A nitrogen rotameter is calibrated by feeding N₂ from a compressor through a pressure regulator, a needle valve, the rotameter, and a dry test meter, a device that measures the total volume of gas that passes through it. A water manometer is used to measure the gas pressure at the rotameter outlet. A flow rate is set using the needle valve, the rotameter reading ? is noted, and the change in the dry gas meter reading (?V) for a measured running Lime (?r) is recorded.

The following calibration data are taken on a day when the temperature is 23?C and barometric pressure is 763 mm Hg.

(a) Prepare a calibration chart of ? versus V _std, the flow rate in standard crn3/min equivalent to the actual flow rate at the measurement conditions.

(b) Suppose the rotameter?valve combination is to be used to set the flow rate to 0.010mol N₂/min what rotameter reading must be maintained by adjusting the valve?

Transcribed Image Text:

N₂ Not to scale COMPRESSOR NEEDLE REGULATOR VALVE 5.0 9.0 12.0 TEST METER ROTAMETER Ar(min) AV (liters) 10.0 10.0 5.0 1.50 2.90 2.00