MW/MCW “Whisper” Series Low Pressure Drop Mass Flow Measurement and Control alicat.com/whisper Series Overview Alicat Scientific “Whisper”-Series digital mass flow meters and controllers accurately and rapidly measure or control the mass flow rate, volumetric flow rate and pressure of process gases with minimal effect on the process itself. The Whisper Series features extraordinarily low pressure drops, as low as 3.6 mbar (0.052 psi) at full scale, or 0.018 mbar when fully turned down (200:1 turndown). Low pressure drop means minimal system impact, resulting in faster mass flow measurement (<10 ms) and control (<100 ms). At the heart of Alicat’s Whisper-Series mass flow meters and controllers is a patented, internally compensated, laminar differential pressure measurement technology that yields linear results over a very wide flow range. This produces volumetric and mass flow data that is fully compensated for changes in pressure and temperature and corrected for the user’s STP. All mass flow instruments come with NIST-traceable calibration sheets. Alicat backs every mass flow instrument with generous customer support, including free technical phone support, prompt recalibration service and a lifetime warranty. Alicat Whisper-Series mass flow meters and controllers feature large integrated displays with touchpadaccessible gas selection, setpoint control and PID valve tuning. The Whisper Series comes standard with analog and RS-232 digital communications. Extensive customizations are available, including Class 1, Div 2 ATEX/CSA ratings for use in hazardous environments and battery operation for meters (MWB Series). Applications Alicat Scientific Whisper-Series digital mass flow meters and controllers are best used wherever minimal system pressure is available to be lost by mass flow instrumentation. Applications include atmospheric testing and environmental air sampling, where little inlet pressure is available. Whisper mass flow controllers make rapid leak testing a reality, even at low flow rates. Multiple gas calibrations and a low 200:1 turndown ratio allow a single Whisper-Series meter or controller to serve many applications. The Whisper Series is available in full-scale mass flow rates from 0-0.5 sccm to 0-500 slpm.

Technical Data for Alicat WHISPER Mass Flow Meters 0 – 0.5 sccm Full Scale through 0 – 500 slpm Full Scale Alicat Whisper mass flow meters are designed for low pressure drop applications. Whisper offers the lowest pressure drop available for mass flow metering or control on the market today. Standard Specifications (Contact Alicat for available options.) Performance Whisper Mass Flow Meter Accuracy at calibration conditions after tare High Accuracy at calibration conditions after tare Accuracy for Bidirectional Meters at calibration conditions after tare ± (0.8% of Reading + 0.2% of Full Scale)...