Читать книгу Rules and Practice for Adjusting Watches - Walter J. Kleinlein - Страница 17

Two boxes are necessary for temperature testing. One fitted up to maintain a temperature of about 90° Fahr. and the other maintaining a temperature of about 40° Fahr.

The method employed in obtaining the high temperature varies in different styles of boxes, while the low temperature is always obtained through the use of ice. When only an occasional test is made, any simple method whereby approximately close results in the two extremes can be obtained, may be used. For instance, the watch may be enclosed in a tin box and placed in sand that is kept at a temperature of 90 or 95 degrees F. A thermometer placed in the sand indicates when the temperature rises too high or falls too low. The ordinary household refrigerator may be used for testing the cold. Tests by this method are advisable only for short periods and for an approximate idea as to the extent of error.

If frequent tests are made and accurate results are expected, it is quite important that the special boxes be used. Such boxes are often constructed with a capacity of four or five hundred watches, or they may be constructed to receive only half a dozen watches. Some are made with a zinc or copper tank in which warm water is placed and which surrounds the chamber in which the watches are deposited. The water is kept at the desired temperature by means of a small adjustable flame. In other instances electrical arrangements are used, in which case no water is required.

In either instance a thermostat controls the source of heat.