Cole-Parmer gas mass flow meters and mass flow controllers can handle a wide range of gases including nitrogen, oxygen and argon. They are available in either aluminum or 316 stainless steel bodies. Cole-Parmer gas mass flow meters can measure gas flow from 0 sccm to 1000 sL/min with high accuracy models offering ±0.5% accuracy of reading. Our gas mass flow meter output options include mass flow display, totalizer display, 0 to 5 VDC or 4 to 20mA analogue signal. Order an analogue to RS-232 converter to allow data collection and analysis on your PC.

When measuring the flow rate of a compressible gas, changes to its pressure, temperature or density will result in changes to the volumetric reading. As mass readings are largely independent of pressure, temperature and density Cole-Parmer gas mass flow meters offer an ideal solution if you expect pressure or temperature variations in your system.

To find the right flow meter for your application use Cole-Parmer's on-line flow meter quick search. Alternatively contact our Application Specialists for free technical support and let us bring over 50 years of flow control experience to help solve your application needs. Cole-Parmer offers both thermal dispersion and differential pressure gas mass flow meters.

Key Points for thermal dispersion gas mass flow meters

• Inside a thermal gas mass flowmeter, the gas is split. Most goes through a bypass tube, while a fraction goes through a sensor tube containing two temperature coils.
• Heat flux is introduced at two sections of the sensor tube by means of two wound coils.
• As gas flows through the device, it carries heat from the upstream, to the downstream, coils.
• The temperature differential, generates a proportional change in the resistance of the sensor windings.
• Special circuits monitor the resistance change, which is proportional to mass flow, and calibrate it to give a digital readout of the flow.
• The mass flowmeter is available with a built-in valve for flow-control applications. This allows for external control and the programming of a setpoint for a critical flowpoint. Most mass flowmeters also have an analogue or digital output signal to record the flowrate. The average mass flowmeter has an accuracy of ±1.5-2% of fullscale flow

Advantages for thermal dispersion gas mass flow meters

• Ability (within limitations to ignore fluctuating and changing line temperatures and pressures
• No moving parts
• Measures the mass of gas, not volume, so it's very accurate
• Accumulated flow can be logged using an optional totalizer
• Inline meters available in a range of body material
• Allows measurements of low flow rates

Disadvantages for thermal dispersion gas mass flow meters

• Gas must be dry and free of particulates
• Fairly slow response times
• Mass flowmeters must be calibrated for a given gas or gas blend

Typical Application for thermal dispersion gas mass flow meters

• Monitoring and controlling air flow during gas chromatography
• Monitoring CO2 for food packaging
• Gas delivery and control for fermenters and bioreactors
• Leak testing
• Hydrogen flow monitoring (e.g., in the utility industry)
• Control of methane or argon to gas burners
• Blending of air into dairy products
• Regulating CO2 injected into bottles during beverage production
• Nitrogen delivery and control for tank blanketing