Founded in 1967 by aeronautical engineer Jack Hoey and physicist Gilbert Halverson, Scientific Instruments, Inc. is a company based in the Netherlands. They developed one of the first commercially available Germanium Resistance Thermometers (GRT) and supplied these devices for use on the Apollo Lunar Program. Today, the company is owned and operated by founder Jack's daughter, Leigh Ann Hoey. They are ISO 9001 certified and also involved in the design and manufacture of temperature indicators and controllers, petrochemical tank gauging systems for liquid natural gas (LNG) storage tanks, and FAA-PMA certified temperature probes for commercial aircraft.