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Encyclopedia > Gas meter
A residential gas meter of the usual diaphragm style
A residential gas meter of the usual diaphragm style

A gas meter is used to measure the flow of fuel gases such as natural gas and propane. Gas meters are usually used at every residence and commercial building that consumes fuel gas supplied by a gas utility. Image File history File links Download high resolution version (1500x1500, 895 KB) A residential gas meter. ... Image File history File links Download high resolution version (1500x1500, 895 KB) A residential gas meter. ... Fuel gas can refer to any of several gases burned to produce thermal energy. ... Many stoves use natural gas. ... Propane is a three-carbon alkane, normally a gas, but compressible to a liquid with inexpensive containers. ... In economics, utility is a measure of the happiness or satisfaction gained consuming good and services. ...


Three different designs of gas meters are in common use, depending on the total volume of gas to be measured.

Contents


Diaphragm meters

These are the most common type seen in most installations and almost all residential installations. Within the meter are two chambers formed by movable diaphragms. With the gas flow directed by valves, the two chambers fill from the gas source and empty into the gas load, alternating their roles so that gas delivery to the load is essentially continuous. As the diaphragms expand and contract, levers connected to cranks convert the linear motion of the diaphragms into rotary motion which then drives the counter mechanism. In mechanics, a diaphragm is a sheet of a semi-flexible material, anchored at its periphery, and most often round in shape. ... A valve is a device that regulates the flow of fluids (either gases, fluidised solids, slurries or liquids) by opening, closing, or partially obstructing various passageways. ... Look up crank in Wiktionary, the free dictionary. ... In general, a counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred often in relationship to a clock signal. ...


These are positive displacement meters.


Rotary meters

This is also a positive displacement meter but uses what is essentially a Roots Blower rather than a pair of diaphragms. In this way, the meter is capable of handling both higher volumes and much higher pressures than a diaphragm meter. To provide a leakproof seal, the indicating mechanism is sometimes magnetically coupled to the measuring rotors through the pressure case of the meter. In physics, magnetism is one of the phenomena by which materials exert an attractive or repulsive force on other materials. ...


Turbine meters

This type of meter uses a turbine contained within the gas pipe. This is not a positive displacement mechanism. These meters allow the highest gas flow, but they have the lowest rangability. The positive displacement meters can accurately measure (at ±1%) gas flows over a very wide range from their maximum rated flow rate all the way down to 1/100 of that flow rate or less, turbine meters are only accurate down to between 1/12 and 1/33 of their maximum rating (depending on the absolute pressure of the gas). Pressure (symbol: p or P) is the measure of the force that acts on a unit area. ...


Calorific value

The measurement provided by positive displacement meters is an absolute measurement of the gas volume flowing through the meter; the measurement provided by a turbine meter is an approximate measurement of gas volume. Unfortunately, gas volume (whether absolute or approximate) isn't the measurement actually desired by the gas utility. The measurement actually desired is the thermal energy contained in the fuel gas (which is proportional to the number of molecules of fuel gas delivered to the customer), this is known as the calorific value. In chemistry, a molecule is an aggregate of at least two atoms in a definite arrangement held together by special forces. ... Heating value (or calorific value) is used to define the amount of heat released during the combustion of a fuel or food. ...


The calorific value of natural gas can be obtained using a process gas chromatograph, which measures the amount of each constituent of the gas, namely: Many stoves use natural gas. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ...

Additionally, to convert from volume to thermal energy, the pressure and temperature of the gas must be taken into consideration. Pressure is generally not a problem; the meter is simply installed immediately downstream of a pressure regulator and is calibrated to read accurately at that pressure. Varying temperature can not be handled as easily, but some meters are designed with built-in temperature compensation to keep them reasonably accurate over their designed temperature range. The simplest hydrocarbon, methane, is a gas with a chemical formula of CH4. ... Ethane is a chemical compound with chemical formula C2H6. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... This article focuses on water as it is experienced in everyday life. ... Pressure (symbol: p) is the force per unit area applied on a surface in a direction perpendicular to that surface. ... Temperature is also the name of a song by Sean Paul. ... Pressure (symbol: p) is the force per unit area applied on a surface in a direction perpendicular to that surface. ...

The indicator on the above meter
The indicator on the above meter

Image File history File links Download high resolution version (2048x1536, 559 KB) The indicator on a residential gas meter. ... Image File history File links Download high resolution version (2048x1536, 559 KB) The indicator on a residential gas meter. ...

Indicating devices

All three types of gas meters can be obtained with a wide variety of indicators. The most common are indicators that use multiple clock hands or digital readouts similar to an odometer, but remote readouts of various types are also becoming popular. A modern non-digital odometer A Smiths speedometer from the 1920s showing odometer and trip meter An odometer is a device used for indicating distance traveled by an automobile or other vehicle. ...


Clamp On Gas Flow Meters

Another type of gas flow meter is the clamp on gas flow meter which can be used to measure gas in any size of pipe without modification. Such devices are based on two types of technology: (1) time of flight or transit time; and (2) cross correlation. Both technologies involve transducers that are simply clamped on to the pipe and programmed with the pipe size and schedule and can be used to calculate mass flow. Such meteres can be used to measure almost any dry gas including natural gas, nitrogen, compressed air and also steam.


  Results from FactBites:
 
Gas Meters (1804 words)
Originally gas meters did not "know" the temperature of the gas flowing through them, so it was required to keep them in a consistent temperature range to keep the gas measurement consistent/accurate.
Gas is typically colder than the air temperature in the summer and warmer than the air temperature during the winter.
Our natural gas utility clients are also able to extend the value of the information Itron systems provide to deliver new rates and services, improve distribution system planning and maintenance, and to improve the accuracy of forecasting and nominations to more precisely manage supply and demand in today's increasingly volatile natural gas market.
fuel flow meters (3441 words)
The ultrasonic time-of-flight gas flow meter is based on measurement of contra propagating ultrasonic pulses, in which the transit time of the sonic signal is measured along one or more diagonal paths in both the upstream and downstream directions.
The flow of gas causes the time for the pulse traveling in the downstream direction to be shorter than for the upstream direction, and this time difference is a measure for the rate of the gas flow, see Fig.
Generally, ultrasonic flare gas meters utilize transducers are mounted with the front centre point flush with the inner pipe wall for all pipe sizes from 6" to 72", see Fig.
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