Testo is a world leader in the design, development, and manufacture of portable test and measurement instrumentation and solutions. In addition, Testo is recognized as the leading worldwide manufacturer of portable combustion efficiency analyzers and air emission analyzers. Testo has become a major supplier of HVAC, critical HVAC, refrigeration, airflow, and environmental monitoring instruments for markets as diverse as chemical, food service and production, pharmaceutical and biotechnology, and residential HVAC suppliers.