technical Document
  • PDF file
  • 356 KB

Demonstration videos

Testo 440 product range overview
Testo 440 product overview in IAQ applications



When using a wireless Bluetooth probe how far from away from the handset will the probe register a signal ?


Typically the probe will transmit distances up to 5 m (line of sight).


Can you connect two wireless Bluetooth probes to a 440 handset ?


Unfortunately no.  The handset is designed to work with a single wireless Bluetooth probe, a single wired probe and an additional Type K mini plug style thermocouple can additionally be fitted as well.

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