Thermal Mass Flow Meters

Reduce Operation Cost with Precision Thermal Mass Flow Measurement

Sierra manufactures a wide variety of inline and insertion thermal mass flow meters.  These meters are used for precision CFM (cubic feet per minute) measurement of gas mass flow rate in light and heavy industrial applications.  Our proprietary DrySense sensor is key to our thermal 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 Certifications and Calibrations 

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)
• Major source boilers (40 CFR 63, subpart DDDDD)

National Institute of Standards and Technology (NIST) Calibrations

Calibrations are crucial for accurate thermal flow meters. These meters should be calibrated on a closed-loop gas calibration system traceable to a national standards lab. Sierra uses a cutting-edge, NIST-traceable calibration system to calibrate each thermal flow meter to the exact gas, temperature, and pressure conditions of the customer. 

The Sierra Difference

• Localized and Global Support: Sierra has technical support staff around the world able to help answer your application and product questions.  Our Field Service Engineers can also come directly to you and help with a wide range of field service needs.

• Commissioning: Sierra’s team of certified Field Service Engineers offer commissioning, training, troubleshooting, calibration, and repair services directly in the field.

• Lifetime Support: The Sierra support team is here for your product and application needs via our tech support hotline and on-site visits.

Looking for the best gas flow meter on the market? Sierra's QuadraTherm mass flow meter is the most accurate thermal flow meter in the world.

Due to its special sensor design and proprietary 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.

FAQS

Q: How do thermal mass flow meters work? 

A: Sierra’s traditional industrial thermal mass flow meters work using two sensors: a temperature sensor that monitors the temperature of the flowing gas and a heated sensor (or velocity sensor) that is heated to maintain a predefined temperature differential. The amount of heat required to maintain the constant temperature differential is directly proportional to the cooling effect of the gas molecules flowing by. This allows the sensor to calculate a mass flow measurement.Sierra’s QuadraTherm thermal mass flow meter four-Sensor thermal technology provides critical sensor inputs to a proprietary qTherm heat transfer algorithm set to instantly calculate gas mass flow rate at very high accuracies.  The innovative new sensor mechanical design coupled with qTherm provides accuracy-never before possible with thermal technology.
 

Q: What makes mass flow measurement more reliable than volumetric flow measurement? 

A: Mass flow measurement is more reliable than volumetric flow measurement because the former does not require additional compensation for pressure or temperature changes. Gases are susceptible to temperature and pressure changes that impact the volume of that gas flowing through a pipe or duct. In such a case, a volumetric meter calibrated under one set of pressure or temperature conditions will not give an accurate reading if those conditions change. A mass flow meter, on the other hand, measures the number of molecules in a pipe or duct rather than the space those molecules take up. As such, a mass flow measurement is not thrown off by pressure or temperature fluctuations. 

Useful Thermal Flow Meter Resources

• Five Ways QuadraTherm Flow Meter Technology Makes You And Your Process Smarter: Discover how to improve process efficiency, reduce costs, and find ways to meet sustainability and environmental governance regulations by selecting the right thermal mass flow meter with accurate flow measurement.

• Understanding Flow Measurement for Emissions Monitoring: Accurate flow measurement is critical to achieving boiler efficiency. You can take charge of your boiler efficiency and avoid steep EPA emission fines.

• Advances in Thermal Dispersion Mass Flow Meters - Part 1: Principle of Operation: This paper describes an advanced microprocessor-based thermal dispersion mass flow meter that uses four temperature sensing elements in its flow sensor instead of the traditional two elements and has a dry velocity sensor that uses no potting materials instead of the traditional potted velocity sensor.