ONE. Precautions for installation of moisture analyzer:
1. The instrument should not be installed in a room with corrosive gas, which will corrode the circuit of the instrument and shorten the life of the instrument.
2. Where the room temperature is below 5 degrees or above 40 degrees.
3. Do not install it in a place with high sunlight and high humidity.
4. Do not install in places where the power supply is unstable. It is recommended to use electronic voltage regulators.
TWO. Matters needing attention in the use of moisture analyzer:
1. Since the titration reagent easily absorbs water, the tightness of the burette and titration cell is required.
2. The size of the reagent titer should be determined according to the water content of the test solution.
3. During the titration, the stirring should be full and even.
4. When injecting the sample, it is necessary to prevent the syringe head from being polluted by the outside world and affecting the measurement results, such as the exhalation of the operator and the contamination when wiping the syringe head.
5. The Karl Fischer method will generate sulfuric acid in the reaction of measuring water. When its concentration is higher than 0.05%, a reverse reaction may occur, affecting the measurement result.
6. A dryer should be installed at the inlet of the reagent bottle to prevent the reagent from absorbing moisture in the air and reducing the titer to cause serious measurement errors.
7. During the titration process, sometimes the phenomenon of false end point occurs, that is, the end point is reached in advance, resulting in a low measurement result.
THREE. Matters needing attention for maintenance of moisture analyzer:
1. Most instruments use a polarized double platinum electrode to measure voltage. After a period of use, certain Karl Fischer reagents and samples will invalidate the electrode response and the end point identification will be delayed, so that the end point color becomes brown instead of yellow. At this time, the electrode must be cleaned. When cleaning, generally put the electrode into an ultrasonic cleaning tank with deionized water or ethanol for several minutes; or put it in chromic acid for 60s, and then clean with deionized water or ethanol (dry before use).
2. In general, the drift value of the instrument is a few microliters per minute (referring to the amount of Karl Fischer reagent consumed per unit time in order to keep the titration cell dry: this reagent is used to titrate the titration cell on the one hand The water, on the other hand, compensates for the consumption of iodine caused by slow side reactions). If the drift value becomes larger, you must check the tightness of the instrument or consider regenerating the molecular sieve. During regeneration, the molecular sieve is placed in a drying furnace at 160-300°C for at least 24 hours. The molecular sieve installed on the waste water bottle contains water and sulfur dioxide, so it must be washed with distilled water before regeneration.
3. Wash the burette with ethanol solution. Do not place the burette at a temperature above 40°C. Do not put organic solvents in the connecting O-rings and rubber pads.
4. There is a self-inspection system inside the instrument. If the instrument fails, it will give a corresponding failure signal. The user can understand the cause of the fault by referring to the instrument manual and eliminate it in a targeted manner.
5. 50g Moisture Analyzer must be placed in a dry and clean environment, and arrange for someone to keep it; if it is not used for a long time, all the reagents in the instrument must be drawn out, and all the tubes must be cleaned and air-dried.