ELS-1150 – Optical Level Switch

The enhanced ELS-1150 series is the highest performing optical level switch from Gems™ Sensors. At just 1.38″ (35 mm) long, the ELS-1150 has been upgraded with a micro-processor board design to provide a wide range of capabilities including sinking, sourcing and time delay outputs. The strong fused glass prism eliminates leak potential and is capable of handling extreme temperature and pressure applications up to 2500 psi (172 bar). The ELS-1150 series is available in FM and EP versions with wide voltage ranges (ELS-1150XP). Built with solid state reliability, the sensor is available at an affordable price in nickel-plated carbon steel or stainless steel. The compact size of the sensors makes them ideal for monitoring the small, pressurized vessels found in HVAC, refrigeration and hydraulic applications. The sensors are most commonly used for low, high and intermediate level detection.

The stainless steel version, (ELS-1150SS), is excellent for applications requiring corrosion resistance and is ideal for acids, solvents and dielectric water applications. Higher temperature versions are available up to 257°F (125°C). Contact our factory experts for additional ordering information.


  • Hydraulic and lubricating oil reservoirs
  • Critical fluid level monitoring on machine tools, compressors, chillers and other industrial OEM equipment
  • Ideal unit capable of handling corrosive liquids such as: acids, solvents, and dielectric water applications
  • Medical Equipment; Anesthesia, Histology
Request a Quote
1/2" NPT
Nickel-Plated Carbon Steel or Stainless Steel
Fused Glass
170 bar Maximum
Operating temperature
-40°C to +100°C
Current consumption
Open Collector Output, 18 mA Sink,