A few technical terms are used for evaluating carpet cleaning products.
Soil Removal Efficacy
How well does a product remove soil. Certainly one of the most important criteria for cleaning.
This refers to wet cleaning products, and how well residual moisture is removed. Tests for this are straightforward when conducted on small carpet samples- a small section of carpet can be weighed before and after wet cleaning to see how much moisture is retained in the fibres.
How little is the texture of the carpet changed after cleaning?
An idea often not thought of – does a recently cleaned carpet attract dirt faster than an untreated piece of carpet.
A familiar but important idea – is the colour of the carpet unaffected by the cleaning process.
A carpet should be neither acidic nor alkaline. Either extreme will cause fibre corrosion.
Some cleaning substances give a brightness to cloth or fibre. This might be desirable for clean looking clothes, but it is a bad idea for the carpet as cleaned areas will look brighter that uncleaned areas, giving an uneven appearance.