DAkkS-accredited and ISO calibrations for volume and mass flow


Are you involved in the measurement of air flows and consumption in the area of air-conditioning and process air technology? As a manufacturer or user of primary elements, volume flow instruments (anemometers, vane probes, thermal probes, etc.) or ventilators, you have to ensure that your equipment is functioning reliably.


halstrup-walcher operates a calibration laboratory accredited by the Deutschen Akkreditierungsstelle GmbH in accordance with DIN EN ISO / IEC 17025 to guarantee the correct functioning of measurement systems. It is approved for calibrating a variety of measurements including flow rate (volume flow / mass flow) of the medium “air”. The reference value for the laboratory is a maximum flow velocity of 10 m/s. The test facility is therefore perfectly designed for the calibration of measurement systems in air conditioning and process air ducts.

Modern volume flow measurement facility

Modern volume flow measurement facility from halstrup-walcherzoom
Modern volume flow measurement facility from halstrup-walcher

The modern air flow measurement facility ensures reliable results and calibration processes.
It offers the following features:

  • Volume flow and mass flow measurements based on the differential pressure principle
  • The full cross-section of the duct is taken into consideration; measurements are not point-specific (friction is greater at the edges and velocity higher in the middle)
  • Generation of an even air flow with several different velocities (min. five for DAkkS-accredited calibration)
  • Regulated air volume flow from 25 to 4,500 m³/h or air mass flow from 30 to 5,400 kg/h
  • Test facility offers a measurement uncertainty of less than 1 % of the measured value (mass flow)
  • Equipped for duct diameters from 50 to 700 mm (round / rectangular) in accordance
    with DIN EN 1505 and 1506 (others on request)
  • Highest level of precision – measurements take account of the air density in the system and outside air (documented in the calibration certificate)

Calibration procedure

Der Volumenstrom- und Massenstrom Prüfstand erfasst und dokumentiert genaueste Messwerte
  • Visual inspection of the calibration object
  • Adaptation / Assembly on the test facility
  • Calibration procedure performed in accordance with the pre-defined standard (compliant with DAkkS or ISO, calibration points may also be selected by the customer)
  • Calibration certificate with target and actual values as well as statement of theuncertainty (only for calibration certificate with DAkkS accreditation symbol)
  • Calibration mark on the instrument if required

Adjustment – more than simple calibration


No adjustments are made to the test objects / instruments during a calibration. Recalibration is recommended if (external) adjustments / changes are made. Calibration is precisely adjusted to reflect the duct diameter, test object and measurement. It is offered for equipment from all manufacturers.




halstrup-walcher is accredited in accordance with DIN EN / IEC 17025.


ISO 9001

halstrup-walcher GmbH is accredited in accordance with DIN EN ISO 9001:2015.


Jörg Herfart