Daily Maintenance Of Moisture Analyzer
First, there are 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 service life of the instrument.
2. The room temperature is below 5 degrees or above 40 degrees.
3. Do not install in direct sunlight and high humidity places.
4. Do not install in places where the power supply is unstable. It is recommended to use an electronic voltage stabilizer.
Second, there are precautions for the use of moisture analyzer.
1. Since the titration reagent is easy to absorb 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. In the titration process, the stirring should be sufficient and uniform.
4. When injecting samples, prevent the syringe head from being contaminated by the outside and affecting the measurement results, such as the operator's exhalation and contamination when wiping the syringe head.
5. The Karl Fischer method produces sulfuric acid in the reaction to measure 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 entrance of the reagent bottle to prevent the reagent from absorbing moisture in the air, reducing the titer, and causing serious measurement errors.
7. During the titration process, false endpoints sometimes appear, that is, reaching the endpoint early, resulting in low measurement results.
Third, there are precautions for maintenance of moisture analyzer.
1. Most instruments use polarized double platinum electrodes to measure voltage. After a period of use, certain Karl Fischer reagents and samples will invalidate the electrode response and end point recognition will be delayed, causing the end point color to change to brown instead of yellow. At this time, the electrode must be cleaned. When cleaning, the electrode is generally placed in an ultrasonic cleaning tank with deionized water or ethanol for a few minutes; or placed in chromic acid for 60 seconds, and then cleaned with deionized water or ethanol (dry before use).
2. Under normal circumstances, the drift value of the instrument is a few microliters per minute. If the drift value becomes larger, the tightness of the instrument must be checked or molecular sieve regeneration must be considered. During the regeneration process, place the molecular sieve in a drying oven at 160-300°C for at least 24 hours. The molecular sieve installed on the waste bottle contains water and sulfur dioxide, so it must be washed with distilled water before it can be regenerated.
3. Clean the burette with ethanol solution. Do not expose the burette to temperatures above 40°C. Do not put organic solvents in the connected o-rings and rubber pads.
4. There is a self-check system inside the instrument. If the instrument fails, it will give a corresponding fault signal. The user can understand the cause of the failure by viewing the instrument manual, and eliminate the failure in a targeted manner.
5. The 50g moisture analyzer must be placed in a dry and clean environment and be kept by a dedicated person; if it is not used for a long time, all reagents in the instrument must be drawn out, and all tubes must be cleaned and air-dried.