Humidity Recorders

U R I N G recent years, the study of atmospheric conditions and their bearing on various industrial problems from the standpoint both of their effects on human efficiency and on manufacturing processes, is a matter that has received much attention, and the use of air conditioning systems, which have been developed in the last few years, has resulted in greatly improved working conditions, as well as in increased outputs of manufactured products of better quality than obtainable when air conditioning was not employed. It is not so well appreciated, perhaps, that atmospheric conditions have a material effect upon the operation of intricate electrical and mechanical apparatus, such as those found in telephone systems. Water vapor, and both gaseous and solid impurities in the air, hasten oxidation and corrosion of metals and also reduce the value of the insulation afforded by insulating materials. These effects usually are greatly accelerated if the temperature is high and if the materials are subjected to differences of electrical potential. Telephone apparatus and equipment consist of combinations of materials which are subject to both of these effects and, in general, the parts are small and the materials used in making them must be carefully chosen with regard to the necessary physical and electrical properties required for proper functioning of the apparatus. Therefore, the severe atmospheric conditions, which may be encountered in service, either must be eliminated by the use of air conditioning systems or the apparatus must be designed to withstand those conditions.