Experimental results are summarized in table, where t is the time of immersion in the cleansing liquid
and Q is the coefficient of visualization of indicating patterns, which determines the flaw detectability.
The tests aimed at estimating parameters of operations of excessive penetrant removal lead to the following conclusions. The flaw detectability decreases considerably at longer time of sample immersion in
the cleansing liquid. Figure 2 shows images of a tested surface for t = 0.5 min and t = 1.5 min. If the
immersion time is increased by as little as 1.5 min (from 0.5 to 2.0 min), the flaw detectability drops by
a factor of almost six. If the immersion time is increased further, detection of flaws on the tested surface
is practically impossible