Jenco Instruments was founded by Mr. John Jen over 40 years ago on the idea that advances in semiconductor chips and circuit boards can play major roles in miniaturizing water quality instruments while increasing ease of use, features and accuracy. That idea led to the creation of the very first portable digital pH meter and was sold under Cole-Parmer's private brand. Today the same innovative spirit is prevalent in their line of water quality instruments which now spans pH, ORP, conductivity, dissolved oxygen, ion and temperature meters, testers, portable, benchtops and online analyzers. Though Jenco remains a family owned business and is small compared to consolidated multinational corporations, it is proud that its products can be found in research facilities, universities, manufacturing facilities, municipalities and homes all over the world. The EPA, NASA, Anheiuser-Busch, Kraft Foods and thousands of other companies trust their water quality readings to Jenco. All Jenco meters are designed and manufactured in its ISO9001 and IECQ Hazardous Substance Process Management certified manufacturing facility. This same Jenco facility also designs and makes products for other high end water quality manufacturers. Jenco is located in San Diego, California.