I just received my bottle of CYA 50 standard yesterday and I'm wondering how exact is the standard? I know that the CYA test results are probably the most subjective of all results but is the standard exactly 50. The reason I ask is I performed several tests with the 50 std. and consistently read 40.
The tests were performed indoors in a very well lit room under fluorescent bulbs. This is usually the where all my tests are performed.