Hello everyone, Hope you can guide me to the correct tread or help me here. I've been using a gretag densitometer and it gives readings similar to: 1.45 m 1.35 c 1.1 y 1.8 k With those readings i get pretty much the result we need but i just got a used x-rite 408 and gives very diferent readings: 1.75 m 1.7 c 1.24 y 1.3 k I tried the quick calibration and did not change much. I then tried tu buy a reference card but i don't know whether this unit is polarized or non-polarized so i ended up with two main questions: 1 Is there a way i can tell whether if it is polarized or non? 2 is this a common fault to densitometers and may be fixed by the long calibration or it might need service or repair? Any help appreciated Moe