ABSTRACT
This chapter describes a new and unique design of a primary Gas Flow Calibrator. The Aerotrak is a closed loop positive displacement system able to minimize both the quantity of gas used and the energy required to create the desired flow rate. The gas flow is created by a solid sealed piston which is moved through the length of a bored and honed flow tube with 12 RMS finish. The Aerotrak Gas Calibrator is capable of determining the changes in flowmeter calibration characteristics, where the calibration charge pressure is changed from one level to another. The entire operation of the Aerotrak is under the automatic control of a uniquely programmed Personal Computer (PC). The calibrator is pressurized at another level and an identical test is conducted. The PC has the capability of plotting both curves on the PC Screen, or generating a hard copy via a plotter.
