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For Those Who Demand Precision Gas Mass Flow Measurement

Thermal Mass Flow Meters

With North America's #1 selling thermal mass flow meter (Flow Research, Boston, MA.), customers can enjoy the many benefits of thermal technology—wide turndown ratio, very low pressure drop, no moving parts, application flexibility, and a direct digital gas mass flow rate measurement. All of Sierra's thermal mass flow meters deliver long-term stability with patented no-drift DrySense™mass flow velocity sensor that allows for reliable In-Situ Calibration Validation backed by a lifetime sensor warranty.

Watch Video: How Thermal Mass Flow Technology Works

Boiler MACT Certified
Thermal mass flow meters are also ideal for compliance for Boiler MACT regulations for inlet fuel measurement for area source boilers (40 CFR 63, subpart JJJJJJ) and for major source boilers (40 CFR 63, subpart DDDDD). Learn More

View Selection Charts:    S-Series     iSeries QuadraTherm

Precision Measurement Reduces Operation Costs & Increases Throughput

Sierra manufactures a wide variety of inline and insertion thermal mass air flow meters for precision CFM (cubic feet per minute) measurement of gas mass flow rate in light and heavy industrial applications including energy management, oil & gas, and research applications. Our proprietary DrySense sensor is key to our thermal mass flow meter stability and offers customers:

  • Immunity to cracking and shifting of the sensor over time
  • Maximum sensitivity, reproducibility
  • Ultimately greatly improved CFM air flow meter accuracy

Sierra's QuadraTherm mass flow meter is the most accurate thermal flow meter in the world.

Due to its special sensor design and proprietary Raptor II Flow Engine, QuadraTherm is now the only thermal flow meter that can be field-updated with new gas compositions without sending the meter back to the factory. Learn More about qMix. Watch Video.

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BoilerTrak 620S-BT

Insertion Thermal Mass Flow Meter for Boiler & Heater Efficiency

  • Optimized natural and propane measurement for 1, 2, 3, 4 inch sch. 40 pipe sizes
  • Wide flow ranges from 0 to 42,000 scfh
  • Easily install in the field or retrofit
  • Certified for GHG measurement meeting EPA (40 CFR Part 98)
  • Boiler MACT certified for area source boilers (40 CFR 63, subpart JJJJJJ) and for major source boilers (40 CFR 63, subpart DDDDD) Learn More
  • Fast delivery—ships next-day from stock 
FastFlo 620S

Fast-Response Insertion Thermal Mass Air Flow Sensor

  • Increase efficiency with fast response time within 200 milliseconds
  • Optimized air, nitrogen, and inert gas measurement for 1, 2, 3, 4 inch sch. 40 pipe sizes
  • Wide flow ranges from 0 to 42,000 scfh
  • Easily install in the field or retrofit
  • Fast delivery—ships next-day from stock
QuadraTherm® 640i

Industry's Most Accurate Air / Gas Thermal Insertion Mass Flow Meters

  • Achieve high accuracy +/- 0.75% of reading
  • Eliminate drift with patented DrySense™ sensor
  • Validate in the field for easy in-situ calibration
  • Use qMix software to easily change gas composition in the field and retain accuracy
  • Backed by lifetime sensor warranty
  • Boiler MACT certified for area source boilers (40 CFR 63, subpart JJJJJJ) and for major source boilers (40 CFR 63, subpart DDDDD) Learn More
QuadraTherm® 780i

Highest Air/Gas Mass Flow Measurement Accuracy in Industry

  • Achieve the highest accuracy +/- 0.5% of reading
  • Eliminate drift with DrySense sensor
  • Reduce straight-run requirements with built-in flow conditioning
  • Needs only 1-diameter up and zero downstream diameters
  • Validate in the field for easy in-situ calibration
  • Backed by lifetime sensor warranty
  • Boiler MACT certified for area source boilers (40 CFR 63, subpart JJJJJJ) and for major source boilers (40 CFR 63, subpart DDDDD) Learn More
SteelMass 640S

Accurate Metering of Peak, Low Flow and Total Mass Flow Rate

  • Insertion, totalizing air/gas mass flow meter
  • Eliminate drift with patented DrySense™ sensor
  • Increase flexibility with low pressure drop, high turndown
  • Validate in the field for easy in-situ calibration
  • Backed by lifetime sensor warranty
qMix™ Gas Mixing Feature

Field-Update For Gas Composition Changes

  • Powerful, gas mixing software to create custom gas mixtures in the field
  • Free BETA trial with every QuadraTherm® thermal mass flow meter
  • Maintain flow meter accuracy if gas composition changes
  • No need to send unit back to the factory if gas composition changes
  • Avoid costly recalibration
FlatTrak 780S

Inline Thermal Mass Flow Meters with Flow Conditioning

  • Reduce straight-run requirements with built-in flow conditioning
  • Eliminate drift with DrySense sensor
  • Needs only 3-diameters up, zero downstream
  • Validate in the field for easy in-situ calibration
  • Backed by lifetime sensor warranty
MultiTrak 670S

Multi-Point Gas Mass Flow Meters for Large Ducts and Stacks

  • Compensates for flow profile changes with up to 4 sensor points
  • Exceeds in applications with non-uniform flow profiles, low pressure drop, high turndown
  • Eliminate drift with patented DrySense™ sensor
  • Manage multiple inputs with easy-to-use touchscreen HMI display interface
  • Backed by lifetime sensor warranty
ChlorineTrak 760S

Cost-Effective Chlorine Gas Mass Flow Meters Made From Kynar

  • Cost-effective solution for chlorine injection market
  • Offers corrosion-resistant Kynar flow body at economical price
  • Rugged, no drift DrySense Hastelloy sensor
  • Validate in the field
  • Backed by lifetime sensor warranty
FlatTrak 780S-UHP

Industry-Choice For Bulk High Purity Gas Custody Transfer To Semicon Fabs

  • Optimized for bulk ultra high purity (UHP) gas custody transfer
  • Direct mass flow measurement
  • No moving parts, 100:1 turndown, low pressure drop
  • Reduce straight-run requirements with built-in flow conditioning
  • Validate in the field for easy in-situ calibration
OEM Probe Only Thermal Sensors

Custom Packaged Thermal Mass Flow Sensors

  • Mass flow sensor probes to fit your OEM needs
  • Wide flow range from 0 to 20,000 sfpm
  • Increase flexibility with low pressure drop
  • Turndown: 1000:1 
  • Patented DrySense™ sensor
  • Backed by lifetime sensor warranty
Flow Totalizer

Four Multi-Gas Flow Totalizers for the QuadraTherm® Thermal Mass Flow Meter

  • View and totalize four gases with one instrument
  • Totalize multiple gases indepentent of eachother
  • Accurately monetize and allocate gas usege

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