Starting at $92.50
  • Usually ships in 4-6 business days



  • Compact Size
  • LED Switch Indication
  • No Moving Parts
  • Wetted Materials: 316 SS/polysulfone, polysulfone, or PFA
  • Temperature Limit: 200°F (93.3°C)
  • Pressure Limit: 200 psig (13.8 bar)
  • Repeatability: ±0.02"; (0.5 mm)
  • NPN open collector switch
  • 10 to 28 VDC ower required
  • Output Signal: Vout (max) = 28 VDC, Isink (max) = 100 mA
  • Current Consumption: 35 mA maximum
  • Electrical Connections: 22 AWG, 18" (460 mm) long
  • Process Connection: 1/2" male NPT
  • Can be mounted in any position.


The W.E. Anderson OLS series are low cost, rugged optical level switches that provide rapid response while employing no moving parts for stable process control. The bright red and green LED's indicate the presence or absence of liquid for true, local indication. Three optional materials, 316 stainless steel, polysulfone and PFA provide application flexibility. Compact switch can be quickly mounted horizontally or vertically for each installation.

The W.E. Anderson OLS optical level switch employs an LED, which transmits infrared light. This light is sent through a prism and reflected back to a photo-transistor utilizing two 90° light reflections. With the prism surrounded by a gas, the light source is cast back to the photo-transistor. When a translucent liquid is introduced to the prism at or above the point where the light source makes contact with the prism, the light is reflected into the liquid, not allowing the photo-transistor to energize.


This product can be used in the following applications: