Sierra Instruments introduces the Cal=Trak XL Primary Standard Gas Flow Calibrator for high flows up to 500 slpm. Ideal for calibration of gas-measuring instruments including mass flow meters and controllers, Cal=Trak XL offers accuracy of +/- 0.25 percent of reading. The dimensionally-based primary accuracy of the Cal=Trak XL is superior to pressure-based secondary methods and is backed by a rigorous uncertainty analysis. Like all members of the Cal=Trak Series, the Cal=Trak XL is a primary standard piston prover that operates with the press of a button—assuring end-users the ultimate in calibration accuracy, convenience, ease-of-use and productivity. At 24"W x 30"H x 12"D, Cal=Trak XL fits on any laboratory bench replacing large bell provers with one simple, integrated package. The single integrated piston chamber of the Cal=Trak XL can measure flows from 5 to 500 slpm, over a 100:1 range. Used in conjunction with our other Cal=Trak models, a metrology lab can be established capable of calibrating gas flow meters over a very broad range from 5 sccm to 500 slpm for a combined turndown ratio of 10,000:1.