This feature enables rectifiers on the same pipeline to synchronize their output and interrupt it according to a precise timing interval.
Synchronized interruption is typically required for CIPS (Close Interval protection Surveys) and DCVG (Direct Current Voltage Gradient) surveys. The interruption may be switched on and off, or the cycle changed, from a cell/mobile phone in the field (GSM versions only), from the CPSM software or online via iCPSM.
MERLIN rectifier monitors drive an external 12V relay, which can be electromechanical or solid state. They use GPS to synchronize their clocks and maintain synchronization at all times.
The option, available with 5-channel MERLIN rectifier monitors, consists of:
GPS synchronization hardware and firmware (internal to MERLIN)
External GPS antenna (combined GPS/GSM antenna also available)
External MERLIN Interrupter or mercury relay
Abriox’s MERLIN Interrupter is designed specifically for precise solid state interruption of rectifiers connected to a buried pipeline. It fails safe and switches the rectifier output loads encountered under the temperature, environmental and electrical conditions experienced in a rectifier cabinet. All MERLIN units automatically maintain synchronization with each other.
The patterns that are supported cater for both CIPS and DCVG surveys. CIPS surveys usually require the majority of the pattern to be ON to maintain the CP protection of the pipeline. DCVG surveys are the reverse and usually have a longer OFF than ON so that a short “blip” of ON can be seen by the survey tool.
The interrupter settings are specified to a resolution of 0.1 seconds (although the actual pattern precision is 1ms). The MERLIN Interrupter can also be used for switching the rectifier output on and off remotely and for instant OFF potential measurement at the rectifier.
The remote synchronized interruption feature (available on Super and Excel models only) enables rectifiers on the same pipeline to synchronize their output and interrupt it according to a precise timing interval.
An optional on-board GPS module enables precise time synchronization of all MERLIN monitors on a pipeline. It also provides a link to mapping software for accurate positioning. Compatible with all industry recognised Close Interval and DCVG survey patterns and most portable above-ground survey equipment.
Interruption may be switched on and off, or the cycle changed, from a cell/mobile phone in the field (GSM versions only), from the CPSM software or online via iCPSM.
In countries where mercury relays are allowed, these can be used instead of the MERLIN Interrupter and will offer a highly reliable, compact and cost effective solution. For very occasional use an electromechanical relay can also be used; however, outputting interrupter patterns is likely to exceed the relay contact life after only a few weeks of continuous use.