Question

5. A venturi flow meter is to be used to measure the flow of air at low velocities, with air mass flow rate being given by 11/2 CA 2P (p2) RTPP2) where C is an empirically determined discharge coefficient, A is the throat flow area, pi and pp are the upstream and throat pressures, Ti is the absolute upstream temperature, and R is the gas constant for air. We want to calibrate this meter and to determine C to within 2%. For the following nominal values and estimated uncertainties: P 30 0.5psia 11 70 3°F A 0.750.001 in What is the allowable percentage uncertainty in the m measurement? That is, how good must the mass flowmeter used in the calibration process be?

Answer 1

Solution -Fom the iven exbiuuion, we can find fllouin RT fT, Fm Uㅅth9 ểmor pro pagation formula n o w qustion, we can wyute

Divide by i both sides 2. 6.2ST, b.15 O.2S 6.2S pencentaga uncuvlanty i'n ri maswament елс x700 13.057.