Has anyone had this problem . I have three INSTANT OCEAN specific gravity meters and one MILWAUKEE REFRACTOMETER .One INSTANT OCEAN is old and the other two are new . Testing the same water , the readings are as follows -- Old INSTANT OCEAN reads 1.022 . New INSTANT OCEAN , One reads 1.027 and the other goes straight to the top . No reading . The MILWAUKEE reads 1.024. Cannot get the same specific gravity reading. Any suggestions .