Clamp On Ultrasonic Gas Flow Meters

Although industrial gas flow meters are widely utilised for liquid and water applications, it has long been accepted that clamp on gas flowmeter technology could not be applied to mass gas flow measurement primarily due to fundamental theoretical measurement limits. In fact only 4.9 x10–7 percent of the transmitted sound energy is received by traditional ultrasonic transducers. However, advances in clamp on gas flow measurement technology and processing have meant that despite lower acoustic impedance levels and higher attenuation levels in most gases, a clamp on gas flow meter can now measure transit times in gases where signal-to-noise ratios are extremely low. It is now possible to measure natural gassteamcompressed airhydrogencompressed air and many more using clamp on flow meters.

Clamp on Gas Meter measuring NitrogenA clamp on ultrasonic gas flow meter produces signals that are five to ten times more powerful than those of traditional ultrasonic transducers. The new clamp on transducers produce clean, coded signals with very minimal background noise. The result is that a clamp on gas flow meter can now provide optimum performance even with low-density gas applications. Today, our ultrasonic clamp-on gas flowmeters such as the Panametrics CTF878 and the Panametrics GC868 can measure the flow of any gas and then calculate mass flow using a pressure transmitter connected to the analogue input. Such clamp on flowmeters are extremely useful in almost all gas flow applications: 

Gases that can be measured with ultrasonic clamp-on flowmeters include:
Compressed Air Hydrogen Oxygen
Nitrogen Steam Natural Gas
Propane Butane Corrosive Gases
Erosive Gases High Purity Gases Sterile Gases
Toxic Gases Inert Gases Compressed Air

As there are no modifications to the pipe, installation costs are dramatically reduced. Indeed, one instrument can be used to survey many flow measurement points in one day. The meter can be installed on any unlined pipe of metal or plastic construction from 0.75-24.0 inches in diameter with operating temperatures of -40° to 300° F.

Clamp on Gas Flowmeter TheoryAn illustration of the Panametrics PT878GC ultrasonic clamp-on gas flowmeter:

If you'd like to consult with one of our flow specialists to help you choose the ultrasonic flow measurement solution that best suits your application, please feel free to contact us.