Water Content Analysis

Method Karl Fischer Volumetric Autotitrator
Standards ASTM D 1744

What is it used for?

To quantify the amount of water present in a given oil sample.


How does it work?

A known weight of an oil sample is placed in a reaction cell with a portion of solvent using an auto-pipette and an analytical balance.


An iodine-based reagent is then added step-wise to this until all traces of water are neutralised.


The quantity of reagent needed to counteract the water in the oil is then used against the weight of oil added to determine the quantity of water in the sample.


What do the results tell us?

How much water is present within a given sample, whether it’s free, dissolved or emulsified.


This is key, as water is possibly the single most destructive contaminant commonly found in used (or sometimes unused) oil.


There are many paths for water to get into oil, which may include:


Poor storage

Environment (product ingress, clean-downs, humidity, etc.)


Coolant contamination

Leaking seals and filler caps

Assuming that using sight glasses to drain off free water is sufficient, leaving emulsified and dissolved water behind.


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