Detect chemical level with infrared light to avoid false switch activation caused by vibration in your tank. Also known as optical switches, these sense the level by reflecting light into a receiver that sends an output current to activate an alarm or control circuit. They are sensitive to light and should be shielded or used in enclosed tanks. Mount them horizontally or vertically.

SPST-NO switches activate when the tip is submerged in liquid and light stops reflecting into the receiver.

SPST-NC switches activate when the tip is exposed to air and light reflects into the receiver.

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Use high-frequency sound waves to detect chemical level. This switch has three relays that can be programmed for multiple set points. Use it to activate several alarms or to automate tank filling and emptying. It’s rated NEMA 4X for protection from corrosion and washdowns.

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Measure the level of conductive liquids without drilling a hole in your tank—these switches mount to the outside of the tank and track the capacitance between them and the tank’s contents. Use them on nonconductive plastic or glass wall tanks; they’re not compatible with metal tanks. They automatically adapt to your tank’s wall thickness, making them ready to use. These switches only respond when the liquid reaches the desired level, so foam and residue on the top of the liquid won’t trigger them early. For even more challenging setups, such as those with thick, sticky fluids, or if your tank has walls as thick as 10 mm, you can teach these switches to avoid false detections. All have LED indicators to show their power and output status.

Made of plastic, their body is chemical resistant and NEMA and IP rated, so it keeps out dust and dirt, as well as drips of oil and jets of hot water. UL listed, C-UL listed, and CE marked, they meet U.S., Canadian, and European Union safety standards.

Mount these switches directly on your sight glass using their adhesive back or use the included mounting bracket if you’ll need to remove them frequently. They also include foam pads for mounting them using straps around the outside of your tank.

PNP switches communicate with your system by sending a positive signal. NPN switches send a negative signal to communicate with your system.

Switches with an M8 4-pin connection have a standard plug that’s easy to connect. Switches with wire leads need to be hardwired, so use them in applications where you won’t move them often.

For technical drawings and 3-D models, click on a part number.