Latest Gas Clamp On Ultrasonic Flow Meter for mass flow measurement at low pressure

February 03, 2006 (PRLEAP.COM) Business News
RS Hydro has recently won a contract to supply the latest Panametrics CTF878 Correlation Tag flowmeter for clamp-on gas flow measurement in the Middle East used for a natural gas production facility. The CTF is capable of mass flow measurement in metal pipes at all pressures including ambient. Whereas other clamp on ultrasonic flow meters use transit-time technology, correlation tag technology is able to measure flows at lower gas densities than the transit-time equivalent. Being a clamp-on device, it is not restricted by pipe size or composition.
The CTF878 flowmeter uses four clamp on ultrasonic transducers arranged as two pairs. Each pair acts as a transmitter and receiver. The transmitters send an ultrasonic signal in a continuous wave mode through the fluid to the receivers, forming an interrogation path. The continuous wave signal is modulated by turbulence and local density variations characteristic of moving gas, producing a unique turbulence signature. The flow velocity is then determined from time and distance measurements.
The CTF878 measures gas flow non-invasively in pipes from six to 30 inches in diameter, over the range of 3.5 to 150 feet per second (1.1 to 46 meters per second). The flow meter is designed for applications such as natural gas transmission and distribution, compressed air, fuel gases, corrosive or toxic gases, high-purity gases, and air separation gases.
Correlation tag technology is effective in gas applications because of the compressibility of gases, which helps create the distortion of the ultrasonic signal needed for the flow measurement technique. The CTF878 gives customers the ability to handle a significantly wider range of clamp-on gas flow applications than was possible before. The main advantage of the CTF878 over transit time flow meters is its ability to measure flows at ambient or low pressures.
RS Hydro specialises in portable and fixed installation non contact ultrasonic flow measurement for all liquids and gases.