I asked this question in another forum.... I am not agreeing with another tech on this..This is for asystemwith a piston. I find my target superheat.Lets just say 8 degrees.I get my low side press. at the port at the cond. I check line temp at the oulet of the evap. Now he is checking it at the suction line at the cond., I say that is going to overcarge because by checking it there would make your whole suction line part of your evap. Now if you were going to check a txv you would get your line temp. at the bulb location which is at the evap. outlet. Both txv and pistons are metering devices and are mesuring refrig. through the evap. not the evap. and the suction line. Before this starts up i know its important to check it at the cond. also and look for around 20 deg. there for proper cooling of the comp. Some input and exactly how you all check this would be greatly appreciated.