Current position > News detail
『Electronic Mass Flow Meter Working Principle: Measuring True Mass Flow Without Corrections』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
Electronic Mass Flow Meter Working Principle: Measuring True Mass Flow Without Corrections
Quick Answer: An electronic mass flow meter measures the mass of gas or liquid moving through a pipe in kg/h or lb/min. Thermal mass flow meters do this without pressure or temperature compensation. Coriolis mass flow meters also read true mass flow directly. Silver Automation Instruments supplies both types for industrial sites in Southeast Asia, Oceania, Latin America, Africa, and the Middle East.
What Does an Electronic Mass Flow Meter Actually Measure?
Many flow meters measure velocity or volume. A turbine meter counts pulses. An electromagnetic flow meter measures voltage. These outputs change when gas density changes. To calculate mass flow from a volumetric meter you need pressure and temperature sensors. You need a flow computer. You need gas composition data. An electronic mass flow meter skips that step.
In practice, most engineers skip this part. Direct mass flow output saves time on a gas line. A thermal mass flow meter uses heat transfer to measure molecular flow. A Coriolis meter measures inertia. Both give the control system a true kg/h value. Electromagnetic flow meters also require a liquid conductivity above 5 µS/cm. A Coriolis mass flow meter has no such requirement.
How a Thermal Mass Flow Meter Works Without Corrections
Thermal mass flow meters are common for gas lines. They work with two sensing elements in contact with the gas stream. One element is heated. One element reads the gas temperature. In many designs the temperature sensor is a PT100 RTD. The heater and sensor sit in a 316L stainless steel probe or inline flow body.
Gas flows past the heated element. Moving molecules carry heat away. The temperature difference between the heated element and the reference element changes with mass flow. More mass flow means more cooling. The meter converts this temperature difference into a mass flow signal.
Because the sensor responds to gas molecules, it does not care if the gas is at 2 bar or 9 bar. It does not care if the gas is at 10 °C or 60 °C. It does not need a separate pressure transmitter for density correction. That is the main reason thermal mass flow meters are used for compressed air, nitrogen, biogas, and natural gas monitoring.
Why True Mass Flow Output Removes External Corrections
Volumetric flow meters report m3/h or L/min. Gas density changes with pressure and temperature. A fixed volume of gas at 1 bar contains less mass than the same volume at 8 bar. To get a true mass value you need to compensate the reading. This often adds cost and can add error.
A thermal mass flow meter outputs kg/h or lb/min directly. There is no need for a flow computer. There is no need to enter a density value from a lookup table. We have seen this on customer sites many times. A plant engineer wants to know how many kilograms of methane go to a boiler. The thermal mass flow meter shows that number on the display.
But there is a limit. Thermal mass flow meters work best on clean, dry gases. Liquids and slurries are be
Silver Instruments Electronic Mass Flow Meter Options
Silver Instruments supplies inline thermal mass flow meters from DN15 to DN100. Insertion types fit larger pipes from DN100 to DN300. Typical accuracy is 1.0 percent of reading from 0.5 m/s to 100 m/s. Repeatability is 0.2 percent of reading. The standard process temperature range is -20 °C to 120 °C. Pressure rating can go up to 16 bar depending on the flow body.
Output options include 4-20 mA HART, RS485 Modbus RTU, and pulse. Display options are local LCD or remote. ATEX Zone 1 or Zone 2 versions are available for gas lines in oil and gas sites. Suitable gases include compressed air, nitrogen, oxygen, carbon dioxide, natural gas, biogas, and argon.
A paint manufacturer in Vietnam recently used an inline thermal mass flow meter on a compressed air header at 7 bar. The meter replaced a vortex meter that needed pressure and temperature correction. The plant now gets a direct kg/h reading for air mass balance reports. A desalination plant in Saudi Arabia uses a thermal mass flow meter on carbon dioxide dosing lines.
FAQ: Five Questions Engineers Ask Before Ordering
Q: Can an electronic mass flow meter measure liquid?
A: Yes, but the type matters. A Coriolis mass flow meter measures liquid mass flow directly without density correction. A thermal mass flow meter is mainly for gases. Tell us the fluid and phase before ordering.
Q: Do I need straight run pipe for a thermal mass flow meter?
A: Inline types need less straight run than a vortex meter. We recommend 10D upstream and 5D downstream for most installations. Insertion probes need a stable flow profile. We can advise based on your pipe layout.
Q: What happens with moisture or oil mist in the gas?
A: Thermal sensors can drift if liquid droplets hit the probe. Use a filter or coalescer upstream. For dirty or wet gas, consider a Coriolis meter or contact our engineers.
Q: How do I know the flow range in kg/h?
A: Send us the pipe size, gas type, minimum and maximum flow, pressure in bar, and temperature in °C. We convert the velocity range to mass flow and quote a meter that matches.
Q: Can I get a version for hazardous areas?
A: Yes. Silver Instruments offers ATEX Zone 1 and Zone 2 versions. You will need to provide the gas group and temperature class for your site classification.
Get a Quote for a Mass Flow Meter Without Corrections
Send us your gas composition, pressure (bar), temperature (°C), pipe size (DN), and flow range (kg/h). We will recommend a thermal mass flow meter or Coriolis mass flow meter and respond with a quote. Contact Silver Instruments at Tel: +86-135-1213-1526, Whatsapp: 86-135-12131526, WeChat: +86 13512131526. The full range is on flow-meter.com.au.