Introduction: Explaining Frequency Bandwidth
Checking the Frequency Response Bandwidth makes sure you have set the range of measurement large enough to capture all the data, but not too large to affect its accuracy. After completing your first X-Direction taps, click on the radio button next to Freq. Response.
Step 1: Cutoff Wave
Here is an example of a measurement where one of the mode waves is cutoff a 5000 Hz. The Bandwidth for this tool needs to be increased to 10,000 Hz, the tool re-practiced and re-tapped.
Step 2: Bandwidth Example
Here is the Frequency Response Bandwidth. The default range is 5000 Hz and should be sufficient for most measurements. The other two choices are 2000 Hz and 10,000 Hz. What we like to say is don’t cut off any waves, but be sure you are not too far from shore. Check there are no large mode waves that are cutoff. This measurement looks fine. If the last wave was below 2000 Hz and then the line was flat at or near zero through 5000 Hz, then you should change the Bandwidth to 2000 Hz for maximum accuracy.
Step 3: Changing the Frequency Response Bandwidth - Step 1
To change the Frequency Response Bandwidth, click on the TXF Tab or hit F1 to return to the main TXF page.
Step 4: Changing the Frequency Response Bandwidth - Step 2
Click on the Setup Job button.
Step 5: Changing the Frequency Response Bandwidth - Step 3
Step 6: Changing the Frequency Response Bandwidth - Step 4
Use the pull down menu to the right of Measurement Bandwidth to change from the default 5 kHz (same as 5000 Hz) to 10 kHz (10,000 Hz) or 2 kHz (2000 Hz).
Click OK to save and return to the main screen. Click SAVE UPDATE to save changes.