Basic knowledge points of moisture analyzer
Characteristics of micro-moisture analyzer
Small size and light weight; It can display the titration process in Chinese, and can input and output in Chinese and English.
Color LCD display, graphical interface, simple and convenient operation, easy to master.
The LCD screen directly displays dew point, micro water (ppm), ambient temperature, ambient humidity, time and date, battery power, etc.
Touch screen input, you can independently complete the complicated detection process with just a click.
Preparation before use
1. Treatment of electrolytic cell: Specific operation: Shake the electrolytic cell a few times to make the water on the inner wall of the tank bottle fully absorbed by the electrolyte, then put the electrolytic cell into the holder, turn on the stirring switch, adjust the stirring speed to make the liquid surface form a small vortex, insert the measuring electrode plug and the electrolytic electrode plug into the corresponding socket of the main machine, and make them contact well, then turn on the electrolytic switch.
Note: In the state of iodine excess, the green lights of the measurement signal indicator and the electrolysis signal indicator are all turned off, only one red light is lit, and the digital display does not count.
2. Adjust the balance of electrolyte: Specific operation: If the electrolytic cell is still in the state of deep iodine excess, press the start button and inject it into the electrolytic cell below the liquid level several times through the hole in the middle of the sampling cock, and observe the color change of electrolyte at any time until the electrolyte turns pale yellow, the green light of the measuring signal lamp and the electrolytic signal lamp indicates, and the counter starts counting. When counting stops, stop stirring, pick up the electrolytic cell and shake it a few times, so that the water on the inner wall of the tank bottle can be absorbed again, and calibration can be carried out after the end point alarm.
3. Calibration: Specific operation: After the electrolyte is stable, extract a small amount of distilled water with a micro sampler, wipe the needle with filter paper, press the start button, and inject it below the liquid level. The instrument starts counting, reaches the end point, displays the water quantity, and calibrates it for 2~3 times continuously, and the counting values are all within the required range, which shows that the instrument is accurate.
Note: When calibrated with distilled water (100%), the allowable error is within 10%.
FREQUENTLY ASKED QUESTIONS
1. The color of anolyte is not bright yellow, but between brown and dark yellow.
Reason: The electrolyte color of the moisture analyzer is too dark, which is the decrease of the response ability of the electrode to the electrolyte.
Solution: the double platinum needle electrode can be cleaned with paper towels to remove the adsorbents on the surface; Check whether the measuring electrode is normally connected; The measuring electrode may fail.
2. Pre-titrate fresh anolyte, and the drift is too high.
Cause: There is residual moisture in the titration system.
Solution: You can replace the molecular sieve and silica gel in the drying tube, and check whether the electrode interface and plug interface of the titration stand are tight; Silicone grease can be properly coated on some loose interfaces.
3. What is the reason for the high drift during standby titration?
Reason: The water in the cathode cell permeates into the anode cell through the diaphragm.
Solution 1: The electrolyte of anode cell can be replaced; Adding a small amount of one-component volumetric Calfee reagent to the cathode electrolytic cell for drying; Keep the liquid level of the anode liquid higher than the liquid level in the cathode cell.
Solution 2: Clean the titration cup effectively and remove the continuous side effects caused by the samples left in the last test; Check the tightness of titration system.
4. The drift value of the sample after titration is very high.
Cause: The test sample had a side reaction with the anolyte, and the reaction produced water.
Solution 1: Replace other kinds of anolyte or other sample pretreatment methods.
Solution 2: Let some volatiles in the sample react with Calfee Hugh's reagent.
Solution 3: Improve the sample pretreatment method.
