Omnidirectional anemometer for low air velocity with USB output.
Swema 03 meets the requirement of ISO 7726 to be used for ISO 7730 - Ergonomics of the thermal environment:
1: The air velocity sensor must be direction independent and sensitive for low air velocity. In rooms the direction changes and the velocity is around 0.05...0.4 m/s.
2: The response time of sensor must be as short as possible.
The turbulence of air is an important component of air velocity in the draught rating formula. The room air velocity can change from 0.05 m/s to 0.4 m/s in very short time. It is important that the sensor follows these changes. ISO 7726 indicates that the desirable response time of an air velocity sensor should be below 0.2 second (90%). See technical data. Swema 03 achieves the desirable levels by using a fast microcontroller and a small sensing element. (Other larger sensors have greater inertia and therefore a longer response time).
The result is a draught sensor with especially good dynamic qualities for turbulence.
Swema 03 can be set up with multiple probes with the PC-program SwemaMultipoint
or as one probe connection with SwemaTerminal 3
. The software SwemaMultipoint can read values from Swema 03 at recommended 10 Hz with a selectable time constant set to 0.1 second.
Swema 03 can also be used with other softwares with connection to USB.
1995: Swema bought and improved a draught sensor concept originated from the Swedish Building Research Center. Probe name: SWA 01. Max velocity 1 m/s.
1997: Tested in EC (European Community, today European Union) project MAT1 CT93 0039
1999-2000: The design was improved in EC (European Community, today European Union) project SMT4-CT97-2172.
Turbulence sensivity improved. Air velocity range extended to 3 m/s. Probe name SWA 03.
2012 Electronics included in the probe with digital output. Name of this probe is Swema 03.
ISO 7730 and Low air velocity.pdf (1MB)
Air velocity: 0.05- 3.00 m/s at 15...30°C
±0.03 m/s at 0.05...1.0 m/s
±3% read value at 1.0...3.0 m/s
±0.04 m/s at 0.05...1.00 m/s
±4% read value at 1.00...3.00 m/s
Response time (90%): 0.2s
95% coverage probability in non condensing, non moist air, <80%RH, non aggressive gases
Sampling frequency: Recommended 10Hz (up to 100Hz with USB possible on some PC-installations.)
Traceable calibration certificate