You should consider the different types of gas flow meters when buying them. There are several types of gas flow meters that you might encounter, including PD meters, differential pressures, velocity flow meter and mass flow meter. Let’s learn more about them.

What’s a Flow Meter?

A flow meter measures liquid flow and gas flow in a pipe. Let’s take a look at each of these four types.

1. Mass Flow

This meter can be used to determine the volume of gas or liquid flowing through it. There are two types of these units: the thermal and the coriolis. The coriolis type can measure the mass flow based on the deflection force applied to the fluid by vibrating tubes. These units provide a greater level of accuracy. They are also very expensive.

Thermal mass flow units are used to measure the flow of liquid or gas on the basis heat transfer through a heating element. These units are very accurate and easy to install.

2. 2. Velocity

This type of meter measures the flow rate of liquids or gases. Turbine flow meters, for example, measure volumetric flow by measuring fluid flow through a rotating free-spinning rotor. These units are extremely accurate, which is a plus. These meters are only suitable for dry grasses because they have many moving parts.

These meters use ultrasonic technology to determine plus transmit times differences. These meters are very accurate and can be more expensive than other types.

A shudder bar is included in the vortex type. This component causes liquid to flow in the direction indicated by the shedder bar, forming vortices at the bar’s backside.

3. Differential pressure meters

These meters determine flow by measuring pressure drop at obstructions in the flow path. These elements include flow nozzles and orifice plates, as well as venturi tubes and averaging pitot tube.

An orifice plate, a type differential pressure meter, is used to measure natural gas. The meter’s sole purpose is to measure volumetric flow. The equipment has some limitations, such as low flow sensitivity and limited turndown.

Basically, an averaging pitot tube is a type of differential-pressure meter designed for combustion air measurement. The tool has some limitations, such as low-flow sensitivity and turndown.

4. Positive Displacement Gas Flow Meters

This type of meter needs liquid to mechanically move the components and measure volumetric flow at running pressure and temperature. They are very efficient but require temperature and pressure to achieve mass flow.

These units have moving parts so the gas must be cleaned. A PD flow meter is another name for a PD meter. A type of PD meter is, for example, the diaphragm meter.