For over 50 years Warrick® Controls have offered dependable no-moving-parts control and monitoring of conductive liquids. Now as part of the Gems™ Sensors family, Warrick® conductivity controls continue to offer reliability, process automation, labor savings, flexibility and operator safety at economical cost. The concept is simple: take advantage of a liquid’s conductive properties to complete a circuit and cause a control relay to actuate. Use of permanently-mounted stationary electrodes gives the user precise accuracy, repeatability and no-moving-parts reliability. This simple concept has led to the development of a complete line of conductivity-based liquid level detectors, water level detectors, and control units and electrode fittings shown here. For OEM’s we also have the capability to custom configure liquid level control units and electrode fittings to meet your specific application requirements.

System Components

  1. The liquid level control unit is an electrical device with contacts that open and close in response to liquid levels sensed by the probes. Because it is wired directly to the power source and to the sensing source, it can send signals that activate or de-activate solenoids, pumps, alarms or pressure switch devices. Warrick® controls are available in many different designs and sensitivity ratings for a wide range of application requirements.
  2. The fitting is a housing that holds the probes (or floats), insulates them from the vessel, and provides a means of connection to the control. Warrick® fittings are available for single-probe or multi-probe applications, for mounting to vessels in a variety of ways, and in open or pressure tight styles.
  3. The probe is a sensor that extends downward from the fitting, with the tip positioned precisely at the level where the control should be activated. Warrick® probes are available in a variety of materials to suit different liquids and a variety of lengths to fit different depth requirements.

The liquid level control system shown here is designed for “pump up” application. The pump will start refilling the vessel when the liquid reaches the lower probe tip, then stop refilling the vessel when the liquid reaches the higher probe tip.

Types of Liquid Level Controllers:

General Purpose Water Level Controllers


General purpose controls are compact in size, provide various time delays, and solid state reliability. Applications that general purpose controls are typically seen in are single-level service, point level, valve control, differential service, alarms, and pump controls.

General Purpose Water Level Control Products:

Low Water Cut-Off Level Controls

Low water cut-off controls are designer for low-water cutoff protection. Gems low water cut-off controls meet CSD1 requirements. They also have the option of time delays and test feature functions.

Low Water Cut-Off Level Control Products:

Liquid Level Relays

These relays boost your sensor’s load handling ability in non-hazardous locations with the reliability and advantages inherent in solidstate controls.

Liquid Level Relay Products:

Intrinsically Safe Liquid Level Controls

Render any non-voltage-producing sensor, switch or conductivity electrode intrinsically safe with these relays and barriers from Gems. They amplify sensor loadhandling capabilities in a wide range of AC and DC control switching applications., and are easy to install in standard circuit boxes in non-hazardous areas. The amount of energy they send to sensors and switches within hazardous areas is insufficient to cause ignition of a specific hazardous atmospheric mixture in its most ignitable concentration. Select from a broad choice of Safe-Pak® and Warrick models.

Intrinsically Safe Liquid Level Control Products:

Liquid Level Controller Applications and Industries: