The Ultima Switch technology works on the principal of detecting a change in the dielectric constant of its environment. The incorpoarted sensors project a weak micro-electric field which is disrupted in the presence of water--- even very pure water. When the field becomes disrupted, the sensor recognizes that an activation has occurred and turns on or off, depending on how it has been wired. Petroleum products such as oil, grease, diesel fuel, gasoline, etc. have a dielectric constant well below the threshold which the sensors have been programmed to recognize, and thus do not affect the switch. This is why the Ultima Switch technology ignores these materials in the bilge and can still detect the presence of water, even if the sensors get covered with petroleum products.
• Detector cells are totally sealed and are never in contact with the water; not subject to corrosion
• Not affected by debris in the bilge
• No moving parts
• No mercury
• Activates at a water level of 2" and shuts off when water level reaches 3/4"
• 3-second time delay prevents false activation by splashes, etc.
• Rated for pumps to 20 amps at 12 or 24 volts