ONE OF THE MOST consistently difficult problems in the textile industry is the measurement of moisture for the assessment of value of material bought or sold on a dry basis. Complete solution of this problem involves a more complete knowledge of the relation of the water and textile fiber than is available. Complications exist in the many forms of water known to be associated with natural and synthetic fibers. Adsorbed, absorbed, and chemically bound portions contribute differently to different methods of estimation of total moisture content. The method of assessing moisture which is the oldest and best known is by loss-in-weight during drying, here designated as the oven method. This method is not only time-consuming but is also unsatisfactory in many instances, and particularly with fabrics because of the necessity of cutting samples. Another is measurement of some electrical property, such as resistance, impedance, capacitance, or dielectric constant, which shows an appreciable change with change in moisture content of the sample. The oven has more apparent validity in its direct measurement of amount of water volatilized, but it is only an arbitrary standard. Calibration of another method against oven moisture should, therefore, provide an alternate arbitrary standard which could be considered an equally good measurement. The problem of measurement of a quantity whose exact relation to a desired property is not clearly defined may seem, at first glance, to be unusual. However, further consideration will undoubtedly provide, in the mind of any experimentalist, many similar instances. This phase of the problem will therefore be dismissed without additional discussion. Calibrations of several types of electrical meters intended for use in measurement of moisture in textiles have previously been discussed (3, 4, 6, 7). Variables which produce a major change in the dependence of meter readings upon the moisture, as measured by the oven method, have been emphasized, particularly in the second and fourth papers of