Notes on the use of Karlsham's moisture meter 1. Most instruments use a polarized double platinum electrode to measure voltage. After a period of use, certain Karl Fischer reagents and samples will fail the electrode response, the endpoint recognition will be delayed, and the endpoint color will turn brown instead of yellow. At this point the electrode must be cleaned. When cleaning, the electrode is usually placed in an ultrasonic cleaning bath with deionized water or ethanol for several minutes, or in chromic ACID for 60 seconds, and then rinsed with deionized water or ethanol (dry before use).

2. Under normal circumstances, the drift value of the instrument is a few microliters per minute (this refers to the amount of Karl Fischer reagent consumed per unit time to keep the titration cell dry; this reagent is used to titrate the titration cell on the one hand. The moisture, on the other hand, compensates for the iodine consumption caused by slow side reactions.) If the drift value becomes large, you must check the instrument's tightness or consider regenerating the molecular sieve. During regeneration, the molecular sieves are dried in a drying oven at 160-300° C. for at least 24 h. For molecular sieves installed on waste water bottles, because they contain water and sulfur dioxide, they must be cleaned with distilled water before regeneration.

3. The burette is cleaned with an ethanol solution. Do not place the burette above 40°C. The connecting O-rings and rubber pads must not be placed in organic solvents.

4, the instrument has a self-test system, if the instrument fails, it will give the corresponding fault signal. As long as the user compares the instrument instructions, they can understand the cause of the failure and eliminate it in a targeted manner.

5, the instrument must be placed in a dry and clean environment, and arrangements for safekeeping; if you do not use for a long time, you must extract all the reagents in the instrument, and all the tubes are cleaned and air dried.