Liquid Flow Meters
The ability to measure the flow of liquids using liquid flow meters is a critical need in many industries. In some cases the inability to take accurate flow measurements can cause serious negative results. The majority of liquid flow measurement instruments determine the flow rate by inferentially measuring the liquid’s velocity or change in kinetic energy. The velocity is determined by the pressure differential that is forcing the liquid through a pipe or conduit. The average velocity is an indication of the flow rate. The liquid’s viscosity and density, and the friction of the liquid in contact with the pipe are other factors that can affect the flow rate of the liquid. Positive-displacement flow meters can be used to find the direct measurements of liquid flowing. These types of units divide the liquid into specific increments as its moving, then the total flow equals an accumulation of the measured increments. Those measured increments can be counted mechanically or electronically to get the total flow measurement.
Flow measurement is the quantification of bulk fluid movement. There are a variety of ways to measure flow. For example, positive-displacement flow meters accumulate a fixed volume of fluid and count how many times the volume is filled to measure flow. Another method to measure flow relies on forces produced by the liquid as it is flowing across a known constriction. The flow may be measured by calculating the velocity of fluid over a known area.
Liquid flow can be measured in volumetric or mass flow rates. If the materials density is known the measurements can be converted between one another. Liquids are measured in various units depending on the application and industry. Some examples are gallons per minute, liters per second, or bushels per minute. When referring to river flows cubic meters per second (cumecs), or acre-feet per day are used.