Calibrating air flow measurement devices is a constant headache for users in the field. Peter Downing explains how sophisticated ultrasonics can overcome the problem.
A sound measuring method.
![](https://www.aivc.org/sites/default/files/default_images/default_image_5.png)
Year:
1998
Bibliographic info:
UK, Heating and Air Conditioning, October 1998, p 33.