Sierra Instruments’Max-Trak Model 180 industrial gas mass flow controller is a NEMA 6(IP67)-compliant unit that offers accuracy of 1 percent full scale andrepeatability of 0.2 percent full scale. Coupled with Sierra’s patentedDial-A-Gas technology, the system supports 10 gases in a single instrument.Controls gas flows from 400 to less than one slpm and is onlyfive inches long and offers both digital and analog communication.