Absolute calibration of condenser transmitters

Several methods have been used or proposed for the calibration of the Wente condenser transmitter. The methods falling under the two classifications conveniently designated “constant pressure” or “pressure” calibration and “constant field” or “field” calibration are most useful and amenable to measurement. Which of these two calibrations is more significant depends on the particular use made of the transmitter. In the following pages the methods now used or proposed are reviewed and the advantages or disadvantages of each from the standpoint of transmitter application are discussed.