Division 4.2.1.3 Specific requirements Original text. Later amendments are not shown. 4.2.1.3.1Sample probe 4.2.1.3.2Particle transfer tube (PTT) 4.2.1.3.3Secondary dilution 4.2.1.3.4Sample pump and flow meter 4.2.1.3.5Filter and filter holder ← Division 4.2.1.2.11 Division 4.2.1.3 Division 4.2.1.3.1 →