An orifice was calibrated at 21°C and 760 mm Hg. It is to be used to calibrate a sampler at conditions of 25°C and 700 mm Hg. The flow at field conditions is 0.85 m3/min (30 CFM). (a) What is the flow rate at calibration conditions? (b) What is the flow rate at standard conditions?

Where:

Part a Part b:

Q2 = Flow 2 ? (cal. condt.) ? (STD condt.)

Q1 = Flow 1 0.85 m3/min Q2 in Part a

P2 = Press. 2 760 mm Hg 760 mm Hg

P1 = Press. 1 700 mm Hg 700 mm Hg

T2 = Temp. 2 21° + 273° = 294 K 298 K

T1 = Temp. 1 25° + 273° = 298 K 294 K