testo 420 - air capture hood

Order-Nr.  0563 4200

  • Air capture hood for larger swirl outlets for measuring air capture, temperature and relative humidity

  • Impressively light with a weight of 2.9 kg

  • Precise measurement even at swirl outlets thanks to integrated air capture straightener

  • Fast set-up, convenient operation and protocol creation on site using the App

Make sure you get the testo 420 air capture hood for larger ceiling outlets and at the same time enjoy multiple maintenance benefits on HVAC systems. Because the capture hood with the removable measuring instrument is not only exceptionally light, it also guarantees accurate air capture calculations at swirl outlets

Product Description

The testo 420 air capture hood for larger air inlets and outlets enables fast and precise compliance with hygiene guidelines and requirements concerning room air quality. It provides reliable support with the calculation of the overall air capture on HVAC systems, for instance in hospitals, office buildings or commercial buildings.
High measuring accuracy at swirl outlets thanks to air capture straightener
Air capture is frequently measured at swirl outlets. Air flows are often incorrectly measured due to the turbulent air at these outlets.

The testo 420 air capture hood means you can significantly reduce these measurement errors. The integrated air capture straightener calms the turbulence and converts it into a virtually uniform air flow. This enables accurate calculation of air capture in the 80 to 3,500 m3/h range.
Exceptionally light air capture hood with fast set-up
The air capture hood with ergonomic handles and tiltable display has an exceptional weight of less than 2.9 kg. This means that frequent air capture calculations in large rooms and measurements above head height can also be carried out reliably and comfortably. In the process, a large measuring button on the air capture hood ensures easy recording of the readings.

The dimensions of the hood are 610 x 610 mm. We offer additional hoods as accessories for further ceiling outlets. The use of our optional tripod arm is a great help for air inlets and outlets which are located very high up. It can be extended up to 3,3 metres.

The air capture hood is quick and easy to set up thanks to tension rods. The trolley which is included in the scope of delivery ensures safe transport.
Create protocols directly on site and mail them using the App connection
Take advantage of further practical functions and download our free App. Because the App connection enables mobile devices such as smartphones and tablets to be used as a secondary display and remote control via Bluetooth. This is particularly practical for using a tripod arm for high ceilings.

The App enables live measurement on HVAC systems using a start and stop function and the saving of measurement data in txt format. You can create the measurement protocol directly on site using the App. Measurement results, such as the overall air capture and the air exchange rate, can be directly assigned to customer-specific protocol templates. You can then send your readings and protocols via the e-mail function. This means you save a considerable amount of time and increase efficiency.
Air capture hood with removable measuring instrument - performance overview
The air capture hood for HVAC systems is equipped with a measuring instrument for displaying measurement data. The device can be tilted and removed for user-friendly reading of measuring values.

The testo 420 measuring instrument enables you to measure flow velocity, air capture, absolute pressure, temperature and relative humidity. The automatic zeroing ensures higher accuracy for low pressures.

All measuring values are easy to read on the large display which has an illumination function. For analyses and documentation, measurement data can be saved and measurement protocols created directly on site using the App connection. Administration of the measurement data is very easy on the PC without any additional software via the plug & play function.

The testo 420 air capture hood with its integrated measuring instrument was not just developed for air capture measurement at larger ceiling outlets. The measuring instrument can also be taken off the hood and used for pressure, flow and air capture measurements in the duct. This means you can save on the purchase of an additional measuring instrument.

You merely have to attach a Pitot tube and connection hoses (both optional) for measurements in ducts. Timed and multi-point mean calculation, as well as the combination of the two, together with simple input of the duct geometry provide you with support for measurements in ducts.


Delivery Scope

testo 420 air capture hood including measuring instrument, 610 x 610 mm hood, 5 x tension rods, USB cable, batteries, trolley and calibration certificate.
Temperature - NTC

Measuring range

-20 to +70 °C


±0.5 °C (0 to +70 °C)

±0.8 °C (-20 to +0 °C)


0.1 °C

Reaction time

45 s (t90)

Humidity - Capacitive

Measuring range

0 to 100 %RH


±1.8 %RH + 3 % of mv at +25 °C

(5 to 80 %RH)


0.1 %RH

Differential Pressure - Piezoresistive

Measuring range

-120 to +120 Pa


±2 % of mv + 0.5 Pa at +22 °C, 1013 hPa


0.001 Pa

Reaction time

1 s (t90)

Absolute Pressure

Measuring range

700 to 1100 hPa


±3 hPa


0.1 hPa

Reaction time

1 s

Volume flow

Measuring range

40 to 4000 m³/h


±3 % of mv + 12 m³/h at +22 °C

1013 hPa (85 to 3500 m³/h)

Reaction time

1 s (t90)


1 m³/h

General technical data


2900 g


610 x 610 mm (Standard hood)

Operating temperature

-5 to +50 °C

System requirements

requires iOS 12.0 or newer; requires Android 6.0 or newer; requires mobile end device with Bluetooth 4.0


EU-guideline 2014/30/EU

Battery type

Alkali manganese, mignon, type AA

Battery life

40 h

Display size


Display function

Dot matrix

Display ligthing

with illumination


Micro-USB; Bluetooth® 4.0 wireless technology

Data transfer


Radio range

10 m


2 GB (internal)

Storage temperature

-20 to +60 °C

Additional accessories and Spare parts

Rs  4,670.00
GST and accessories extra
Rs  14,840.00
GST and accessories extra
Rs  13,130.00
GST and accessories extra
Rs  36,800.00
GST and accessories extra