The sonic device I refer to is made by TIF Industries. Any large A/C wholesale supply can get it for you. As good as the VOV may sound the stock set-up is very adequate assuming the rest of the system is functioning properly. On my cars I just set the suction pressure at 34 degrees and a high side below 150 psi for R-12. David Teitelbaum vin 10757 --- In dmcnews@xxxx, "Walter Coe" <Whalt@xxxx> wrote: > David T, > > > 2) Using a sonic device to detect supercooled droplets in the suction > > line. > > I never knew that such a device existed; though, I have heard of a similar > device that detects vapor bubbles. Can you recommend a source for learning > more about the sonic devices? >