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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
Volume flow measurement in ducts with the air velocity and IAQ measuring instrument testo 440
Volume flow measurement at outlets with the air velocity and IAQ measuring instrument testo 440
Measuring indoor air quality and comfort level using the air velocity and iaq measuring instrument testo 440
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
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
testo 440 dP Air velocity and IAQ measuring instrument including differential pressure sensor
testo 440 Air velocity and IAQ measuring instrument
K-factor measurement with testo 440 dP
Differential pressure measurement on filters with testo 440 dP
Differential pressure measurement on filters with testo 440 dP
Air flow measurements with pitot tube and tesso 440 dP
Precise, reliable measurement of all air velocity and IAQ parameters with the testo 440 dP: the multifunction measuring instrument features an integrated differential pressure sensor and intuitive operation with clearly structured measurement menus. Adjusting air conditioning and ventilation systems, monitoring air quality or carrying out comfort level measurements – thanks to versatile options for combining with high-quality, digital probes, you are ideally equipped to carry out your measuring task (please order probes separately).
  • 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.
  • Intuitive operation – with structured menus for volume flow, comfort level, and long-term monitoring.
  • Versatile probe compatibility – with simultaneous support for Bluetooth, cable, and thermocouple probes
  • USB data export – for easy reporting and analysis of up to 7500 stored measurements.
The testo 440 dP is a versatile and high-precision instrument that combines the functions of air velocity and indoor air quality (IAQ) measurement with an integrated differential pressure sensor. This enables professionals to perform tasks such as Pitot tube measurements, filter checks, and volume flow calculations using differential pressure and K-factors—all with one compact device.

With support for up to three probe connections simultaneously (Bluetooth®, wired, and type K thermocouple), the testo 440 dP ensures efficient and flexible measurement across various HVAC applications. Its intuitive menu structure supports standard-compliant measurements for turbulence, thermal comfort, long-term monitoring, and airflow, while its wireless capabilities reduce cable clutter on-site.

The device can store up to 7500 measurement reports, which can be exported via USB in CSV format for further analysis or documentation. Whether used for duct measurements, comfort studies, cleanroom monitoring, or IAQ assessments, the testo 440 dP is engineered for accuracy, ease of use, and operational efficiency in demanding environments.

Temperature - NTC

Measuring range
-40 to +150 °C
Accuracy
±0.4 °C (-40 to -25.1 °C)
±0.4 °C (+75 to +99.9 °C)
±0.5 % of mv (Remaining Range)
±0.3 °C (-25 to +74.9 °C)
Resolution
0.1 °C

Temperature - TC Type K (NiCr-Ni)

Measuring range
-200 to +1370 °C
Accuracy
±(0.3 °C + 0.3 % of mv)
Resolution
0.1 °C

Differential pressure (internal sensor) - Piezoresistive

Measuring range
-150 to +150 hPa
Accuracy
±0.05 hPa (0 to 1.00 hPa)
(1.01 to +150 hPa)
±0.2 hPa + 1.5 % of mv
Resolution
0.01 hPa
testo 440 dP air velocity and IAQ measuring instrument including integrated differential pressure sensor, connection hose, 3 x AA batteries, USB cable and calibration protocol.
 

Comfort probes

Food probes

Humidity probes

Pitot tubes

Pressure probes

Surface probes

Temperature probes

Velocity

Long-term monitoring of indoor air quality

Poor indoor air quality due to excessive concentrations of CO2 can cause tiredness, lack of concentration and even illness. With its menu for recording readings, the testo 440 air velocity and IAQ measuring instrument is ideal for monitoring the indoor air quality. Enter the measurement time and the measuring cycle – and, for example, track the change in CO2 concentration or humidity and temperature values over the course of the day. Simply choose between probes with Bluetooth or fixed cable for CO2, CO or humidity (please order probes separately).

Convenience and maximum flexibility for duct and outlet measurements

With our large range of air velocity probes (please order separately), you can carry out simple and convenient measurements even at locations that are difficult to access in ventilation ducts or at air outlets:
you will even find it easy to carry out measurements in particularly large ducts. This is because the extendable telescope on the hot wire and vane probe (Ø 16 mm) with universal handle can be further extended using the telescope extension – enabling you to attain a total length of 2 metres.
Carry out measurements at air/ceiling outlets effortlessly and without using a ladder. Fit your vane probe (Ø 100 mm) with the telescope with 90° angle and, if necessary, with the telescope extension (both can be ordered separately).
Greater freedom thanks to Bluetooth: the air velocity probes with Bluetooth have no inconvenient cable connection to the measuring instrument, and they transmit readings up to a distance of 20 m. Press the button on the probe to operate the measuring instrument – for example, to start and stop a series of measurements (timed mean calculation).
Attach the testo 440 air velocity and IAQ measuring instrument to metal surfaces (e.g. ducts) easily using the practical magnets.
Benefit from fast calculation of the volume flow: in the “volume flow” measurement menu of the multifunction measuring instrument, configure the dimensions and geometry of the duct cross-section – the measuring instrument shows you the volume flow straight away.

Turbulence measurement in accordance with EN ISO 7730 / ASHRAE 55

Determine the degree of turbulence and the draught risk in the workplace: draught restricts the comfort level and is the most common cause of complaints about the indoor climate. The turbulence probe (please order separately) measures air velocity and air temperature, and automatically calculates the draught risk and the degree of turbulence in accordance with EN ISO 7730/ASHRAE 55.
For convenient measurements at varying heights, we recommend using our measuring tripod for comfort level measurement (please order separately). This makes it very easy to position turbulence probes in compliance with the standards.

Range of probes for cleanrooms and laboratories

The testo 440 air velocity & IAQ measuring instrument is also ideal for a wide variety of applications in cleanrooms and laboratories in conjunction with the following probes:
  • High-precision flow measurement in fume cupboards with the fume cupboard probe
  • Thanks to the low start-up speed of 0.1 m/s, the high-precision vane probe (Ø 100 mm) is ideal for laminar flow measurements in cleanrooms. It is available as a variant with Bluetooth or with fixed cable
  • To measure the humidity in cleanrooms, we recommend the high-precision humidity/temperature probe (0636 9771 or 0636 9772). With an accuracy of ±(0.6 %RH + 0.7% of m.v.) (0 to 90 %RH), it also meets the requirements for humidity measurements in this particularly sensitive area
  • Use the high-precision digital Pt100 temperature probes, for example, for high-precision comparative measurements in calibration laboratories, temperature measurements in chemical laboratories or in the cosmetics industry as well as for determining the temperature distribution in refrigerators and conditioning cabinets
  • not available

Accessories

Accessories for measuring instrument

Further accessories measuring instrument/probes

Transport and Protection

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Testo Ltd
Newman Lane
GU34 2URAlton
HampshireUnited Kingdom
01420 544433

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