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FIGURE 9-4. Relationship of estimated- and actual-frequency ranges and frequency
warning flags
The actual range is equal in size or larger than the estimated range. If you wish to know the
actual boundaries, in DVW Toolbox, click on View > Advanced. Two new columns, Actual Low
Frequency and Actual High Frequency, appear on the main window.
If using DVW Toolbox is not practical, you can calculate the actual boundaries. Calculate the
actual-frequency range using boundary resolution value in the fourth column of
as a reference. For example, if the data logger scan interval is set to 500 ms, the VWIRE 305
sample rate is 20 Hz and its boundary resolution is 47.68 Hz. If you estimate the low-frequency
boundary at 150 Hz, the nearest multiple of 47.68 Hz that is less than the estimate is 143.04 Hz (3
• 47.68 Hz). Enter 143.04 into low-frequency boundary in DVW Toolbox or
LowFreq
in CRBasic.
Likewise, if you estimate the high-frequency boundary at 500 Hz, the nearest multiple of 47.68
Hz that is more than the estimate is 476.80 (10 • 47.68 Hz). Enter 476.80 into high-frequency
boundary in DVW Toolbox or
LowFreq
in the CRBasic program.
Matching estimated and actual frequency ranges
Minimize the difference between the estimated-frequency range and the actual-frequency range
by entering the actual frequency values as the low-frequency boundary and high-frequency
boundary. However, there are benefits to not having the estimated-frequency range match the
actual-frequency range. The VWIRE 305 issues warning flags if the measured frequency falls in
the gaps between the two ranges.
VWIRE 305
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