These Pitot Tubes are designed specifically for flow measurement of dirty, particulate laden air or gas streams typical in environmental testing. Large 5/16"diameter stainless steel tubing resists plugging under harsh, sooty conditions which quickly block conventional flow sensors. Total and static pressure tubes are precisely aligned and welded together every six inches for maximum accuracy, strength and long term durability. Versatile 1/8" female NPT connections easily adapt to any type of pipe or tubing. A pair of 1/8"NPT to 3/16"I.D. tubing adapters is included plus a handy molded vinyl cap to protect tip when not in use. Supplied with complete instructions and air velocity calculator slide chart.