Spot On Earns UL 1203 Certification

HSI Sensing recently introduced Spot On, a new line of leverless limit switches imagined from the ground up to sense farther and faster, and last longer than any competitive switch. Now the company announces that all Spot On models come UL 1203 certified — which means they are explosion proof, dust ignition proof, and certified for all hazardous locations — at no extra charge to the customer.

“With most competitive switches, any upper tier UL certification is considered a special order and comes at an additional cost,” says Zack McGill, HSI’s head of engineering. “That didn’t make sense to us. Our products have always been known for quality, so to us there was no reason why every Spot On product shouldn’t come with the highest UL certification, right out of the box.”

This certification makes Spot On leverless limit switches ideal for even the most extreme operating environments including fluid processing, and oil and gas. The complete line includes four patent-pending models designed to tackle a wide variety of applications. HSI can also provide solutions for customers whose specifications require special wiring, housings, connectors, and more.


Headquartered in Chickasha, Oklahoma, HSI Sensing (Hermetic Switch, Inc.) is the innovative leader in the engineering and precision manufacturing of custom reed switch and sensor technology. The industry experts in solving problems for customers in challenging design applications, they also precision manufacture those solutions to ensure consistent, unmatched quality. All HSI products are made in the U.S.A.

Since 1968 HSI Sensing, an ISO 9001:2008 and AS9100 registered company, has been the premier choice for custom and standard reed switches, proximity sensors, and other sensing technologies for an array of industries including fluid control devices, reed relays, implantable medical devices, aerospace, heavy equipment, communications, transportation, and more. Their products are used in a variety of applications including commercial and military jet engines, security systems, commercial lawn mowers, external defibrillators, implantable medical devices, space station equipment, animal tracking, and more.

HSI Sensing is a privately-held company wholly owned by the employees. For more information about HSI Sensing, please call 405.224.4046 or visit