The Karl Fischer moisture titrator is an instrument used to determine moisture using the Karl Fischer titration method, which uses the permanent stop method to determine the endpoint. When both I2 and I - are present in the solution, the above reaction occurs on two electrodes, where I2 is reduced on one electrode and I - is oxidized on the other electrode, resulting in a current passing through the solution. If there is only I - and no I2 in the solution, then there is no current passing through the solution. When there is a trace amount of Karl Fischer reagent present in the solution at the endpoint of titration, both I - and I2 are present simultaneously. At this time, the solution conducts electricity, and the ammeter pointer deflects, indicating that the endpoint has been reached. Calculate the moisture content based on the amount of iodine consumed in the titration reaction.

Common faults and troubleshooting methods:

Power supply and startup failure:

Unable to power on: Check if the power plug is loose, if the power cord is damaged, replace the blown fuse (such as 0.5A specification), and if it still does not work, repair the power module.

Display abnormality: Restart the instrument and check the ambient temperature and humidity (recommended 20-25 ℃, humidity<60%). Preheat for 30 minutes after long-term storage.

Measurement result deviation:

Poor repeatability:

Use standard water samples (such as 10mg/g methanol solution) to calibrate the instrument, and the recovery rate should be between 97% and 103%.

Control the environmental humidity (<60%) to avoid electrolyte moisture absorption.

Drift value too high:

Replace the drying tube molecular sieve (regenerated or replaced when the silica gel turns pink).

Pre titrate until the drift value is less than 20 μ L/min before measuring the sample.