MSP430FR6047: Not receiving clean downstream signal for clamp on water flow evaluation

Tool/software:

Hi

I currently have 1MHz set up in V configuration. Ands clamped on to a both copper and PEX pipes. 

I am using the MSP430FR6047 EVM with the following setup;

Transducers are set at 45 degrees with approximately 5.5cm apart.

Gain is set to -6.5dB but the measurement is receiver side anyway.

Please see attached plots that I am receiving for Copper pipe (CP) and PEX Pipes 

CPTIEVM2.pdfPEXTIEVM.pdfPEXTIEVM2.pdfCPTIEVM.pdf

Thanks Calex