Designed specifically to meet the exacting requirements of today's semiconductor processes and equipment, the FC-2900 and FM-3900 are premium quality elastomer- sealed mass flow controllers and meters. These MFCs combine proven Tylan General components and techniques with innovative concepts in both mechanical and electrical design.

Autozero circuitry
Long-term repeatability is enhanced in the FC-2900 by a digital circuit which automatically resets the output to zero under no-flow conditions. This feature, standard in all FC-2900 MFCs, shifts the entire calibration curve to cancel many of the effects of temperature coefficients and calibration drift. Auto- zero can also be disabled.
Fast and slow response
The FC-2900 features 0.5 second typical step response time for short-cycle processes. A user-selectable option provides a 20%/sec ramped response for long processes.

Balanced power load
Conventional MFCs draw 100 milliamperes or more through their common lead wire because currents drawn from plus and minus 15volt supplies differ by that amount. This common lead current can produce a voltage drop which will offset both the setpoint to the MFC and its flow signal. This results in signals to the MFC that may vary significantly from those at the controlling system. This common current-induced error will also change as the MFC valve position changes in response to gas pressure or temperature. The FC-2900 solves this problem by drawing a balanced load from the two 15 volt power supplies. Common lead current is so low that it eliminates the possibility of an MFC signal differing from its controlling device. In a conventional MFC with or without autozero, this offset must be custom tuned to approximately match the voltage drop in each installation. 

Enhanced temperature stability
Improved temperature compensation reduces both zero and span temperature coefficients. This allows the FC-2900 to maintain tight control in applications, such as diffusion, where ambient temperature typically varies during the run.

Accuracy
Tylan General’s thermal differential flow sensor provides highly accurate and repeatable mass measurement of gas flow. Because the sensor measures the mass flow of gas, it is independent of pressure and temperature changes. This ensures that flow are consistent in different systems or locations.

Corrosion resistant materials
Materials in the gas path include 316L and  steel and Teflon® with a selection of Viton®, Kalrez® or neoprene seals. These materials permit use of corrosive gases, such as HCI, CI2 and NH3.