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Air velocity & IAQ measuring instruments

The air meter is a valuable aid when it comes to both setting air conditioning and ventilation systems and assessing indoor air quality.

A multifunction measuring instrument enables you to determine important climate parameters, such as CO2, air humidity, air temperature and absolute pressure, reliably and precisely.

A measuring instrument of this kind goes far beyond a classic hygrometer which is purely for the determination of humidity. The possibility of connecting a variety of optional probes enables different climate factors to be determined.

A multifunctional air meter has the following advantages:

  • Optimum setting of air conditioning and ventilation systems

  • Assessment of indoor air quality or comfort level measurements

  • A wide variety of combination possibilities with a variety of probes for optional measurements

  • easy handling

  • Mobile design

Multifunctional measuring instruments: Online product advisor

to the consultant

Multifunctional climate measuring devices

Instruments and kits

The air meters in comparison


Product details

IAQ instrument testo 400

  • Perfect for standard-compliant measurements

  • Guided programs for HVAC grid measurements and comfort levels (PMV/PPD)

  • Highly accurate, individually calibratable probes

  • Probes can simply be replaced without restarting the instrument

  • Full documentation that can be completed right on site

Multifunctional testo 440

  • Perfect for fast and intuitive measurements

  • Clearly structured measurement menus for all VAC applications

  • Wireless Bluetooth® probes for greater measuring convenience and less cable mess in the measurement case

  • Highly accurate, individually calibratable probes

  • Internal memory with 7,500 measurement values and USB interface for protocol export

Practical guide

Air flow measurements in ducts according to DIN EN 12599

Download the exclusive practical guide for free now.

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Significance of air velocity

Measurement of the right air velocity

The right measurement location

The measurement method

Analysis of the measurement values

The measurement report

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One for all: Why you can save in the long term with a multifunction instrument

Have you ever thought about it?

Multifunction measuring instruments have many advantages which make your job easier:

  • You have one tool to manage, and are equipped for all air velocity & IAQ measurement tasks.

  • You select the probes you need – and you can add more as often as you like.

  • You invest only once – and benefit in the long term from robust, intelligently designed technology.

Sound interesting? Then our multifunction measuring instruments are just right for you.

Climate measurement for the precise determination of air humidity

Ideal for determining a variety of climate parameters

The multifunction air meter can be a great help to you, when you not only need to carry out a humidity measurement but also to determine several different climate parameters. Depending on the instrument, air meters can be upgraded using various probes to enable values such as absolute pressure, air temperature or CO₂ content in the air to be determined. The functions therefore go far beyond those of a pure humidity meter and enable the determination of various climate parameters with just one instrument. The multifunction air meter thus supports you in determining a variety of factors for indoor air quality assessment and comfort level measurements. Furthermore, it provides you with an important aid in terms of the precise setting of ventilation and air conditioning systems.

Modern multifunction measuring instruments offer the following advantages:

  • Easy readout of precise measuring values on the display

  • Determination of many different climate parameters with just one instrument

  • Optional probes enable the measuring instrument to be upgraded for individual needs

Optimum air quality – perfectly under control thanks to cutting-edge measuring instruments

A variety of factors play an important role in terms of optimum air quality. An indoor air meter enables you to determine the temperature, air humidity or also the CO₂ content in a room. The measurement of these parameters provides a good basis for assessing indoor air quality.

In addition, the appropriate probes enable you to determine even more measuring values in terms of assessing air quality. An extremely precise indication of mould is for instance enabled in this way. A pure air humidity meter alone is therefore not sufficient when it comes to meaningful and all-encompassing air quality assessment.

Testo's measuring instruments enable you to enjoy measurement options for your individual needs through retrofitting with optional probes.

Set ventilation and air conditioning systems correctly with the air meter

Does your task involve setting ventilation and air conditioning systems? Then you need a precise measuring instrument which provides you with accurate results. Because even small discrepancies can cause problems with air conditioning and ventilation systems, you cannot allow yourself to work with approximate values.

Testo measuring instruments offer thermal anemometers and vane anemometers for measuring the air speed and volume flow in ventilation ducts. These options can be connected individually. Here, the measuring instrument offers intuitive operation with clearly structured measurement menus for volume flow, degree of turbulence or cooling and heating output as well.

A wide variety of combination options are possible thanks to high-quality digital probes, to ensure you are ideally equipped for every measuring task.

If you have to measure moisture in materials, then you can also find the appropriate material moisture meter at Testo.

The following are anemometers for measuring flows and other values:

testo Smart App

One App for all applications

The testo Smart App guides you quickly and easily through measurements on refrigeration, air conditioning and heating systems.

Now new:

PRO measuring programs for increasing the efficiency of your applications

Find out more


Compatible with all Bluetooth-enabled Testo measuring instruments


Direct report dispatch by e-mail


All measurement values at a glance


Intuitive measurement menus


Free download, free use


PRO measuring programs