Working principle of a Gas Flow Computer
It is known that real gases expand with rising temperature, and compress with rising pressure and vice versa.
This means that the same mass of gas will have different volumes at different sets of temperature and pressure conditions.
In other words, the density of such gases is heavily dependent on the pressure and temperature. Therefore just volumetric flow measurement is just not suitable for such gases. The real parameter of interest is the Mass Flow.
Alternatively, the actual volumetric flow for gases is often represented as "normalised" or "corrected" to standard pressure and temperature conditions.
Mostly measured in nm3/hr or scfm , this is flow of the volume of gas, had it been flowing at "standard" or "normal" temperature and pressure conditions ( stp / ntp)
The above mentioned change in gas density is a complex mathematical function of temperature, pressure and the physical and chemical properties of the gas.
The perfect solution to your gas flow measurement needs
sometimes referred to as efm ( electronic flow meter) or mass flow computer ( mfm) , our gas flow computer gfc-147 has an internal database of physical properties of most commonly used industrial gases. It measures gas pressure and temperature , and uses extremely complex algorithms for calculations of gas density & compressibility. . . All in real time.
It also uses algorithms confirming to international standards like iso 5167 to compute flow from orifice plates, venturis, flow nozzles, pitot tubes etc. And corrects for factors like reynolds number when the flow is computed.
So, it can be connected to any of these standard flow measuring systems such as:
- Vortex flowmeter
- Orifice plate, dpt
- Pitot tube, venturi,'verabar' etc.
Extensive database of gases
- Compressed air
- Volumetric flow
- Mass flow
- Gas pressure
- Gas temperature
- Gas density
- Mass total
- Normalised flow
- Normalised total
Preset temperature or pressure values
The values of temperature and pressure can be programmed in case on-line signals are not available or a transmitter failure.