It has been found that poor quality air inside manometer tubing can lead to significant errors when measuring very low pressure differences, such as in a low-speed wind tunnel. The obvious question is, how could the air inside the manometer tubing be so much denser than ambient air?. In the laboratory, the situation was remedied by blowing out each section of manometer tubing with a small hand pump. The dense gas in the manometer tubing was thus replaced by fresh air, and the rrors were completely eliminated. This is recommended by the authors as a preventative step prior to any pressure measurements, whenever new manomenter tubing is being used.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering