The DR-2 utilizes both zinc and silver / silver chloride reference electrodes for accuracy and longevity.
The Polatrak DR-2 CD combines the standard DR-2 dual element reference electrode with a 1 sq. meter current-density monitor, providing a compact package that gives accurate polarization data from a single instrument. The instrument may be either hardwired to a surface location or read subsea with a SunStation readout.
The sintered Ag/AgCl reference electrode provides very accurate potential data for monitoring polarization of the structure. The heavy-duty zinc-electrode element provides a reliable, long-term data source alongside the more accurate - but volatile - silver chloride. Polatrak systems allow you to tie into communication lines to provide remote cathodic-protection monitoring over existing infrastructure. Deepwater machines the polymer components in-house, allowing us to provide extensive QA/QC for our products.
Use of permanent-monitoring systems has grown recently because of increased integrity emphasis and ease of data telemetry. The DR-2 CD represents the latest innovation in cathodic-protection monitoring from the world's leading supplier of these systems.
New offshore structures
For new offshore platform jackets and drilling rigs, as well as SPAR, TLP, and FSU / FPSO structures, the DR-2CD installed as part of a cathodic-protection monitoring system will give operators the reliability of a 20-year system life. Reference electrodes can be welded at any of the main critical areas and hard-wired to the surface, integrating with existing electrical systems.
Existing offshore structures
For existing structures, the DR-2CD must be attached by RetroClamp to critical areas where a tubular member, riser or flange is present. The RetroClamp can be installed by diver or ROV, and the rugged conductor cable from the DR-2CD can be routed to the surface with standard cable clamps. The splash zone will require an I-tube for protection unless the cable can be routed through an existing J-tube.
New and existing subsea equipment
For subsea equipment without a nearby topside area to route cable, the DR-2CD must be connected to a SunStation readout monitor. The SunStation is powered by the lights from an ROV and can be pre-installed topside or retrofitted via ROV.
DR-2 CD as impressed-current CP controller
When combined with an impressed-current cathodic-protection (ICCP) system, the DR-2 CD can act as monitoring system and controller for the levels of the transformer rectifiers powering the ICCP system.
Structures with permanent cathodic protection monitoring systems can be inspected subsea much less frequently, as they will have the ability to perform interval surveys with a simple voltmeter.
The rugged design allows the DR-2 CD to be welded reliably to any new structure and wired to the surface at a minimal cost prior to the structure's deployment.
The double-steel-wire armored cable can be free-routed on offshore structures with simple bands or cable clamps, saving the cost of conduit or duct systems. Signal conductor for each of the reference electrodes, as well as the current density monito,r are all contained in a single cable.
The dual elements combine the high accuracy +/- 0.005 V of the silver / silver chloride electrode with the proven longevity of the zinc electrode, making it the most valuable reference cell available.
The DR-2 CD combines the standard DR-2 with an integrated current-density monitor (a large metal fin). The reference electrodes and the current-density monitor allow the operator to calculate data about the polarization of the structure, which is very important for asset-integrity managers