Many industrial conditions require the safe and accurate measurement of the mass flow rate of gases. If you are wondering, “what is a thermal mass flow meter?” you have come to the right place. In this guide, we explain the working principles, features, applications, and benefits of thermal mass flow meters.
What is a Thermal Mass Flow Meter?
A thermal gas mass flow meter is a device that provides accurate readings of the total mass flow rate of a gas. This type of flow meter utilizes the thermal sensing principle to measure a wide variety of gases, often independent of temperature or pressure. The devices are commonly available in inline or insertion models to ensure that gases can be measured accurately and reliably in any setting.
How Does a Thermal Mass Flow Meter Work?
A thermal mass flow meter relies upon convective heat transfer to measure the flow rate of gas. The device is equipped with a thermal mass flow sensor that consists of two Resistance Temperature Detectors (RTDs). The Reference RTD measures the gas temperature while the instrument electronics heat the mass flow sensor to a constant differential temperature above the gas temperature. The Reference RTD also measures the cooling effect of the gas flow. The mass flow rate is determined by measuring the electrical power required to maintain a constant temperature differential.
Thermal Mass Flow Meter Features
Thermal mass flow meters are available in a variety of designs, and most have a sensor, display, data output, and choice of communication system. Additionally, most thermal mass flow meters are available in inline or insertion models. Some thermal mass flow meters are available in remote versions.
Across the board, thermal mass flow meters provide negligible pressure drop, wide measurement range, sophisticated calibration systems, low-end sensitivity for leak detection, sturdy construction, and stainless steel design. The devices typically do not have any moving parts which increases the longevity of the instrument.
The highest quality thermal mass flow meters are equipped with robust sensor designs, nuanced gas selection menus, data loggers, advanced timers, rotatable problem, varied power inputs, advanced software, high and low alarm limits, and more.
Thermal Mass Flow Meter Applications
Thermal mass flow meters can be used in a variety of applications, including:
Industrial Plants
In industrial plants, thermal mass flow meters help plant operators keep the process gas flow running smoothly to avoid costly and inefficient production breaks. Industrial applications include:
- Aluminum and steel production
- Petrochemical industry
- Gas refineries
- Glass and ceramics
- Automotive
- Pharmaceutical
- Chemical industry
- Pulp and paper industry
- Power plants
- Textile mills
- Food and beverage
Wastewater Treatment and Biogas
In wastewater treatment plants, biogas, or methane, is the main by-product of the waste breakdown. Thermal mass flow meters are instrumental in controlling the release of methane to a collection unit. Additional applications include:
- Fermentation systems
- Agricultural waste digesters
- Cogeneration power systems
- Landfill gas recovery
Oil and Gas Industry
In the oil and gas industry, thermal mass flow meters are used to measure tank vent and flash gas during storage in addition to the following applications:
- Flares or combustors
- Green completions
- Refineries
- Gas compressors
- Vapor recovery units
- Gas allocation
- Environmental and emissions monitoring
Pure Gas Applications
Many different industrial customers use specialty gas for processes including:
- Welding shops and shield gas flow
- Medical gas
- Electronics
- Car manufacturing
Thermal Mass Flow Meter Benefits
There are many benefits to thermal mass flow meters, including:
Low Maintenance
Thermal flow meters do not have any moving parts. The compact design reduces the maintenance requirements and allows thermal mass flow meters to function in even the most demanding application environments, including those with saturated gas.
Measure Mass Flow
Thermal mass flow meters are designed to calculate the mass flow rather than the volumetric flow. This is beneficial in many applications because it removes the need for temperature or pressure correction. It also reduces the need for additional equipment.
Versatile
There are many different types of thermal mass flow meters. Many devices are available in both insertion and inline styles. Unlike some measurement tools, thermal mass flow meters can be used to measure gases in large pipes.
Accurate and Reliable
Thermal mass flow meters provide excellent accuracy and reliability across a wide range of applications and flow rates. The repeatability rates are also impressive at a margin of error of ±0.2% of full scale.
Since 2001, TechStar has been a one-stop-shop for quality instrumentation, analytical products, and automation services. TechStar also provides onsite field service support and hands-on training programs to meet your needs. For high quality thermal mass flow meters and a full range of flow solutions, visit TechStar today.