Tektronix 434, Инструкция по эксплуатации

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Operating Instructions—434
3. Set the V O L T S /D IV s w itch and V a ria b le c o n tro l to
produce a d isp la y e x a c tly six d ivisio n s in a m p litu d e .
S u b s titu tin g the given values:
R isetim e = 6 X 1 (is
4. C enter th e d isp la y a b o u t th e center h o riz o n ta l line
w ith the v e rtic a l P O S IT IO N c o n tro l.
T he risetim e is 6 m icroseconds.
5. Set the T R IG G E R IN G c o n tro ls to o b ta in a stable
d isp la y.
6. Set th e T IM E /D IV sw itch to th e fastest sweep rate
th a t w ill d is p la y less th a n eig h t d ivisio n s between the 10%
and 90% p o in ts on the w a v e fo rm .
T im e D ifference Measurements
The c a lib ra te d sweep rate and dual-trace features o f th e
4 3 4 a llo w m easurem ent o f tim e d iffe re n c e betw een tw o
separate events. T o measure tim e d iffe re n c e use th e f o llo w ­
ing p ro ce d u re :
7. A d ju s t th e h o riz o n ta l P O S IT IO N c o n tro l to m ove the
10% p o in t o f th e w a ve fo rm to th e second v e rtica l lin e o f
th e gra ticu le (see Fig. 2-10).
8. Measure th e h o riz o n ta l distance betw een th e 10% and
90% p o in ts . Be sure th e V a ria b le T IM E /D IV c o n tro l is set
to C A L .
9. M u ltip ly th e distance measured in step 8 b y the
setting o f the T IM E /D IV s w itc h .
1. Set th e In p u t C o u p lin g sw itches to th e same p o s itio n ,
depending on th e ty p e o f c o u p lin g desired.
2. Set th e V e rtic a l M ode sw itch to e ith e r CHOP o r A L T .
In general, CHOP is m o re su ita b le fo r lo w -fre q u e n c y signals
and th e A L T p o s itio n is m ore suitable fo r h ig h -fre q u e n cy
signals. M ore in fo rm a tio n on d e te rm in in g th e m ode is given
u nder D ual-Trace O p e ra tio n in th is section.
3. Set th e T R IG G E R S O U R C E s w itch to CH 1.
E X A M P L E . A ssu m e th a t the h o riz o n ta l distance
between the 10% and 90% p o in ts is six divisions (see Fig.
2-10) and th e T IM E /D IV sw itch is set to 1 jus.
Using the tim e d u ra tio n 'fo rm u la to fin d risetim e:
T im e
D u ra tio n
(R isetim e)
h o riz o n ta l
distance
(divisions)
T IM E /D IV
s e ttin g
F ig . 2 -1 0 . M e a s u rin g ris e tim e .
4. C o n n ect the reference signal to th e CH 1 c o n n e c to r
and th e com parison signal to th e CH 2 c o n n e c to r. The
reference signal should precede th e co m p a riso n signal in
tim e . Use coaxial cables or probes w h ic h have equal tim e
delay to co n n e c t th e signals to th e in p u t co n n e cto rs.
5. I f the signals are o f o p p o site p o la rity , set the
IN V E R T s w itch o u t to in v e rt the Channel 2 d is p la y (signals
m ay be o f o p p o s ite p o la rity due to 18CT phase d iffe re n c e ;
if so, ta ke th is in to a cco u n t in th e fin a l c a lc u la tio n ).
6. Set th e V O L T S /D IV sw itches to produce fo u r or five
d iv is io n displays.
7. Set the T R IG G E R L E V E L c o n tro l fo r a stable
d is p la y .
8. I f possible, set the T IM E /D IV sw itch fo r a sweep rate
w h ic h shows three o r m ore d ivisio n s betw een th e tw o w ave­
fo rm s.
9. A d ju s t the v e rtic a l P O S IT IO N c o n tro ls to center each
w a ve fo rm (o r th e p o in ts on th e display betw een w h ic h the
m easurem ent is being made) in re la tio n to the center h o ri­
z o n ta l line.
2 -2 0