testo 405 - Pocket sized thermal anemometer

Special Price 0.00


Use the testo 405 thermal anemometer to measure air velocity, volumetric flow and air temperature. It is suitable for carrying out quick check measurements in ventilation ducts and for measuring the air velocity in rooms for indoor air quality, e.g. at draughty windows.

  • Measurement of air velocity, volumetric flow and air temperature

  • For measurements in ventilation ducts and in rooms

  • Particularly precise in the range between 0 and 2 m/s

  • Telescope extendible to 300 mm


Product Description

If, in your capacity as an HVAC engineer, you carry out fast check measurements in ventilation ducts or in rooms, then testo 405 thermal anemometer is a must-have. The thermal anemometer features a permanently mounted telescope and enables you to measure air flow, volumetric flow and air temperature. The measuring range for flow is between 0 to 10 m/s, volumetric flows are calculated up to 99,990 m3/h.

The extendible telescope (up to 300 mm) makes the thermal anemometer particularly suitable for flow measurements in ventilation ducts. The illuminated display can be swivelled into various positions, ensuring that the readings can be read off comfortably. The duct bracket (included in the delivery) offers key practical advantages. You can use this to optimally position the telescope in the ventilation duct and obtain precise measurement results.

Since the thermal anemometer testo 405 measures particularly accurately in the range between 0 and 2 m/s, you can also use it to measure the air velocity in rooms for checking indoor air quality. Low air velocities, at draughty windows for example, are quickly located and accurately measured using the thermal anemometer.

Integrated sensor protection: when you are not using the testo 405 thermal anemometer, the rotating protective cap protects the flow sensor from mechanical stress.

Delivery Scope

testo 405 thermal anemometer with permanently mounted telescope, including duct bracket, attachment clip and batteries.

General Technical Data
Weight 115 g (with batteries, without packaging)
490 x 37 x 36 mm
Operating temperature 0 to +50 °C
Battery type
3 AAA micro batteries
Battery life Approx. 20 h
Display type LCD
Length probe shaft 300 mm
Diameter probe shaft 16 mm
Diameter probe shaft tip 12 mm
Storage temperature  -20 to +70 °C


Temperature - NTC

Measuring range
 -20 to +50 °C
Accuracy ±0.5 °C
Resolution 0.1 °C


Velocity -Thermal anemometer

Measuring range
0 to 5 m/s (-20 to 0 °C)
0 to 10 m/s (0 to +50 °C)
0 to 99990 m³/h
Accuracy ±(0.1 m/s + 5 % of mv) (0 to 2 m/s)
±(0.3 m/s + 5 % of mv) (Remaining Range)
Resolution 0.01 m/s

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