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Boomer · 05-08-2008, 12:42 PM

OK JAK good but many from this company have been off -0-4 ppt when calibrated in RO/DI. Any hand-held refract should read 1.5 ppt to low when calibrated with RO/DI to a 35 ppt seawater salt mix. (3.5 or 1.0264). Meaning, if it reads 35 ppt with a RO/DI cal it will really be a 33.5 ppt seawater salt mix salinity and not the 35 ppt which the meter is reading. So, if all your meters are tested and good then one could tell the user to use just RO/DI and just have the refract read 36.5 which = 35 ppt NSW. Some of these meters are right on to NSW right out of the box when cal to NSW. This due to their poor quality control and poor optical properties. But, as long as we can correct them or they have been tested, such as yours, so one know where they are at, then they are fine to use. However, any hand-held refract is only good for a narrow range of NSW salinity. But all are fine within the range we use. It may have been that Huake just had a "bad batch" out. Hopefully it has been fixed.

05-08-2008, 12:42 PM	#53 (permalink)
Boomer Reef Sanctuary's Mr. Wizard Join Date: Nov 2003 Location: Duluth, Minnesota Posts: 2,206 View Gallery Karma Komment	Re: Refractometers OK JAK good but many from this company have been off -0-4 ppt when calibrated in RO/DI. Any hand-held refract should read 1.5 ppt to low when calibrated with RO/DI to a 35 ppt seawater salt mix. (3.5 or 1.0264). Meaning, if it reads 35 ppt with a RO/DI cal it will really be a 33.5 ppt seawater salt mix salinity and not the 35 ppt which the meter is reading. So, if all your meters are tested and good then one could tell the user to use just RO/DI and just have the refract read 36.5 which = 35 ppt NSW. Some of these meters are right on to NSW right out of the box when cal to NSW. This due to their poor quality control and poor optical properties. But, as long as we can correct them or they have been tested, such as yours, so one know where they are at, then they are fine to use. However, any hand-held refract is only good for a narrow range of NSW salinity. But all are fine within the range we use. It may have been that Huake just had a "bad batch" out. Hopefully it has been fixed. __________________ Boomer Want to Talk Chemistry ! The Reef Chemistry Forum Want to See More ! The Coral Realm If you See Me Running You Better Catch-Up An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.