Whisper MCW–Series: Low Pressure Drop Gas Mass Flow Controllers
7641 N. Business Park Drive
85743 Tucson, AZ
Tel 520 290-6060
Whisper devices are built for processes with little available inlet pressure or a large amount of back pressure. These devices have a larger flow body and uniquely arranged laminar flow elements, resulting in pressure drops up to 10x lower than standard devices. Whisper instruments also utilize a much more sensitive pressure sensor package to take full advantage of the lower pressure readings.
Whisper™ MCW-Series performance (most products)
- Available full scale ranges: 0.5 SCCM to 1000 SLPM
- Steady state control range: 0.5% – 100% of full scale
- Standard accuracy calibration, NIST-traceable: ±0.75% of reading or ±0.1% of full scale, whichever is greater
- Optional high-accuracy calibration, NIST-traceable: ±0.6% of reading or ±0.1% of full scale, whichever is greater
- Repeatability: ±(0.2% of reading + 0.02% of full scale)
- Typical control response time: as low as 30 ms
- Warm-up time: <1 s
Whisper™ MCW-Series operating conditions
- Compatible gases: 98 pre–loaded selectable gas calibrations; additional mixtures definable with COMPOSER™
- Operating temperature: –10°C to +60°C
- Full scale operating pressure: 60 PSIA
- Full scale pressure drop (range dependent): as low as 0.07 PSID
- Max differential pressure: 15 PSID
- Proof pressure: 80 PSIA
- User selectable reference conditions (defaults): 25°C & 1 ATM (STP) and 0°C & 1 ATM (NTP)
Included with each device
- Multi-variable process measurements: Simultaneously measure mass flow, volumetric flow, gas pressure, and gas temperature.
- User changeable units of measurement: Change the unit of measurement for pressure, flow, or temperature from our extensive list of engineering units.
- Gas selectability: Select your process gas from any of the 98+ preloaded NIST-traceable gas calibrations in our gas list.
- Gas Select COMPOSER™: Define 20 custom gas mixtures of up to 5 constituent gases using our Gas Select Composer™ firmware.
- Monochrome backlit LCD with integrated touchpad: Easily read measurements using the backlit display and control configurations with the user-friendly integrated touchpad.
- User adjustable setpoint ramping & limits: Configurable ramp rates allow the process variable to be controlled as fast or as slow as desired, and configurable setpoint limits protect processes from inadvertent setpoint changes.
- User adjustable standard temperature and pressure (STP) conditions: Quickly change reference conditions without need for recalibration.
- Valve close override and valve open override: Utilize alarms to quickly vent your system or stop all flow as needed.
Build and performance options
- Communication protocols: Analog, RS–232, RS–485, DeviceNet, EtherCAT, EtherNet/IP, Modbus RTU or TCP/IP, PROFIBUS, PROFINET
- Displays: Backlit monochrome or color; integrated or panel–mount
- Process connections: NPT, SAE, AN, BSPP/G, compression, VCR, or VCO fittings
- Elastomers: Viton, FFKM, EPDM, Silicone
- Calibration: High-accuracy; custom calibration points
- Aggressive gas compatibility: Models with wetted materials compatible with many pure corrosive gases and most refrigerant gases, in addition to all non-corrosive gases and a variety of liquids also available.
Valve options & PID tuning
Your mass flow controller may be customized with one of the following valving options to ensure optimal performance under your expected process conditions.
- MCW: small proportional control valve for flow ranges of 2 SLPM and below
- MCPW: small proportional control valve with the largest orifice (not available for corrosive configurations)
- MCHW: hammerhead configuration, which pairs two small valves working side-by-side as one valve
- MCRW: nearly frictionless large Rolamite proportional valve for flow rates of 5 SLPM and above
Custom PID valve tuning ensures maximum performance for your specific process conditions.