Volume flow hood Testo 420

Datasheet PDF | Startup Instruction PDF

Description

The Testo 420 volume flow hood (balometer) is a professional, high-precision solution designed for measuring air volume flow at large ceiling air inlets and outlets. Outfitted with an innovative integrated volume flow straightener, it significantly reduces turbulence errors typical at swirl outlets, transforming chaotic vortex profiles into uniform directional flows. Weighing under 2.9 kg, this exceptionally lightweight hood features ergonomic handles and a tiltable, removable measuring instrument that can also execute independent differential pressure and Pitot tube measurements inside ventilation ducts. Wireless Bluetooth capability streams real-time measurements directly to the Testo Smart App for live tracking, photo attachment, and instantaneous on-site PDF/Excel report delivery.

Industry Applications

• HVAC System Balancing: High-accuracy evaluation of input/output volume flows in hospitals, industrial complexes, and large commercial spaces.
• Cleanroom & Hygiene Compliance: Precise air cycling tracing to strictly verify local environmental health and target air change rates.
• Duct Pressure Diagnostics: Disconnecting the master module to perform multi-point mean pressure mappings with Pitot tubes inside technical channels.

Technical Parameters

• Volume Flow Range: 40 to 4000 m3/h
• Volume Flow Accuracy: +-3 % of mv + 12 m3/h at +22 C, 1013 hPa (85 to 3500 m3/h)
• Temperature Measuring Range (NTC): -20 to +60 C
• Temperature Accuracy: +-0.5 C (0 to +60 C)
• Humidity Range (Capacitive): 0 to 100 %RH
• Humidity Accuracy: +-1.8 %RH + 3% of mv (at 25 C)
• Differential Pressure (Piezoresistive): -120 to +120 Pa
• Differential Pressure Accuracy: +-2 % of mv + 0.5 Pa at +22 C
• Absolute Pressure Range: 700 to 1100 hPa (+-3 hPa accuracy)
• Standard Hood Frame Dimensions: 610 x 610 mm
• Total Weight: 2900 g
• Internal Memory & Interface: 2 GB internal storage, Micro-USB port, Bluetooth 4.0
• Battery Life: 40 h (4x 1.5V AA batteries)

Package Content

• Testo 420 volume flow hood body (610 x 610 mm base)
• Removable multi-parameter measuring instrument module
• Tension rods and matching transport trolley
• USB cable and batteries
• Calibration protocol