HEWLETT PACKARD (HP) TM11-6625-1614-15
Service Manual

TM 11-6625-1614-15
Section III Paragraphs 3-28 to 3-34 PRF is the pulse repetition frequency in pulses per second (pps). Suppose, for example:
t

Model 410C 3-28. NEGATIVE PULSES. 3-29. In ( t2) and athe case of a 10 microsecond negative pulse pulse repetition frequency (PRF) of 1000 pps, tl would be 990 microseconds. Thus T / t1 would be
o

1 2

=

10 microseconds 990 microseconds

t

=

approximately 0, and from the graph it is seen that K is approximately 0. The expression would then reduce to

K = 0.55 PRF = 1000 pps To find K, assuming = 2 kilohms and tl=10micro3-30. It can be seen that in the case of negative pulses of short duration much smaller readings will be obtained for an equivalent positive pulse. As a result, large multiplying factors must be used and unless the pulse voltage is large, these measurements may be impractical. 3-31. MEASURING RESISTANCE (Figure 3-7). 3-32. Before making resistance measurements, power must be removed f rom the circuit to be tested. Also, make sure capacitors are discharged to eliminate any residual voltage. 3-33. MEASURING DC NANO-AMPERE CURRENT (Figure 3-8). 3-34. The Model 410C can be used to measure nanoampere leakage current in transistors and diodes. The three most sensitive DC voltage measurement ranges are used to measure DC nano-ampere currents.

seconds: o = 2 / 10° = 0.2. Location 0.2 on the X axis of the graph shown as Figure 3-6, and reading K where X and /Y axes intersect the unmarked curve. If R o tl were greater than 1, multiply the the ratio of X and Y axes by 10, and use the curve marked �R o / t1 and K each X10�. Solving the expression for the multiplying factor,

R /l

t

.

.

3-4