HSI Sensing provides custom and standard switching and sensing solutions. HSI Sensing manufactures reed switches and proximit ... y sensors. These devices complete electrical circuit paths when magnetism is placed in close proximity to the switch or sensor. Our production process is very precise and known for making the most difficult types of switches. We manufacture reed switches small enough to fit inside a heart pacemaker as well as sensors which meet tough military standards for installation on aircraft engines and controls. Customers choose us for our outstanding reputation in product reliability, quality, special characteristics and customer service. Our product is sold throughout the world. Many customers turn to us because we specialize in the difficult-to-manufacture products. Our custom design capability and quick response times are the keys to our success. HSI Sensing began manufacturing reed switches in 1968. Continuous growth and facilities expansion have characterized the past 40 years. Manufacturing moved to our present location in 1976, and the physical plant has been expanded three times since then. The last expansion in 1998 added 15,000 square feet of manufacturing space, including a state-of-the-art electroplating facility. read more