Throttling Turbo inlet valve confirms that gas load is coming from the chamber-side -> Connected LD and sprayed helium -> no response -> LD used is one that had been dedicated for view port testing in the labs and has older firmware that I am not familiar with -> can't find external cal-leak to confirm proper operation -> Did get a response however when O-ring joint (NW, KF) was sprayed at completion of testing -> Will leak test tomorrow (Wed) using "normal" equipment