Tom and all mathameticians,
I will stick with my original post, the machine will weigh this gas as it is designed to weigh R134a by the ounce or pound, if we used a scale and a 30lb bottle of R134a and serviced 30oz (1lb 14oz) of gas by weight then the job would also be correct. I just heard from an old hand this week that back in the 80's he use to turn the big bottle upside down and fill a graduated cylinder full of liquid up to the 30oz mark, turn the bottle valve completely closed then continue to allow the system to suck the graduated cylinder dry and you knew that you had serviced 30oz of R12 back in those days, the graduated cylinder was graduated to accept R12, not to accept water by volume nor by weight at the 30oz mark, just R12.
Just to bump on the retrofitted R12 to R134a you would not service the new R134a to the amount of R12 stated on the sticker or in the book, it will be in the 80% plus range, about 24oz (R134a) in a 30oz (R12) system, does this mean that R12 and R134a weigh the same, NO, I dont even know each weight by volume to be honest but I would not service by weight in a retrofitted system, 80% is a starting point and watching vent temps will be my ultimate goal when I cant get it any colder, yes this takes time, sometimes too much time as I am a little anal at times.
In this thread we are comparing apples to apples it seems, so lets just let the machine do its job according to the sticker of 30oz. kewl
Duane in Japan
Tachikawa Shi, Tokyo