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TMFM-F Thermal Mass Gas Flow Meter

Precision Measurement for Air, Nitrogen, and Other Industrial Gases

2026-10-09

You're measuring compressed air. You're monitoring nitrogen. You're tracking natural gas consumption. You're controlling combustion air.

One wrong reading – and your energy accounting is off, your process control fails, or your safety margins are compromised.

When You Need Direct Mass Flow – Not Volume

Most gas flowmeters measure volume. But gas volume changes with temperature and pressure. You end up compensating, calculating, and guessing.

The TMFM-F measures mass flow directly – no compensation, no calculation, no estimation.

It uses the constant temperature difference principle. Two platinum resistance sensors measure the heat transfer as gas flows past them. The result is direct mass flow – the number that actually matters.

Built for the Gases That Matter

Your Challenge	TMFM-F Answer
Compressed air	Direct mass measurement – no pressure compensation needed
Nitrogen, oxygen, argon	All gases except acetylene – one meter for most industrial gases
Natural gas, LPG, biogas	Accurate mass flow for combustion control and billing
Wide pipe sizes	DN10 ~ DN4000 – from small tubes to large ducts
Wide flow range	0.5 ~ 100 Nm/s – low flow to high velocity
High temperature	Standard -10~+200°C; high-temp version up to +350°C
High pressure	Up to 4.0 MPa – handles pressurized gas lines
Fast response	1 second – keeps up with changing process conditions
Remote monitoring	4~20mA, RS485, HART – integrates with any control system
Hazardous areas	IP67 protection – reliable in harsh environments
Display options	LCD display – local readout of mass flow, volume flow, total, temperature

Why Thermal Mass – Not Vortex or Orifice

Meter Type	Limitation	TMFM-F Advantage
Vortex	Requires minimum Reynolds number, pressure drop	Lower flow capability, no pressure drop from bluff body
Orifice	High pressure drop, limited range	Low pressure drop, wide turndown
Turbine	Wears, clogs, limited to clean gases	No moving parts, handles dirty gases
Ultrasonic	Expensive, sensitive to particulates	Lower cost, handles particles
Coriolis	High cost, size limitations	Lower cost, larger sizes available

Key Specifications

Parameter	Value
Product Name	Thermal Mass Gas Flow Meter
Model	TMFM-F
Medium	All gases (excluding acetylene)
Accuracy	±1.0% (some models ±1.5%)
Caliber Range	DN10 ~ DN4000; DN25 ~ DN2000
Flow Velocity	0.5 ~ 100 Nm/s
Working Temperature – Sensor	-10 ~ +200°C (standard); -10 ~ +350°C (high temp)
Working Temperature – Converter	-10 ~ +45°C
Working Pressure	≤2.5 MPa / ≤4.0 MPa
Power Supply	DC24V or AC220V (≤18W all-in-one); AC220V (≤19W split type)
Response Speed	1 second
Output Signal	4~20mA (photoelectric isolation, top load 500Ω); RS485; HART protocol
Pipeline Material	Carbon steel, stainless steel, plastics
Display	LCD, four lines
Display Contents	Mass flow, standard volume flow, accumulated flow, standard time, running time, media temperature, standard flow rate
Protection Grade	IP67
Converter Material	Stainless steel
Material	SS304 / SS316L
Warranty	1 year
Customization	OEM, ODM, OBM

What Sets TMFM-F Apart

Feature	What It Means for You
Direct mass flow	No temperature/pressure compensation – what you read is what you get
Constant temperature difference principle	Accurate, stable, repeatable measurement
1-second response	Keeps up with changing process conditions
Wide caliber range	DN10 ~ DN4000 – from small tubes to large ducts
Wide flow range	0.5 ~ 100 Nm/s – low flow to high velocity
High temperature option	Up to +350°C – handles hot process gases
High pressure	Up to 4.0 MPa – handles pressurized gas lines
Multiple outputs	4~20mA, RS485, HART – connects to any control system
LCD display	Mass flow, volume flow, total, temperature – all visible locally
IP67 protection	Dust-tight and water-resistant – reliable in harsh environments
SS304/316L construction	Compatible with corrosive and high-purity gases
Split type available	Converter can be mounted remotely – flexible installation

Typical Applications

Industry	Application	Why TMFM-F
Compressed Air	Air consumption monitoring, leak detection, billing	Direct mass flow, wide range, low pressure drop
Natural Gas	Combustion control, custody transfer, boiler feed	Accurate mass flow, high pressure capability
Chemical	Nitrogen, oxygen, hydrogen, CO2, argon measurement	Wide gas compatibility, SS316L
Pharmaceutical	Clean gas, process gas, nitrogen blanketing	Hygienic, accurate, traceable
Food and Beverage	CO2, nitrogen, compressed air	Hygienic, accurate, reliable
HVAC	Air flow, combustion air, exhaust monitoring	Wide turndown, low pressure drop
Environmental	Biogas, landfill gas, emissions monitoring	Wide range, reliable
Metallurgy	Oxygen, nitrogen, argon, hydrogen	High temperature, high pressure
Energy	Biogas, syngas, natural gas	Accurate mass flow, remote monitoring

One Question

Would you rather compensate for pressure and temperature – or measure mass directly?

Compensation introduces error. Calculation takes time. Estimation leads to disputes.

Direct mass measurement eliminates the guesswork.

The TMFM-F gives you the number you can trust.

Ready to specify the TMFM-F for your application?

Contact us with your gas type, flow range, pressure, temperature, pipe size, and communication requirements. We'll recommend the right configuration and provide a quote within 24 hours.

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Shanghai Cixi Instrument CO.,LTD was founded in 2008 and is located in Shanghai Songjiang industrial park. We are the professional flow meter manufacture who integrate R&D, production and sales as one manufacturers.