The Testo 400 is the universal measuring instrument for all TAB / Commissioning and IAQ professionals. Measure, analyze and document Air flow, air pressure, IAQ and comfort level parameters using just one instrument – simply, conveniently and in compliance with the standards. High-quality measuring technology, intuitive measurement assistants, versatile documentation options and a comprehensive selection of air flow, comfort and IAQ probes make the Testo 400 the perfect partner for your day-to-day work.