The testo 420 volume flow 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 volume flow on HVAC systems, for instance in hospitals, office buildings or commercial buildings.
High measuring accuracy at swirl outlets thanks to volume flow straightener
Volume flow is frequently measured at swirl outlets. Air flows are often incorrectly measured due to the turbulent air at these outlets.
The testo 420 volume flow hood means you can significantly reduce these measurement errors. The integrated volume flow straightener calms the turbulence and converts it into a virtually uniform air flow. This enables accurate calculation of volume flow in the 80 to 3,500 m3/h range.
Exceptionally light volume flow hood with fast set-up
The volume flow hood with ergonomic handles and tiltable display has an exceptional weight of less than 2.9 kg. This means that frequent volume flow 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 volume flow 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 4 metres.
The volume flow 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 volume flow 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.
Volume flow hood with removable measuring instrument – performance overview
The volume flow 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, volume flow, 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 volume flow hood with its integrated measuring instrument was not just developed for volume flow measurement at larger ceiling outlets. The measuring instrument can also be taken off the hood and used for pressure, flow and volume flow 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.
testo 420 volume flow hood including measuring instrument, 610 x 610 mm hood, 5 x tension rods, USB cable, batteries and trolley.
Measuring range: -20 to +70 °C
Accuracy: ±0.5 °C (0 to +70 °C) / ±0.8 °C (-20 to +0 °C)
Resolution: 0.1 °C
Reaction time: 45 s (t90)
Humidity – Capacitive
Measuring range: 0 to 100 %RH
Accuracy: ±1.8 %RH + 3 % of mv at +25 °C / (5 to 80 %RH)
Resolution: 0.1 %RH
Differential Pressure – Piezoresistive
Measuring range: -120 to +120 Pa
Accuracy: ±2 % of mv + 0.5 Pa at +22 °C, 1013 hPa
Resolution: 0.001 Pa
Reaction time: 1 s (t90)
Measuring range: 700 to 1100 hPa
Accuracy: ±3 hPa
Resolution: 0.1 hPa
Reaction time: 1 s
Measuring range: 40 to 4000 m³/h
Accuracy: ±3 % of mv + 12 m³/h at +22 °C / 1013 hPa (85 to 3500 m³/h)
Reaction time: 1 s (t90)
Resolution: 1 m³/h
General technical data
Dimensions: 610 x 610 mm (Standard hood)
Operating temperature: -5 to +50 °C
EU-/EG-guidelines: EU-guideline 2014/30/EU
Battery type: Alkali manganese, mignon, type AA
Battery life: 40 h
Display size: 3.5″
Display function: Dot matrix
Display lighting with illumination
Interface: Micro-USB; Bluetooth 4.0 wireless technology
Memory: 2 GB (internal)
Storage temperature:-20 to +60 °C
Weight: 2900 g