Gas mass flow meter

High-accuracy, multi-parameter flow measurement in real time

Monitor mass flow, volumetric flow, pressure and temperature simultaneously for multiple gases, or define your own custom gas mix using COMPOSER™…all on one instrument. Such versatility ensures your meter is accurate in every situation, even as your process conditions change.
Brochure Specs Manual

Making You Faster

  • Now including COMPOSER™ gas composition software!
  • 5-ms speed of response.
  • No warm-up required: ready to operate in one second.
  • Stand-alone unit: no need for computer or PLC.
  • All flow data visible on one screen (mass flow, volumetric flow, absolute pressure, temperature).
  • Digital and analog outputs.

M Standard Series

Alicat M-series mass flow meter

Alicat Scientific’s M series digital/analog mass flow meter is an accurate, repeatable, and customizable mass flow meter designed to be used in a variety of applications. Our patented laminar flow technology delivers incredibly fast and inherently linear mass flow measurement over a broad 200:1 turndown range. Ranges at flows as low as 2.5 microliters per minute and as high as 4000 slpm.
M Specs

MW Low Pressure Drop Series

Alicat MW Whisper series mass flow

Minimize system impact with pressure drops as low as 4 mbar (0.06 psid) at full-scale flows. Alicat “Whisper” Series meters enable flow measurement at near-atmospheric pressures, perfect for aerospace and environmental gas analysis applications. Max range: 0-500 slpm.
MW Specs Go to Whisper page.


MS Anti-Corrosive Series

Alicat MS-series mass flow meter for corrosive gases

Withstand corrosion caused by aggressive gases such as NH3, H2S and SiH4 with durable 316L stainless steel. All ranges available. Click the “Quick Specs” tab for a listing of included corrosive gas calibrations.
MS Specs


MB and PCU Portable Calibration Series

Alicat portable mass flow calibrator with optional backlit color display

Integrated rechargeable lithium-ion batteries make for laboratory-grade flow verification that you can take with you anywhere. May be customized as “Whisper” (MWB) or anti-corrosive (MBS) portable calibrators. Alicat’s Portable Calibration Unit (PCU) houses three mass flow meters in a single battery-powered case for the widest possible calibration range. Click here for more information about our portable meters and calibrators.
MB Specs PCU Specs Go to Portables page.


Common Instrument Options

View other available instrument options here.

L Liquid Flow Series

Alicat L-series liquid flow

Measure liquid flows with the fastest response time available in a liquid flow meter (20 ms). Available in ranges to 0-10 lpm.
Go to Liquid Meter page.

Download M-Series Meter SpecsMW SpecsMS SpecsMB Series Specs


  • Standard accuracy (NIST-traceable): +/- (0.8% of the reading + 0.2% of the full-scale range)
  • Optional high-accuracy calibration: +/- (0.4% of the reading + 0.2% of the full-scale range)
  • Accuracy specs apply to preloaded and COMPOSER™ gas calibrations.

Speed of Response

  • Typical flow reading response time constant: 5 ms (may be up to 10 ms under very low flow conditions)



  • Available ranges: any full-scale range from 0-0.5 sccm to 0-4000 slpm
  • Standard linear range: 0.5-100% of full scale, 200:1 turndown
  • 316L linear range: 1-100% of full scale, 100:1 turndown (MS series)


  • Maximum line pressure: 145 psig (standard) or 50 psig (MW series)
  • Standard pressure drop: 1-9 psi at full scale, depending upon flow range
  • “Whisper” (MW) pressure drop: 0.06-0.69 psi at full scale, depending upon flow range


  • Standard communications: RS-232 digital and 0-5 volt analog
  • Optional analog communications: 1-5v, 0-10v, 4-20 mA; secondary outputs also available
  • Optional communications protocols: RS-485, Modbus RTU (over RS-232 or RS-485), PROFIBUS
  • Standard connector: 8-pin mini-DIN
  • Optional connector: 9-pin or 15-pin D-sub connectors, configured to match any existing pinout


  • Simultaneous real-time readings of mass flow, volumetric flow, absolute pressure and temperature
  • Standard display: 2.1″ monochrome LCD digital display with touch pad interface
  • Optional 2.1″ backlit color TFT digital display with touch pad interface


  • Limited lifetime warranty
  • Meter unaffected by bumps, humidity or changes in orientation

Gas Select™ 5.0 Gas List for Alicat Mass Flow Meters and Controllers

All Alicat Scientific mass flow meters and mass flow controllers come standard with NIST Ref Prop 9 gas properties data for up to 130 preloaded gas calibrations. Users may switch between selected gases on the fly without any need for recalibration of the mass flow meter or controller. All Gas Select™ calibrations retain the instrument’s specified NIST-traceable calibration accuracy. (See individual specifications sheets for details.)

Pure Gases
Bioreactor Gas Mixes
Pure Corrosives
• Acetylene (C2H2)
• Air
• Argon (Ar)
• i-Butane (i-C4H10)
• n-Butane (n-C4H10)
• Carbon dioxide (CO2)
• Carbon monoxide (CO)
• Deuterium (D2)
• Ethane (C2H6)
• Ethylene/Ethene (C2H4)
• Helium (He)
• Hydrogen (H2)
• Krypton (Kr)
• Methane (CH4)
• Neon (Ne)
• Nitrogen (N2)
• Nitrous Oxide (N2O)
• Oxygen (O2)
• Propane (C3H8)
• Sulfur Hexafluoride (SF6)
• Xenon (Xe)
• 5% CH4 95% CO2
• 10% CH4 90% CO2
• 15% CH4 85% CO2
• 20% CH4 80% CO2
• 25% CH4 75% CO2
• 30% CH4 70% CO2
• 35% CH4 65% CO2
• 40% CH4 60% CO2
• 45% CH4 55% CO2
• 50% CH4 50% CO2
• 55% CH4 45% CO2
• 60% CH4 40% CO2
• 65% CH4 35% CO2
• 70% CH4 30% CO2
• 75% CH4 25% CO2
• 80% CH4 20% CO2
• 85% CH4 15% CO2
• 90% CH4 10% CO2
• 95% CH4 5% CO2
*These gases require MS/MCS-Series instruments.
• Ammonia (NH3)
• Butylene (1-Butene)
• Cis-Butene (cis-2-Butene)
• Iso-Butene
• Trans-Butene
• Carbonyl Sulfide (COS)
• Chlorine (Cl2), *meters only
• Dimethylether (CH3OCH3)
• Hydrogen Sulfide (H2S)
• Nitrogen Trifluoride (NF3)
• Nitric Oxide (NO)
• Propylene (C3H6)
• Silane (SiH4)
• Sulfur Dioxide (SO2), *meters only
Breathing Gases Fuel Gas Mixes Refrigerants
• EAN-32 (32% O2+68% N2)
• EAN-36 (36% O2+64% N2)
• EAN-40 (40% O2+60% N2)
• EA-40 (40% O2+60% Air)
• EA-60 (60% O2+40% Air)
• EA-80 (80% O2+20% Air)
• Heliox-20 (20% O2+80% He)
• Heliox-21 (21% O2+79% He)
• Heliox-30 (30% O2+70% He)
• Heliox-40 (40% O2+60% He)
• Heliox-50 (50% O2+50% He)
• Heliox-60 (60% O2+40% He)
• Heliox-80 (80% O2+20% He)
• Heliox-99 (99% O2+1% He)
• Metabolic Exhalant (16% O2+78.04% N2+5% CO2+0.96% Ar)
Coal Gas 50% H2+35% CH4+10% CO+5% C2H4
Endothermic Gas 75% H2+25% N2
HHO 66.67% H2+33.33% O2
LPG HD-5 96.1% C3H8+1.5% C2H6+0.4% C3H6+1.9% n-C4H10
LPG HD-10 85% C3H8+10% C3H6+ 5% n-C4H10
Nat Gas 93% CH4+3% C2H6+1% C3H8+2% N2+1% CO2
Nat Gas 95% CH4+3% C2H6+1% N2+ 1% CO2
Nat Gas 95.2% CH4+2.5% C2H6+0.2% C3H8+0.1% C4H10+1.3% N2+0.7% CO2
Syn Gas 40% H2+29% CO+20% CO2+11% CH4
Syn Gas 64% H2+28% CO+1% CO2+7% CH4
Syn Gas 70% H2+4% CO+25% CO2+1% CH4
Syn Gas 83% H2+14% CO+3% CH4
*These gases require MS/MCS-Series instruments.
• R-11 Trichlorofluoromethane (CCl3F)
• R-14 Tetrafluoromethane (CF4)
• R-22 Difluoromonochloromethane (CHClF2)
• R-23 Trifluoromethane (CHF3)
• R-32 Difluoromethane (CH2F2)
• R-115 Chloropentafluoroethane (C2ClF5)
• R-116 Hexafluoroethane (C2F6)
• R-124 Chlorotetrafluoroethane (C2HClF4)
• R-125 Pentafluoroethane (C2HF5)
• R-134A Tetrafluoroethane (CH2FCF3)
• R-142B Chlorodifluoroethane (CH3CClF2)
• R-143A Trifluoroethane (C2H3F3)
• R-152A Difluoroethane (C2H4F2)
• RC-318 Octafluorocyclobutane (C4F8)
• R-404A (44% R-125+4% R-134A+52% R-143A)
• R-407C (22% R-32+25% R-125+52% R-134A)
• R-410A (50% R-32+50% R-125)
• R-507A (50% R-125+50% R-143A)
Chromatography Gases Oxygen Concentrator Gas Mixes
• P-5 (5% CH4+95% Ar)
• P-10 (10% CH4+90% Ar)
• 89% O2+7% N2+4% Ar
• 93% O2+3% N2+4% Ar
• 95% O2+1% N2+4% Ar
Welding Gases Stack/Flue Gas Mixes Laser Gas Mixes
• C-2 (2% CO2+98% Ar)
• C-8 (8% CO2+92% Ar)
• C-10 (10% CO2+90% Ar)
• C-15 (15% CO2+85% Ar)
• C-20 (20% CO2+80% Ar)
• C-25 (25% CO2+75% Ar)
• C-50 (50% CO2+50% Ar)
• C-75 (75% CO2+25% Ar)
• He-25 (25% He+75% Ar)
• He-50 (50% He+50% Ar)
• He-75 (75% He+25% Ar)
• He-90 (90% He+10% Ar)
• A1025 (90% He+7.5% Ar+2.5% CO2)
• Stargon CS (90% Ar+8% CO2+2% O2)
• 2.5% O2+10.8% CO2+85.7% N2+1% Ar
• 2.9% O2+14% CO2+82.1% N2+1% Ar
• 3.7% O2+15% CO2+80.3% N2+1% Ar
• 7% O2+12% CO2+80% N2+1% Ar
• 10% O2+9.5% CO2+79.5% N2+1% Ar
• 13% O2+7% CO2+79% N2+1% Ar
• 4.5% CO2+13.5% N2+82% He
• 6% CO2+14% N2+80% He
• 7% CO2+14% N2+79% He
• 9% CO2+15% N2+76% He
• 9.4% CO2+19.25% N2+71.35% He
• 9% Ne+91% He

Alicat Turndown Ratio for Mass Flow

Alicat demonstrates an incredible 5000:1 turndown ratio, commanding a 5 slpm (5000 sccm) mass flow controller to control down to 1 sccm!

Ask Alicat: What Is Pressure Drop?

Pressure drop is the amount of line pressure that is permanently lost as gas passes through an instrument in a gas line. Alicat Scientific demonstrates the importance of pressure drop for gas flow processes and shows how you can greatly reduce pressure drop by using its Whisper Series of mass flow instruments.

Ask Alicat: How tough is an Alicat flow meter? (Drop Test)

We drop an Alicat portable mass flow meter onto unforgiving concrete from increasing heights to test the toughness of this product. After each drop, we compare its measurement to the pre-test baseline.


Gas mass flow meter

Alicat M-series mass flow meter

Whisper low pressure drop mass flow meter

Alicat MW-Series “Whisper” low pressure drop mass flow meter, shown with optional color display

Whisper low pressure drop mass flow meter

Alicat MW-Series “Whisper” low pressure drop mass flow meter for moderate flows, shown with optional color display

Alicat M-Series high-flow (4000 slpm) mass flow meter

Alicat M-Series high-flow (4000 slpm) mass flow meter

In the Box

Compatible Accessories:


Please contact one of our Alicat representatives for current pricing and quoting for your region, or email us to discuss your application with an Alicat sales engineer.

Filter Characterization

Characterize a filter’s flow versus pressure drop curve by fixing the differential pressure across the filter using the pressure controller. The mass flow meter displays the resulting flow rate required to attain the pressure drop.
See the full app note here.

Filter Characterization Using Differential Pressure Control

Filter characterization using an Alicat differential pressure controller

Faster Leak Testing

Establish stable pressure for the leak check by measuring pressure precisely at the device under test with Alicat’s PC3-series pressure controller with remote sense port. This method negates the pressure drop induced by the mass flow meter that is measuring the leak rate with 5-ms speed of response.
See the full app note here.

Faster Leak Testing

Leak testing using an Alicat PC3 pressure controller with remote sense port