Samples preparation Sample Clauses

Samples preparation. Sample preparation is a keystone before conducting laboratory determination of properties: insufficient care or unsuitable methods can degrade or even completely wrong laboratory determination. For example, handling samples with moisten or greased bare hands can contaminate their surface, which can lead in non-­‐characteristic deterioration of the sample. A) Handling of samples Clean gloves are required for handling samples both to avoid contamination from the operator’s hands to the sample or from it in the case of toxic or hazardous materials. Typical gloves are either latex, PVC or cotton, and should be disposable to reduce contamination from sample to sample or to/from the environment of the operators. Respiratory masks may be required if the sample has stray fiber content, such as typical insulating materials. Masks following the EN 149:2009 should be chosen. Masks with FPP2 grade is usually acceptable, unless nano-­‐particles may be present where FPP3 masks should be used or better such as positive pressure respiratory systems. Disposable masks with valve should be chosen for long period of uses (more than one hour), or better half-­‐face masks.