Karl Fischer Coulometric Analyzer Calibration Specification

1. Subject Content and Scope of Application This specification specifies the technical requirements and calibration procedures for calibration of the DL37 Karl Fischer Coulometric Analyzer from METTLER TOLEDO.

2. Calibration conditions 2.1 Main technical specifications Measurable range: The water content in the test sample is 10 μg to 100 mg water.

Sensitivity was measured: 0.1 μg water.

Accuracy: (Reproducibility) The coefficient of variation of 1 mg of water measured in methanol was 0.3%.

Background (drift): Automatic compensation. The background level is always shown on the display.

2.2 Calibration conditions Ambient temperature: 20±10°C

Relative humidity: 40% to 80%

3, calibration method 3.1 until the instrument background (drift) is stable, and shows "Stable" (highly accurate measurement ready), only to start with pure distilled water correction.

3.2 Use a needle with a rubber cap to weigh distilled water (0.007-0.01g), rapidly inject into the titration cell where the <START> key has been pressed, and press the <SIZE> key. The display of the moisture analyzer displays “Lot?” and press <ENTER>. Press the key to confirm that the weight of the last mentioned sample appears on the display. Press the <-> key and enter the weight of the sample just stated on the balance. Press the <ENTER> key to confirm. “Wt2?” is displayed. Press ENTER key again to display the pre-titration countdown. When the titration reaction is over, the system will automatically alarm and display the result and print it out.

4. Calibration results processing and calibration cycle 4.1 Calibration results Processing calibration must be repeated 2 or 3 times. The measured value ≤ 3% indicates that the instrument is working properly. If the measured value is greater than 3%, check whether the electrolytic cell is sealed and used on the electrolytic cell. Whether the silica gel is discolored and water-absorbed, whether the electrolyte fails, and whether the electrode is contaminated. The silicone should be replaced and the electrode cleaned on a regular basis.

4.2 Qualified instruments shall be affixed by the technical team to the “certificate of approval” and shall be used. Unqualified instruments shall be marked “disabled” by the technical team and stored in isolation. The original records of the calibration shall be completed and archived in a timely manner.

4.3 This calibration work requires 2 times a month.

5, the calibration record