Functional principle
CTM-EF 1000 series
en(us)
Page 21 / 52
BeWa CTM-EF 3509157c en-us 2018-10-18.docx
2018-10-18
Functional principle
The CTM-EF module is an extraction module for component sampling using
rinse extraction. This module is used in conjunction with the CTM-SC supply
module.
These components are rinsed off in a test liquid with a defined cleanliness.
At the end of the sampling process, the entire liquid with its particle load is
sucked via the membrane retainer. The rinsing liquid (now called the analysis
liquid) carrying the particulate soiling rinsed off the component, is sucked
through the analysis membrane by a vacuum via connection "R" and flows
back to the CTM-SC module.
The analysis membrane is then analyzed. The results provide information on
the type, size and mass of contamination.
Knowing what type of contamination is involved enables measures to be
taken to prevent it (improved filtration, transportation, storage, etc.).
Achievable negative control values
The achievable baseline (negative control value) readings strongly depend
on the ambient conditions and frequency of use. The following negative
control values can be achieved:
Ambience
Clean room
0.1 mg
Laboratory
0.1 mg
Separate sampling room
0.1 mg
Plant/factory shed
0.1 mg
Maximum particle size
Requisite effort
Cleansing time [h] after
shutdown
70 µm*
high
0.2
70 µm*
middle
0.2
70 µm*
low
0.2
* Applies to a maximum membrane load of 0.4 mg
