At one of the largest air calibration facilities in the world, we conduct first-time verification, control and recalibration of volume, mass, and dP meters using atmospheric air.
Meets your air calibration needs and provides accurate results
Fourteen metres long and 1,8 metres high, our airflow calibration facility is one of few to offer a flow range capacity from 65 (Q-min) to 25000 m3/h (Q-max).
The air facility consists of five parallel reference lines and a measuring line in series where the meter under test (MUT) is located. The airflow facility operates according to the suction principle under atmospheric conditions. Two Revolution Per Minute (RPM)-controlled centrifugal blowers draw air from the calibration room through the meter during testing and then through the reference strings containing the working standards further downstream.
Flow distribution:
(BU201) Blower A: Supplies WS201, WS202, and WS203 with air flow
(BU202) Blower B: Supplies WS204, and WS205 with air flow
Calibration of all types of air and gaseous flow meters
The air calibration facility can handle all flow meters for measuring air and other gasses, including USM, turbine meters, swirl meters and coriolis meters up to 50" in diameter.
Air calibration specialists at your service
As an impartial and independent calibration service provider, we maintain and develop a technological infrastructure of unique facilities, technologies, and competencies for society and business.
Contact us to find out what we can do for you.
Look around the Bulderbaan airflow calibration facility
The Bulderbaan facility consists of two blowers, butterfly valves, four working standards (WS) and POV valves and is easy to attach to spools and adaptors. It is approved by the Bureau International des Poids et Mesures (BIPM), the international organisation established by the Metre Convention to deal with matters related to measurement science and standards.
The air facility consists of five parallel reference lines and a measuring line where the meter (in yellow) is located during testing.
The Bulderbaan operates using atmospheric air in the flow range of 65-25000 m3/h, Ucmc 0,23%.
We use the butterfly valves POV201-205 as regulators to control the flow through each corresponding working standard (WS). They also work as shut-offs to control the flow distribution, ensuring that a single reference string can be used, as can multiple ones in parallel if needed. Relevant reference strings are chosen based on flow rate requirements and meter size.
After each working standard and Meter-Under-Test (MUT), a thermistor measures the air temperature under calibration so that the results can be corrected for temperature differences between the MUT and the working standards.
Similarly, a differential pressure transmitter PDT201 measures the pressure differences between the working standards, MUT and ambient, to enable the correction of pressure differences.
The error is then determined by comparing the indicated output of the MUT to the actual real flow. The working standards define the real flow with the appropriate corrections in terms of temperature and pressure differences throughout the loop.
Before calibration can begin, we condition the meter and the selected working standards for at least 5-20 minutes. We perform additional conditioning when changing flow rate and/or operational standards to stabilise the loop temperature and pressure.
We perform the calibration in descending order starting with the highest specified flow rate.
We can adjust the MUT after determining the error reading at each flow point. The adjustment is meter-specific (polynomial, linear or point-to-point).
