The measurement of moisture in insulating oil may sound like a simple detection item, but in practical operation, there are many details that are easily overlooked - if not careful, the moisture in the environment can mix in, resulting in high accuracy and making incorrect judgments, which can actually be helpful. Sort out the complete process.

Step 1: Instrument preheating and reagent equilibrium

After turning on, the instrument will automatically enter the reagent equilibrium state, and the screen will display "Balancing reagents, please wait". This process involves the instrument automatically electrolyzing excess water in the electrolyte until the electrolyte reaches a stable anhydrous equilibrium state. Cannot skip, waiting time depends on the electrolyte state and environmental humidity, usually ranging from a few minutes to over ten minutes.

After the balance is completed, the screen prompts "sample measurement can be performed", and the sample can only be injected at this time.

Step 2: Pure water calibration (must be done before each use)

Extract 0.1 µ L of pure water using a 0.5 µ L sampler (imported SGE brand is recommended, domestic samplers have significant errors) and inject it into the electrolytic cell. The instrument measurement result should be within the range of "100 ± 3 µ g" (excluding injection error). Calibration should be performed 2-3 times, and the results should be stable within the error range before formal sample measurement can be carried out.

Step 3: Sample injection operation

Using a clean and dry sampler to extract insulation oil samples, the needle must be wiped with filter paper before injection - many people omit this step, but the residual moisture and reagents on the outer wall of the needle will affect the next experiment, making the instrument unable to reach equilibrium for a long time.

Insert the needle tip below the electrolyte level and inject the sample, without touching the bottle wall and electrode. After injection, the instrument automatically detects the sample and begins electrolytic measurement, with the screen displaying the accumulated water volume in real-time.

Step 4: Result Calculation

After the electrolysis is completed, enter the result interface and select the corresponding formula:

Known density and volume: automatically calculate ppm moisture content after input

Known volume: Calculate mg/L moisture content

Known quality: Calculate ppm moisture content

The results are automatically stored as historical records (up to 255 entries, including time stamps) and can be printed on paper.

Pay attention to injection volume control

The typical measurement range is 10 µ g to 100mg. The moisture content of insulating oil is usually in the range of 10-100ppm, and the sampling amount is generally 0.5-2mL. There is no need to take too much, as excessive injection will shorten the service life of the electrolyte.