Affecting the Selection
of a Cleanliness Measurement Method
There are a wide variety of cleanliness measurement methods
available to the manufacturer. To determine which method is right
for a given application many issues must be considered. Some of
the issues that affect the choice of method are:
- Type of contaminates to be monitored.
The method selected must be able to detect the contaminant of interest.
- Type of substrate being checked.
If the part is being inspected directly, then the method must be compatable with the material being measured, without causing any damage.
- Concentration range that must be measured.
The method must be able to detect the contaminants at the minimum and maximum concentration of interest.
- Accuracy and precision required
(i.e. how critical is it that the parts are cleaned to specifications?). Some methods provide gross estimates of contamination, even if they can detect contamination at very low levels, while others provide very precise concentration data for evaluation. The method selected must be appropriate for the application.
- Rate that measurements must be made.
Some systems can only be operated in a batch mode, while others have the ability to be automated for continuous operation. Also, the number of measurements that each type of method can complete per unit of time varies. The method
selected must be able to make analyses at the desired rate.
For a given cleaning process, it may be possible that more
than one method is required to measure all of the parameters of interest.
There are many measurement methods that can
be used to evaluate cleanliness in a manufacturing environment.
- Budgetary limitations.
The more precise and automated measurement systems tend to be very expensive. In addition, systems that accurately measure contamination directly on the part's surface tend to be
extremely costly. The cost/benefit of the measurement method must be evaluated.
Continue on to the types of measurement methods page of the Cleanliness Measurement Technology Review.
Return to the introduction of the Cleanliness Measurement Technology Review.
© 1999, Pacific Northwest Pollution Prevention Resource Center
phone: 206-352-2050, e-mail: email@example.com, web: www.pprc.org