Testo manufacture and calibrate measurement instruments for HVAC, Refrigeration, Catering, Food Processing, Indoor Climate Monitoring, the Pharmaceutical industry and many more. Formed in 1957 in Lenzkirch, Germany, Testo have grown into one of the largest global franchises of their field. The UK subsidiary company, opened in 1983, is one of 32 worldwide and Testo has customer bases in 80 more.