Vacuum or negative pressure at a flow section is:
Apressure measured always below atmospheric pressure
Bpressure measured by a Bourdon guage
Cpressure indicated by a vacuum gauge
Dalways the pressure indicated by a differential manometer
Apressure measured always below atmospheric pressure
Bpressure measured by a Bourdon guage
Cpressure indicated by a vacuum gauge
Dalways the pressure indicated by a differential manometer