Azbil Model HPQ-T1/HPQ-T2 Pipe-Mounted Liquid Lever Fiber Units with Built-in Amplifier provide fail-safe detection of the surface level of liquids. Just mounting the switch on a pipe, the surface of the fluid can be easily detected. Refraction-based detection ensures sufficient gain between light-ON and dark-ON light levels. The switch is also suitable for liquids with poor light transmission (such as photoresist liquid and waste fluids). Depending on the model, units fit on pipe diameters of 1/16”, 3 to 7 mm, and 8 to 13 mm. Indicator and operation selector switches are on the side. Even when gang-mounted, they can be adjusted while viewing the indicator. The same model can be used for upper or lower limit detection (For pipe diameters of 8 mm or less, please contact Azbil North America. Switches with adjustable sensitivity are also available).