The oil samples needed to check the degree of contamination of hydraulic fluids must be taken in compliance with highly specific guidelines or the measurement results will not be representative for the system and not lend themselves to comparison with others.
Apart from absolute cleanliness for all devices coming into contact with the fluid to be sampled, these guidelines also stipulate the correct place for oil sampling, i.e. somewhere a representative distribution of solid particles is likely to be found. The valve required for removal purposes should be attached in the direction of the flow and without using any pipe between (Figure O 7).
Figure O 7: Arrangement for a sampling valve