Image
  1. Home
  2. testo 420

testo 420 - Differential pressure measuring instrument

0560 0420
testo 420
testo 420
testo 420
testo 420
  • Differential pressure measurement, e.g. to check filters in air conditioning and ventilation systems
  • Calculate flow velocity and volume flow using a Pitot tube
  • Handy instrument featuring a large display and user-friendly menu guidance
  • Save measurement data for analysis and documentation
  • Use the testo 420 differential pressure measuring instrument to carry out simple, efficient tests on filters. You can also use the measuring instrument in conjunction with a Pitot tube to measure flow velocity and volume flow really easily in ventilation ducts.
    • not available
    • not available
    The testo 420 differential pressure measuring instrument is suitable for accurate differential pressure measurement up to 120 Pa, e.g. when checking filters in HVAC systems. Flow velocity and volume flow are calculated by the testo 420. The measuring instrument can also be used for absolute pressure measurement.

    Differential pressure measuring instrument with practical functions

    You can use a Pitot tube and compatible connection hoses (both optional) to measure the flow velocity and volume flow in ventilation ducts. Timed and multi-point mean calculation, as well as the combination of the two, along with simple input of the duct geometry provide you with support for measurements in ducts.

    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.

    Documenting the measurement data

    Measurement data can be stored in the differential pressure measuring instrument for analyses and documentation. It's easy to manage the measurement data on the PC without any additional software, via the plug & play function.

    testo 420 differential pressure measuring instrument including batteries and calibration protocol.

    Customers who viewed this product also viewed

  • Customers who viewed this product also viewed
    testo 510 - Differential Pressure Meter
    • Precise Differential Pressure Measurement - from 0 to 100 mbar. 
    • Versatile Application - ideal for checking HVAC filters, measuring gas flow, and static pressure.
    :
    0563 0510
  • Customers who viewed this product also viewed
    testo 420
    testo 420 - Differential pressure measuring instrument
    • Differential pressure measurement, e.g. to check filters in air conditioning and ventilation systems
    • Calculate flow velocity and volume flow using a Pitot tube
    :
    0560 0420
  • Customers who viewed this product also viewed
    testo 440 dP Air velocity and IAQ measuring instrument including differential pressure sensor
    testo 440 dP - Air velocity and IAQ measuring instrument including differential pressure sensor
     
    • Built-in differential pressure sensor – enables Pitot tube and filter measurements without additional equipment
    • Wireless flexibility – using Bluetooth® probes for hassle-free measurements up to 20 m away.
    :
    0560 4402
  • Customers who viewed this product also viewed
    testo 440 Delta P Air Flow ComboKit 2 with Bluetooth®
    testo 440 delta P Air Flow ComboKit 2 with Bluetooth®
    • Comprehensive IAQ Measurement – Measures all IAQ parameters, including flow velocity, temperature, humidity, pressure, CO2, CO, and more.
    • Integrated Measurement - enables all instruments to connect seamlessly, allowing you to capture and analyse multiple parameters.
    :
    0563 4410
  • Customers who viewed this product also viewed
    testo 440 Delta P Air Flow ComboKit 1 with Bluetooth®
    testo 440 delta P Air Flow ComboKit 1 with Bluetooth®
    • Comprehensive IAQ Measurement – Measures all IAQ parameters, including flow velocity, temperature, humidity, pressure, CO2, CO, and more.
    • Accurate Differential Pressure Measurement – Includes a differential pressure sensor for precise pressure drop and flow assessments.
    :
    0563 4409
  • Customers who viewed this product also viewed
    testo 400 Universal IAQ instrument
    testo 400 - Universal IAQ instrument
    • Comprehensive IAQ Measurement – Measures all IAQ parameters, including flow velocity, temperature, humidity, pressure, CO2, CO, and more.
    • Smart Measurement Programs – Intuitive programs for HVAC grid measurements (EN ISO 12599, ASHRAE 111), PMV/PPD, turbulence, and more.
    :
    0560 0400
  • Customers who viewed this product also viewed
    testo 400 air flow kit with hot wire probe
    testo 400 air flow kit with hot wire probe
    • Complete airflow solution – Includes probes for hot wire, vane (Ø 100 mm), and high-precision humidity/temperature measurements
    • Standard-compliant measurements – Perform grid-based volume flow assessments per EN ISO 12599 & ASHRAE 111
    :
    0563 0400 71
  • Customers who viewed this product also viewed
    testo 400 air flow kit with 16 mm vane probe
    testo 400 air flow kit with 16 mm vane probe
    • Complete IAQ and airflow kit – Measures velocity, humidity, temperature, CO₂, CO, and more with included 16 mm and 100 mm vane probes
    • Standard-compliant measurements – Perform grid-based volume flow assessments per EN ISO 12599 & ASHRAE 111
    :
    0563 0400 72
  • Customers who viewed this product also viewed
    testo 512-1 - Digital differential pressure measuring instrument with App connection
    • Versatile Measurement - of differential pressure (0 to 200 hPa) for many applications.
    • Reliable Results – Position-independent differential pressure sensor ensures precise readings.
    :
    0563 1512
  • Customers who viewed this product also viewed
    testo 400 Universal IAQ instrument
    testo 400 - Universal IAQ instrument
    • Comprehensive IAQ Measurement – Measures all IAQ parameters, including flow velocity, temperature, humidity, pressure, CO2, CO, and more.
    • Smart Measurement Programs – Intuitive programs for HVAC grid measurements (EN ISO 12599, ASHRAE 111), PMV/PPD, turbulence, and more.
    :
    0560 0400 01
  • Customers who viewed this product also viewed
    testo 400 air flow kit with 16 mm vane probe
    testo 400 air flow kit with 16 mm vane probe
    • Complete IAQ and airflow kit – Measures velocity, humidity, temperature, CO₂, CO, and more with included 16 mm and 100 mm vane probes
    • Standard-compliant measurements – Perform grid-based volume flow assessments per EN ISO 12599 & ASHRAE 111
    :
    0563 0400 74
  • Differential Pressure - Piezoresistive

    Measuring range
    +0.1 to +14 m/s
    -120 to +120 Pa
    Accuracy
    ±2 % of mv + 0.5 Pa at +22 °C, 1013 hPa
    Resolution
    0.01 m/s
    0.001 Pa
    Reaction time
    1 s (t₉₀)

    Absolute Pressure

    Measuring range
    700 to 1100 hPa
    Accuracy
    ±3 hPa
    Resolution
    0.1 hPa
    Reaction time
    1 s

    General technical data

    Dimensions
    150 x 85 x 35 mm
    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 ligthing
    with illumination
    Interface
    Micro-USB
    Memory
    2 GB (internal)
    Storage temperature
    -20 to +60 °C
    Contact Us
    Testo Ltd
    Newman Lane
    GU34 2URAlton
    HampshireUnited Kingdom
    01420 544433

    Opening hours

    Monday-Thursday: 8:30am - 17:00pmFriday: 8:30am - 16:00pm
    Image
    Blog

    Visit our blog

    © 2026