A few weeks ago I purchased a new micron gauge since my Supco VG quite working right. This time I picked up a YJ 69075 and it's taught me that I really never owned a good micron gauge before now. From 760,000 to 1 scale and it's quite impressive. I have even seen how moisture is pulled through your rubber hoses but it sure does. Trying to pull down a split system with a 2" suction and 5/8 liquid line of about 140 feet. After 4 or 5 hours I'm still rising back up to 15,000 microns from a low of maybe 4000. Finally flared some 1/4 tubing and used it in place of my regular manifold and brought it all down to 455. So far I've been able to dry out 3 of these 15ton systems with one more to go. 2 pumps running together with just the 1/4 tubing on each pump, one on the high and one on the low side.
Anyone looking to purchase a good micron gauge should take a serious look at this one. Not overly expensive either.