Tool/software:
Please explain why the "Ultrasonic Sensing Subsystem Reference Design for Gas Flow Measurement" document on page 3 figure 2-2 recommends this design of flow pipe for gas measuring?
Your other gas meter documents recommend Trans-Axial and Reflected Flow Tube Designs for gas metering :
See Gas Meter Design Guide figure 2-2.
Here in our previous topic you recomended to use only Trans-Axial or Reflected Flow tube Designs for gas measuring.