Preamplifiers for Panaflow

It isn't clear if this is a case of
- 'new installation, isn't working yet' or
- 'was working OK, but isn't now' or
- 'it never worked and I was told to get it running'.

I'm not familiar with GE's ultrasonic flowmeter but other from brand other ultrasonic flow meters experience shows that there are some things to look at

1) Most ultrasonic meters require a minimum (pipeline) gas pressure to produce a gas density sufficient to 'carry' the ultrasonic signal. Does your minimum pressure comply with the requirement?

2) The interface between the ultrasonic transducer and the pipe requires a clean smooth surface with an ultrasonic transmissive gel compound. Field reports at recent attempts to substitute an elastomer (rubber-like) show questionable performance. What condition is transducer/pipe interface?

3) If the flow meter was installed outdoors, the coaxial cable connectors might have allow moisture into the cables (also a problem in washdown environments). That's a serious no-no. What condition is the transducer cable/connectors in?

4) Is the alignment/spacing of the transducers correct for the pipe size? An insulation installer or pipefitter hasn't moved them out of the way?

5) Is there a setup parameter for expected 'speed of sound' through the gas? If that's incorrect, the meter might consider its reading out-of-range. Same gas as before? Same pressure as before? Did it ever work?

Dear Iris.

- was working OK, but isn't now

1)&4) All the USM sizing done by our principle in US, and no worry regarding that.Since the meter already sent for calibration before installation.

3) We need to check back all the coaxial cable connector installed inside the Junction box and the cable inside flexible fire retardant conduit. Now the meter at Vietnam offshore.... :I

5) We got the copy for the configuration, recheck every time at site and no changing at all. Previously it working for several gas testing, now all the gas testing triggers the SS error.

2) Cannot tell. Need to check first the transducer physically.

Can the CO2 and wet gas profile causing the errors?? The sound speed absorption by the gas.

CO2?

I've done ultrasonic level measurement for years and the rule has been: No CO2 blanket atmospheres. The ultrasonic level signal doesn't get down and back through CO2 at whatever frequency the level transducers used.

I am not familiar with CO2 for ultrasonic gas flow measurement (all my experience is liquids). Frequencies could be different, the whole measurent could be technology could be (and probably is) different, but I have to ask, when this system worked previously was CO2 the medium in the pipe? Or some other medium?

You say, "several gas testing", which could mean measurements on different media other than CO2.

Was this application reviewed by GE specifically for CO2?