| 摘要 |
A controller for well installations which responds to external signals originating from system monitors. This response may be modified by operator inserted delays or may be utilized to carry out a SET function wherein all signals are rejected until an externally derived RESET signal is received. A priority protocol is provided with respect to the SET and RESET functions. The circuit of the controller is housed within a circuit housing which includes a polymeric seal and operates in conjunction with a sealed keypad. This circuit housing is incorporated within a principal housing and a positive pressure is maintained within that principal housing to assure the integrity thereof.
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