With our large range of air velocity probes (please order separately), you can carry out simple and convenient measurements even at locations that are difficult to access in ventilation ducts or at air outlets:
you will even find it easy to carry out measurements in particularly large ducts. This is because the extendable telescope on the hot wire and vane probe (Ø 16 mm) with universal handle can be further extended using the telescope extension – enabling you to attain a total length of 2 metres.
Carry out measurements at air/ceiling outlets effortlessly and without using a ladder. Fit your vane probe (Ø 100 mm) with the telescope with 90° angle and, if necessary, with the telescope extension (both can be ordered separately).
Greater freedom thanks to Bluetooth: the air velocity probes with Bluetooth have no inconvenient cable connection to the measuring instrument, and they transmit readings up to a distance of 20 m. Press the button on the probe to operate the measuring instrument – for example, to start and stop a series of measurements (timed mean calculation).
Attach the testo 440 air velocity and IAQ measuring instrument to metal surfaces (e.g. ducts) easily using the practical magnets.
Benefit from fast calculation of the volume flow: in the “volume flow” measurement menu of the multifunction measuring instrument, configure the dimensions and geometry of the duct cross-section – the measuring instrument shows you the volume flow straight away.

Poor indoor air quality due to excessive concentrations of CO₂ can cause tiredness, lack of concentration and even illness. With its menu for recording readings, the testo 440 air velocity and IAQ measuring instrument is ideal for monitoring the indoor air quality. Enter the measurement time and the measuring cycle – and, for example, track the change in CO₂ concentration or humidity and temperature values over the course of the day. Simply choose between probes with Bluetooth or fixed cable for CO₂, CO or humidity (please order probes separately).

Determine the degree of turbulence and the draught risk in the workplace: draught restricts the comfort level and is the most common cause of complaints about the indoor climate. The turbulence probe (please order separately) measures air velocity and air temperature, and automatically calculates the draught risk and the degree of turbulence in accordance with EN ISO 7730/ASHRAE 55.
For convenient measurements at varying heights, we recommend using our measuring tripod for comfort level measurement (please order separately). This makes it very easy to position turbulence probes in compliance with the standards.

The testo 440 air velocity & IAQ measuring instrument is also ideal for a wide variety of applications in cleanrooms and laboratories in conjunction with the following probes:

• High-precision flow measurement in fume cupboards with the fume cupboard probe
• Thanks to the low start-up speed of 0.1 m/s, the high-precision vane probe (Ø 100 mm) is ideal for laminar flow measurements in cleanrooms. It is available as a variant with Bluetooth or with fixed cable
• To measure the humidity in cleanrooms, we recommend the high-precision humidity/temperature probe (0636 9771 or 0636 9772). With an accuracy of ±(0.6 %RH + 0.7% of m.v.) (0 to 90 %RH), it also meets the requirements for humidity measurements in this particularly sensitive area
• Use the high-precision digital Pt100 temperature probes, for example, for high-precision comparative measurements in calibration laboratories, temperature measurements in chemical laboratories or in the cosmetics industry as well as for determining the temperature distribution in refrigerators and conditioning cabinets