Here is another one. I just got a new sh 35n superheat subcooling guage. Hooked it up to a a/c with a 88 outdoor temp and 56 wet bulb suction pressure 72 and the new guage read 14.9 superheat. suction line temp was 54. tthe liquid line pressure was 250. But I could not get a 20degree drop from the incoming air to out going. the out going was 54.4 and the in was 70.8.