| 摘要 |
External monitoring and control apparatus and associated method comprising means to continuously provide a precision reference voltage to an internal monitoring instrument such as a cathodic monitoring instrument operable, in use, to monitor externally produced voltage and/or current signals indicative of rectifier current, rectifier voltage and soil potential in the system being monitored, wherein the normally continuous supply of precision reference voltage is interruptable by a Reed relay connectable in its open position to a source of incoming measurement signals indicative of current and/or voltage parameters relating to the system being monitored by the internal monitoring instrument, the arrangement being such that the internal monitoring instrument is only briefly in direct electrical contact with the system being monitored when external monitoring occurs via the external monitoring and control apparatus. |
