60
Programming
4.1.1.7 Pneumatic Signal/Noise Ratio
The larger the PSN Ratio, which is the Cal Value divided by the
Comp Value, the more repeatable the test will be. The PSN Ratio
can be in the range of 0.2 to 0.25 if +/- 10% test repeatability is
sufficient.
So for pressure decay tests, the following rules are strongly
recommended:
Comp Value
≥
0
PSN Ratio (Cal / Comp)
≥
0.2
Cal Value
≥
0.05% of full scale of the sensor
For PSN Ratio, the larger the better. Longer test times typically
yield a larger PSN Ratio.
If the Comp Value is set to zero, the PSN Ratio will display as
99999.
