The ES-942 (12hour) is a stand-alone clock for applications not requiring GPS or temperature controlled stability. The ES-942/944 uses the AC line-frequency as a time reference or, optionally, a quartz crystal timebase may be specified. Fast, Slow and Hold controls are accessible on the top of the case.
This model includes the following options:
C - Crystal Time Base: A crystal reference is employed for those applications requiring independence from the line frequency. A trimming function is included for greater accuracy (2-3 seconds/week).
W - 3-Wire Power Cord: Recommended where static charges can occur. Standard on many units, otherwise a 2-wire cord is supplied.