Why isn’t the result of 15.66 obtained? [Moisture Analyzers] [MS/MX/MF/ML]

1. Moisture bonded inside of the material as crystal water is theoretically 15.66%, however ambience has 10%RH ~ 90%RH moisture, which can adhere to the sample in a mechanical fashion. Ambient moisture that is 0.09% can adhere to most samples. Also, moisture and/or impurities left on a pan, accidental errors during measurement, or a combination of both can cause the result to vary between 15.0 and 16.0% in actual measurement.
2. If the difference between the actual result and 15.66 is large it is concluded that heating temperature may be too low. When Sodium Tartrate Dihydrate is tested, the accuracy of measurement of MS/MX/MF/ML should be set to MID of Standard Mode, with heating temperature of 160C; after pre-heating for 8 minutes, 5g of the sample should be placed on evenly on the pan.