Icp-analysis inaccurate?

[Nht]

Hey guys. Just trying to see if you guys ever get inaccurate results from ICP tests. Got mine back and it’s saying that my salinity is a whipping 37.8 ppt. But my apex reads 34.3 ppt and I also have a Hannah salinity handheld checker that also reads in that ballpark at 35ppt.
Which should I trust as the true reading as it is quite a big variance between the Icp and what I’m reading at home. Please help so I can make the correction if need be

 

[clm65]

Have you tried testing refractometer calibration fluid with your meters?

 

[Nht]

Have you tried testing refractometer calibration fluid with your meters?

Yes I have. I just also calibrated both my apex salinity probe as well as my Hannah salinity probe last night and they both read the same at 34ppm. Is it possible that the icp salinity test is inaccurate?

 

[Nht]

^^