Digital mass flow controllers

03/01/1999

Digital mass flow controllers

The MultiFlo elastomer digital Model 8101 and DeviceNet digital Model 8105 mass flow controllers represent a new class of MFCs for applications requiring lower-cost elastomers. True setpoint accuracy is available at ?1% setpoint and ?3s limits in both MFCs, which have a projected Weibull characteristic life of >380,000 hrs MTBF. The controllers have storage capacity in memory for up to nine surrogate and 26 process gases. Their digital electronics provide for in situ re-ranging, diagnostics, and troubleshooting, and they are available for applications with flows of 5 sccm to 30 slm. Each model uses IsoSensor, a minisensor design that produces almost no thermal siphoning effects and is attitude insensitive in all vertical-mounted applications, and has a zero drift of <0.6%. Both models come with a 32-?inch Ra surface finish and both have a high leak integrity of 1 x 10?9 atm-cc/sec (He). Unit Instruments Inc., Yorba Linda, CA; ph 714/921-2640, fax 714/921-0804.