• When sampling, a sample is drawn from the process and taken into a sample container.
  • For liquids, this container consists of a bottle with a threaded, open-top cap.
  • Between the bottle and cap a self-sealing diaphragm (septum) is placed.
  • The septum is of such material that when pulled from the needles, it reseals.
Unit of Measure

  • The function of the cap is to keep the septum in place.
  • The type of cap to be used depends on the bottle used for sampling.
  • Each of our bottles is specifically fitted with a matching cap and septum, so that spillage or leakage can be avoided.
  • As a general rule it is advised to use Dopak containers, caps and septa specifically for use with a Dopak sampling system.
  • When samples are stored for future reference a double cap can be used for complete sealing after the sample has been taken.
  • An additional septum can then be used between the under and extra overcap.
  • Note that under-caps are different from standard caps; therefore over-caps cannot be used with standard caps.
  • Under- and over-caps are supplied as a set.