The general study of the Gow-Mac density balance has been continued on the basis of experience gained in the first two studies (4), (5). It has been possible to determine precisely certain aspects of the behavior of the balance, in particular: The effect of the principal parameters, such as nature of the carrier gas, reference and measuring circuit flow rates, temperature, etc., on sensitivity of the detector. The dynamic range of linearity, by searching for causes of background noise with different carrier gases. The quantitative response for all solutes, no matter what the carrier gas. The principal characteristics of the Gow-Mac balance being known, it should be possible to prove the capability of the detector not only in direct operation but also in use as a standard detector.