The ID- 221 operates with fluctuating liquid levels up to 45 m (150 ft), and is controlled by the analog PS-220 Controller, which has two field-adjustable alarm points:
- Low oil alarm — Detection of a predefined layer thickness of hydrocarbons
- High oil alarm — Detection of a hydrocarbon layer at a second predefined thickness
The ID-221 can detect as little as 0.3 mm (0.01 in) oil on water reliably, repeatedly, and without false alarms. It can also monitor on-line changes in oil layer thickness up to 25 mm (1.0 in). The signal controller relays are used for local and remote alarms and control. A stilling well is recommended for all ID-221 installations (available as an accessory option from GE). Continuous built-in diagnostics monitor sensor operations.
The Leakwise sensors use a patented, high-frequency Electromagnetic Absorption Technique. Each floating sensor houses a high-frequency electromagnetic energy transmitter and a receiving antenna which continuously monitor the liquid surface. Since water absorbs more electromagnetic energy than hydrocarbons, changes in the absorption rate of water indicate the presence or buildup of hydrocarbons.
The Leakwise sensors can be used to detect and monitor the buildup of free or emulsified non-soluble hydrocarbons on water and other aqueous solutions. No other oil sheen monitoring system does this.
The Leakwise ID-221 sensor detects the presence of and monitors the buildup of thin layers of hydrocarbons on water. Many petroleum and power companies use it for early detection, warning, and control of oil leaks and spills in wet sumps, tanks, and groundwater monitoring wells with a minimum water level of 30 cm (12.0 in). Other applications include hydrocarbon detection and monitoring in oil/water separators, cooling water trenches, storm water runoffs, retention ponds, boiler condensate tanks, and wastewater sewer systems.
The basic Leakwise Oil-on-Water Monitoring and Detection System includes a sensor (ID-22x) and an analog controller (PS-220). The analog controller includes two dry contact relays (4 Amp) that are usually used to turn off a pump, close a valve, etc. It also includes a third fail-safe relay (3 Amp dry contact) to indicate a system failure. The analog controller may also be ordered with a 4-20 mA output and a local bar graph display (bar graph shows a proportional measurement of hydrocarbon thickness).
For projects that have multiple sensors (more than three), it becomes economical to purchase a single digital controller that is capable of operating up to eight sensors. For large multi-sensor distributed applications, a wireless system may be the best solution.
Leakwise Sensor Highlights
For Low Maintenance
The sensor is highly resistant to coating and does not require regular cleaning. Usually an annual cleaning and calibration is adequate.
Low Detection Limit
The sensor detects sheen at 0.3 mm in thickness. Also reports oil thickness up to 25 mm with standard model — up to 200 mm linear thickness measurement available.
Programmable Detection Limit
Set points can be easily 'tuned' to meet application specifications, eliminating false positives.
Since water absorbs more electromagnetic energy than hydrocarbons, changes in the absorption rate of water indicate the presence or buildup of hydrocarbons. The Leakwise sensors can be used to detect and monitor the build-up of free or emulsified non-soluble hydrocarbons on water and other aqueous solutions. No other oil sheen monitoring system does this.