testo 6448 persluchtdebietmeter met buissensor DN40 - DN250testo 6448 compressed air meter with bar probe for determining, monitoring, controlling and logging compressed air consumption, selectable diameters DN40 (1 ½″) / DN50 (2″) / DN65 (2 ½") / DN80 (3") / DN100 (4") / DN125 (5") / DN150 (6") / DN200 (8") / DN250 (10"), with analog, pulse and switching output.