Sigma Control Systems: Relays, Electrodes, Fittings and Control Panels
The Objective: Accurate and dependable control of liquid levels can be essential to prevent the release of pollutants, maintain proper flow of process liquids, prevent loss of expensive materials and to protect employees and equipment.
The Technology: Conductance level control systems utilize the capability of the liquid to conduct a small electric current between electrodes installed at a predetermined level to energize or de-energize a relay.
Applications: High or low level alarms or controls for boiler, process and storage tanks; activation of sump pumps; and process controls including regulating the water flow in cooling towers. Key element of the Conductance Level Control System for liquids is the relay that is activated when the liquid level reaches or falls below the tips of the electrodes.
Sigma Controls relays can be ordered separately or as part of the system. Sigma's relays come as plug-in modules or as open circuit boards ready to be wired into the control panel. The relays come in two models: single pole, single throw and double pole, double throw to handle all applications. The standard relay can be used for either differential or single-level control. The unit uses a standard 8-pin socket which can be purchased as an option. Sensitivity for the standard model is up to 50K OHMS.