The testo 435 multi-function measuring instrument is available in four versions. This testo 435-1 version is the entry-level measuring instrument for adjusting and testing ventilation and air conditioning systems and for assessing air quality. Optional probes for various measurements which can be connected to the testo 435-1 are also available.
Attachable probes (optional) for assessing air quality
-  IAQ probe (Indoor Air Quality) for assessing air quality – measures CO2, air temperature, air humidity and absolute pressure
-  Ambient CO probe for CO measurement in buildings and rooms
-  Globe thermometer for measuring radiant heat
-  Temperature probe for measuring air temperature, core temperature and surface temperature


Attachable probes (optional) for adjusting and testing ventilation and air conditioning systems
-  Thermal anemometers for measuring air velocity and volumetric flow in ventilation ducts. If you also want to measure the temperature and air humidity in ducts, we recommend you use the thermal anemometer with integrated temperature and air humidity measurement
-  Vane anemometer with a small diameter (Ø 16 mm) for measuring air velocity and volumetric flow in ventilation ducts
-  Vane anemometer with a large diameter (Ø 100 mm) for measuring volumetric flow at the air outlet, also for measurements at poppet valves and ventilation grilles in combination with the testo vent 417 funnels or for measurements at swirl outlets with the volume flow straightener
-  Temperature probe for measuring air temperature, core temperature and surface temperature
-  Absolute pressure probe
Service cases to offer you space for the climate measuring instrument and your whole range of probes are also available.
The testo 435-2, testo 435-3 or testo 435-4 versions offer even more possibilities for adjusting and testing air conditioning systems and measuring air quality. Some of these are fitted with integrated differential pressure measurement. Furthermore, additional probes, such as lux probes or probes for turbulence level measurement, can be attached to these versions.
Complex technology, but really easy handling
The testo 435-1 multi-function measuring instrument is characterized by an efficient measuring process which makes any inconvenient programming of the measuring instrument superfluous: probe-dependent menus and selectable user profiles for the typical applications of “duct measurement” and “IAQ measurement” ensure the easiest imaginable handling.
It also offers easy legibility due to its large display which has an illumination function. In addition, dew point distance, min., max. and mean values are displayed as well. A solid housing provides reliable protection against impacts for the testo 435-1 multi-function climate measuring instrument.
Documentation of measurement data on site
The testo fast printer, which is available as an option, means you can create a report printout of measurement data directly on site. For a duct measurement, you can for instance print out the current readings or the min./max. values for air velocity, volumetric flow, temperature and air humidity. You can use the printout as evidence of your work.
Use the practical cyclical printing function on the testo 435-1 as well. It not only enables the printout of individual readings, but also of whole series of measurements on the testo fast printer at freely adjustable intervals (for example once a minute).
We recommend you use the testo 435-2 or testo 435-4 versions for saving, documenting and archiving measurement data. They are equipped with a reading memory and PC software.