COSA Xentaur COSA 707 - Manual (Page 40)

COSA Instruments USER MANUAL COSA 707
OK OK
,
change barometric pressure / area
F2 change units
F1 measurement START / STOP
F3 mode auto: automatic input of T gas (adoption measured T gas value)
PRINTER print-out actuel windows display
OK or ESC back to measurement
The Pitot tube shaft is introduced perpendicularly in to the duct, by holes made in the surface, at
selected positions.(see illustration).
The probe with the ellipsoidal nose is held parallel to and against the flow. The total pressure (+)
collected by the nose is connected to the (+) connection on the COSA 707.
The static pressure (-) collected by the static pressure intakes in the probe is connected to the -
connection on the COSA 707.
The COSA 707 will then indicate the dynamic pressure often called the velocity pressure.
The dynamic pressure corresponds to the difference between the total pressure and the static
pressure.
P dyn. = P tot. + P stat.
The calculation of the gas flow velocity occurs by following formula:
Where :
P stat << P baro