Air Flow Meter SteelMass® 640S
Inline, Totalizing Air Flow Meter Application
Accurate monitoring of peak, low flow and total gas mass flow rates is a critical part of many industrial process control systems. If you need a portable analog or digital air flow meter that easily inserts into industrial ducts and pipes (up to 72 inches), choose Sierra Instruments SteelMass® 640S.
Sierra, a leader among global flow measurement and control equipment manufacturers and suppliers, recommends its SteelMass air volume flow meter for compressed air flow, aeration basin air flow, combustion air flow, natural gas fuel flow, custody transfer and stack gas emissions flow monitoring. All of our thermal instruments feature our proprietary DrySense™ Sensor Technology backed by a Lifetime Limited Warranty.
Customize Your SteelMass Air Flow Meter
SteelMass 640S air flow meters can be customized for your air velocity and intake applications with:
- Larger probe lengths.
- High temperature option (750 degrees F).
- Self-cleaning purge option for dirty flow environments.
- Wide range of process connections (including hot tap).
- Multipoint flow averaging arrays for very large ducts, complete with a self-contained human-machine interface (HMI) panel for touch-screen field programming and system operation.
SteelMass inline air flow meters also feature Sierra's unique Smart Electronics Package for field rangeability, flow-range adjustment and validation and diagnostics. With very low pressure drops and wide turndowns, these products are hazardous-area approved by CSA and CRN (Canada); FM (USA); ATEX, CE and PED (EU); GOST R (Russian Federation); and Chinese Pattern Approval (China). Meter accuracy is +/- 1% of reading, plus +/-0.5% of full scale with repeatability of +/- 0.2% of full scale.
Our digital communications solutions offer engineers and systems integrators, full industrial system integration and networking capability with Sierra's thermal mass flow meters. Digital communications solutions include: HART, Modbus RTU, and Profibus DP. This flexibility of communication features offers turnkey solutions for integration of Sierra's thermal mass flow meters into any industrial automation system or application.
SteelMass 640S Air Flow Meters are GHG Certified
As a certified greenhouse gas (GHG) air flow meter, the SteelMass:
- Meets all requirements defined by the EPA (40 CFR Part 98).
- Is optimized for highly accurate and repeatable mass flow meters for methane (CH4) as well as N20, SF6, HFCs, PFCs and CO2, per the EPA mandate.
SteelMass is also a popular choice for landfill gas (LFG) measurement applications. LFG – a very humid, dirty gas that leaves the landfill at low pressure (20 - 40 mBarg) and about 40-60°C (100°F) – makes differential pressure (dP) devices like orifice plates unsuitable, while variable flows require a large turndown. Sierra’s 640S Insertion Mass Air Flow Meter is ideal for LFG, as it offers 100:1 turndown, has no moving parts and generates nominal pressure drop across the immersible sensor probe.
View our complete line of air and gas flow meters or learn more about selecting gas mass flow products. Contact us for additional information or get live help.
A global leader in flow measurement and control for over 35 years, Sierra instruments designs and manufactures high performance air flow instrumentation for gas, liquid and steam applications commonly found in the semiconductor, environmental, scientific research, petrochemical, energy, aerospace, and general manufacturing industries. With over 150 offices in 50 countries, Sierra is uniquely positioned to provide their innovative air flow meters and flow products with lifetime support for the leading companies of today and the growth enterprises of tomorrow.
Smart Interface Program
Click to download a zipped Smart Interface Program (Note extended download time required)
| Unique Product Features |
| • 316SS construction • Range of process connections (including hot tap) • Field Validation/Configuration • +/- 1% of reading plus +/-0.5% of full scale • Very large installed base • Removable probe for recalibration and service • Meters all process gases • 3/4” diameter insertion probe Digital communications solutions include: HART, Modbus RTU, and Profibus DP. |
Product Related Documents & Downloads
![]() ![]() Sensor Design The Key Advantaga in Thermal Mass Flow meter Perfomance March, 2007 - Instrument Design & Technology ![]() Industrial Thermal Mass Flow Meters Pt.1 / Pt.2 June, 1999 - Measurement & Control |
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![]() ![]() Air Compressor Supply Inc.: Putting a Price Tag on Compressed Air Waste The Sierra Chronicles show how Sierra has provided mass flow solutions to our customers' flow challenges for the last 4 decades. Our commitment to increasing customer productivity and efficiency has always been and will always be, the common thread. |
HART
Sierra supports HART digital communication protocol for flexible integration of our mass flow meters and controllers into any automation or control system. The HART (Highway Addressable Remote Transducer) Protocol is the global standard for sending and receiving digital information across analog wires between smart devices and control or monitoring system.
Modbus RTU
Sierra supports Modbus RTU digital communication protocol for flexible integration of our mass flow meters and controllers into any automation or control system. Modbus Protocol is a messaging structure developed by Modicon in 1979. It is used to establish master-slave/client-server communication between intelligent devices.










