Gas Flow Totaliser

Gases are compressible, whose density changes with changes in Pressure and Temperature.

We have Gas Flow Totalisers which have in-built automatic computations of Density of the gas at flowing conditions.

Using advanced algorithms involving the physical and chemical properties of the flowing gas, these units compute the actual mass of the Gas flowing irrespective of whether the Gas has expanded or contracted due to temperature and pressure or has changed state (liquified or gasified).

Gas Flow Computer

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.

GFC-147

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.

The flow computer can easily be interfaced to scada or dcs systems as various options like analog retransmission and rs485-modbus outputs are available.

Salient features

Extensive database of gases

Compressed air
Ammonia
Iso-butane
N-butane
Co2
Co
Chlorine
Ethane
Ethylene
Helium
Hydrogen
Methane
Nitrogen
Oxygen
Propane
Propylene
Argon
LPG

Please do contact us even if your gas is not included in the above database.
multi-parameter display-

Volumetric flow
Mass flow
Gas pressure
Gas temperature
Gas density
Compressibility
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.

Two levels of passwords
One for the user and another for instrument configuration to avoid un-authorised tampering.
non-volatile memory to retain totalised flow, no batteries to change or fail.
isolated retransmission 4-20ma analog output , can be dedicated to represent any variable.
isolated rs485/rs232 modbus interface.

Graphical trends for flow.