Alicat ISMCW Series Controller - Intrinsically Safe Low Pressure Drop

Introuducing the new Alicat ISMCW Whisper

Alicat ISMCW Whisper series of mass flow controllers have been designed for intrinsically safe applications and processes where ultra-low pressure drops are required.

Pressure and flow rates

ISMCW Whisper series offers a minimum of 0.07 PSID / 4.8 millibar pressure drop on devices with a full scale flow rate of up to 100 SCCM. Some models offer even lower pressure drops at full scale flow, consult the spec sheet for full details.

The low pressure drop does increase for larger full scale models with the 50 SLPM model offering a maximum pressure drop of only 4.2 PSID / 290 millibar at full flow.

The ISMCW series is available with full scale flow rates from 0.5 SCCM up to 50 SLPM with typical port configurations ranging from M5 x 0.8mm female up to ¼” NPT female for higher flow models. Other thread variants are also available including BSPP, SAE, or metal face‑seal.

Custom mix and selectable gases

ISMCW devices are compatible with 98 gases and gas mixes, all of which are fully user-selectable via the push button display or digital communications. In addition the user may programme 20 user-defined mixes onto their device with each mix containing up to 5 gases with a 0.01% composition resolution.

Certification

All ISMCW are Atex and IECEx Zone 0 certified to II 1G Ex ia IIC T4 Ga / Ex ia IIC T4 Ga both with a -20 °C to +70 °C Tamb rating.

Accuracy

Accuracy varies dependant on full scale flow rates, typical accuracy is from ± 0.8% of reading and ± 0.2% of full scale with optional high accuracy up to ± 0.4% of reading and ± 0.2% of full scale dependant on model.

Communications

ISMCW offers a 4 – 20 mA control output / set point input as well as a RS-232 serial communications as standard with optional RS-485 or Modbus RTU (over either RS-232 or RS-485). Every device also comes with Alicat’s feature rich backlit monochrome display for easy setup and configuration. Ingress protection is to IP66 with electrical connections being via the DB15 connection port.

Autotune feature

Autotune feature will automatically improve the control performance of the valve and tune the control parameters of the MFC to your application. No PID control setup is needed. Typical control response times are as fast as 30 ms (T63), flow rate dependent and are fully user adjustable. The typical indication response type is < 10 ms, flow rate dependent. Typical warm-up times are less than one second!

Optional relative humidity sensor can compensate for water vapour in hydrogen production calculations, ensuring a prevised measurement of hydrogen output.

Measurements available

Standard on board measurement and calculation ensure many variables are reported including:

• Temperature
• Mass flow
• Volumetric flow
• Absolute pressure
• Gauge pressure
• Barometric pressure
• Relative humidity (with optional RH sensor)
• Dew point (with optional RH sensor)
• Percent water vapor (with optional RH sensor)
• Total mass
• Total volume