Other Parts Discussed in Thread: EVM430-FR6043,
I am currently attempting to get a proper signal for various different gases. I understand that, to account for the sound speed of the gas being used, I need to change the ADC capture such that: ADC Start Capture Time = (Ultrasonic Path Length/Speed of Sound) – 40us. (In my case, my path length is ~160mm).
With a gas such as Argon, I am able to get a clear enough signal such that my ToF matches well with the theoretical sound speed of Argon. Below are my settings for the Argon measurement.
When switching the gas to something with a greater sound speed (Methane, Helium, Hydrogen, etc), I am unable to properly optimize my settings to get a good signal. For example, below is the ADC capture I am getting when using Hydrogen instead of Argon.
I am unsure of what additional parameters (such as "Start PPG Count" or "Turn on ADC Count") need to be changed to capture a proper signal. I know my connections are fine, as I am able to switch back to Argon or Air and get a clean signal again.