The pressure's going the wrong way. Is this really an appropriate testing environment? Or is this suit pressurised to rho.g.(h+3m)?
The pressure has got to be above ambient or he couldn't breath. It's not a constant volume, one atmosphere suit.
It it an appropriate test environment? With suitable ballast, quite possibly, especially for testing 1/6th gravity EVA procedures. It's not the suit that is being tested here, but movement under simulated partial gravity.