HP (Hewlett-Packard) E42 ユーザーズマニュアル

3–18. To set up a time interval measurement, the marker outputs may be monitored on an

interval of interest. The GATE/MARKER OUT is high during the time interval being measured.

3–19. In T.I. 

 and T.I. AVG 

 with the rear panel ARM switch OFF, the counter is armed

by the run down of the SAMPLE RATE control. With the rear panel ARM switch ON, T.I. 

and T.I. AVG 

 are armed by an event at the C input. For T.I. AVG 

 only one arming

signal is required per average measurement (i.e., the counter doesn’t need to be armed prior
to each individual time interval in the time interval measurement).

3-21. For ratio measurements, the 5328A has wide bandwidth, good sensitivity, and complete
signal conditioning of the Channel A, B, and C input amplifiers.

3–22. Two ratio functions are available: B/A and C/A. The ratio of the frequency at B (or C)
to the frequency at A is measured for N counts of A where N is selected by the RESOLUTION

switch. The resolution of the measurement improves with increasing N and is given by 1 part

in B/A x N (or C/A x N). Since the range of A is 0-10 MHz while B is 0-100 MHz, the lower
frequency is normally applied to the A input although there is no restriction that this be the

case (i.e., ratios less than 1 may be measured). If B/A is greater than 1, the measurement reso-

lution is better than switching the inputs for a ratio <1, provided the value of N remains the same.

3-6 and 3-7.