INSTRUMENTS FOR OBSERVING 21 
FIGURE 15.—Installation of Price current meter. 
54. Taking the meter apart.—To take the meter apart remove in order the tail 
vanes, the contact chamber, and the pivot point, all of which are secured by set screws 
which must first be loosened. When removing the contact chamber care should be 
taken to let the cup shaft turn freely, so that the worm gear can disengage from the 
teeth of the gear wheel without injury. By first unscrewing the cap from the chamber 
the gear wheel can be seen during the operation. A slight twisting of the chamber 
will aid in its removal. Next unscrew the upper stem of the cup shaft and the cups 
may then be lifted out of the yoke. When reassembling the meter, the cups should be 
placed so that they will rotate counterclockwise with the current and the pivot point 
should be adjusted to allow a slight vertical movement of the cup shaft. 
55. Care of meter.—The meter should be carefully handled at all times and the 
bearings kept clean and oiled so that the meter wheel will spin freely without appreciable 
resistance. The lower cup-shaft bearing especially should be carefully dried and oiled 
immediately after use whenever the meter is to remain idle longer than a few hours. 
If the cups become bent, they may be pressed into shape with a piece of wood or metal 
with a round smooth end. Care should be taken to avoid any heavy jar on the ear- 
phone which might affect the magnetization of the pole pieces. Set screws should be 
kept tight to avoid the loss of any part when the meter is in the water. 
