UV-Visible Spectrophotometer

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prabhakarthota's picture
UV-Visible Spectrophotometer

How can we check  performance of quartz cuvettes , we are presently checking transmitance at 200,220 and 240 nm,as part of our monthly instrument calibration procedure. what should be the ideal transmitance value to say that the cuvette is performing satisfactorily (we are using minimum 80% transmitance as specification) . what is the standard industrial practice ? where can we get relevant references?

Dr. Analytical
Dr. Analytical's picture
The 80% value is a reasonable

The 80% value is a reasonable test, and is similar to what the manufacturers use for their specifications.  The only reason the cells would fail the test is if they are contaminated or damaged.

The supplier of your cells should be able to provide specifications.  Check with the various standards organizations also: ISO, ASTM, etc.

The importance of this measurement depends on the type of instrument that you are using.  If you have a single beam instrument and are using the same cell for blank and sample, then any changes in the cell are removed when you measure the blank.  If you have a double beam instrument, then the quality of the cells is very important, and they should be matched as closely as possible.