Morning all

As title, i'm trying to measure the superheat on 3 seperate systems that feed 1 common AHU. Howeve the install engineers did no put in any access ports at the evap outlet. I have access immediately before and after the TXV. The compressors are approx 20mtrs from evap with bends and each system has a suction accumulator.

What do you guys use as a rule of thumb given the pressure drop at the compressor suction service valve?