HP 53131A, Operating Manual

Page: 114 / 196

Chapter 2 Operating Your Universal Counter
Using the LIMITS Menu Keys
2-38 Operating Guide
2
To Set and Use Automatic Limit Testing
Limits Testing Example 1—Flag and Stop Measuring
On Limits
For demonstration purposes, you want to first measure the ratio between
signals applied to channels 1 and 2 of the Counter. Next, you want to set
limits that would cause the Counter to flag (turn on the Limits
annunciator in the front-panel display) and stop making measurements if
these signals drift more than ±10% apart.
1 Connect input signals to channels 1 and 2 of the Counter, and set up the
Counter to measure the ratio between these signals. (Refer to the section
in this chapter titled “To Measure Frequency Ratio” if needed.)
Assume that the ratio measured between the two signals is 2.
If the drift is not to be larger than ±10%, then the upper limit should be
set to 2.2 and the lower limit to 1.8. Let’s set these values in the following
steps.
2 Press Uppr/Lower key until UPPR: is displayed.
UPPR: 0.000000 is displayed (0 is the default value).
3 Set UPPR to 2.2. (Refer to the section in Chapter 1 titled “To Set Limits of
Measurements” if needed.)
NOTE After you enter the value 2.2, BE SURE to press the Enter key to
complete the entry.
4 Press Uppr/Lower key until LOWR: is displayed.
LOWR: 0.000000 is displayed (0 is the default value).
5 Set LOWR to 1.8.
NOTE After you enter the value 1.8, BE SURE to press the Enter key to
complete the entry.