or imperial) per minute, liters per second, bushels per minute or, when describing river flows, cumecs (cubic meters per second) or acre-feet per day. Gas mass flow rate can be directly measured, independent of pressure and temperature effects, with thermal mass flowmeters, Coriolis mass flowmeters, or mass flow controllers.įor liquids, various units are used depending upon the application and industry, but might include gallons (U.S. References will be made to "actual" flow rate through a meter and "standard" or "base" flow rate through a meter with units such as acm/h (actual cubic meters per hour), sm 3/sec (standard cubic meters per second), kscm/h (thousand standard cubic meters per hour), LFM (linear feet per minute), or MMSCFD (million standard cubic feet per day). A volume of gas under one set of pressure and temperature conditions is not equivalent to the same gas under different conditions. Gases are compressible and change volume when placed under pressure, are heated or are cooled.
![flow meter flow meter](https://img.alicdn.com/imgextra/i1/6000000007894/O1CN01HFdwDo28BV6Aiv4uv_!!6000000007894-0-tbvideo.jpg)
In engineering contexts, the volumetric flow rate is usually given the symbol Q. Energy flow rate is usually derived from mass or volumetric flow rate by the use of a flow computer. The energy flow rate is the volumetric flow rate multiplied by the energy content per unit volume or mass flow rate multiplied by the energy content per unit mass. When gases or liquids are transferred for their energy content, as in the sale of natural gas, the flow rate may also be expressed in terms of energy flow, such as gigajoule per hour or BTU per day. This is not the case for gases, the densities of which depend greatly upon pressure, temperature and to a lesser extent, composition. The density of a liquid is almost independent of conditions.
![flow meter flow meter](https://img.directindustry.com/images_di/photo-g/5551-3579071.jpg)
These measurements are related by the material's density. 11.3 Ultrasonic flowmeters (Doppler, transit time)īoth gas and liquid flow can be measured in physical quantities of kind volumetric or mass flow rates, with units such as liters per second or kilograms per second, respectively.
![flow meter flow meter](https://image.made-in-china.com/2f0j00VZwQqkuofycY/Class-B-Rust-Proof-Drinking-Water-Flow-Meter-for-Potable-Water.jpg)