MP Filtri ICM, User Manual

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56 Cycle Time and Flow Rate Considerations
17 Cycle Time and Flow Rate Considerations
The set Test Duration is the amount of time for which particle counts are accumu-
lated, before the test result is updated. The default of 120 seconds is likely to be
suitable for most applications. However it is possible to set other values.
A shorter time enables the unit to respond more quickly to variations in cleanliness.
This may be desired in order to reduce the product test time in a production line
situation.
A longer test time enables the unit to average out variations in cleanliness and
produce a more stable result. This is especially true for the larger particle sizes. In
clean systems there are very few of these, so a large amount of fluid needs to be
sampled in order to count a statistically significant number.
Another factor is the flow rate. This can be traded off with cycle time, since a higher
flow allows the same amount of fluid to be sampled in a shorter time.
"Very Clean’’ Systems – Longer test times / higher flows needed.
"Normal’’ or "Dirty’’ Systems – Shorter test times or lower flows are acceptable.
This relationship is shown in Figure 17.1.
22
This means >20 particles counted as per ISO 4406:1999