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Sect.ll
P:ige
4
U
the
desired
trigger
poinr oI the input
wavefor
m is
rising
(goiflg
in
a
positive
d]rcction),
set the TRIG-
CER SLOPE
switch to
+.
IJ
the
desircd
trigger
point
of the input waveform
is faliing
(negative
going).
the
TRIGGER SLOPE
should be set
to -.
To set the TRIGGER
LEVEL VOLI
S
contr.ols
rt is
necessary
to l(low
the
voltage
levels of
tie
input
wave.
The TRIGGER
LEVEL
VOLTS
control is then set
to
the
voltage value
desired. Any direct current
cr)tn-
ponent
of the signal must also
be
considered
when
setting these controls.
EXAMPLE:
Figure 2-2
It is
desired to measure the tin]e
betwee:l fr;rr1t.i
A
and
L^
oI Figure 2-2.
Since
this is
a
si|f'l(,
rijfjr.lj
th3 SEP.
-COM.
srvitch shoutd
t,c in the COl,,t.
p0-
siliolr.
Since
rll"
l,oltrgc ll[
poilt
A is risi]tS.
s{)l
the
strrt
TRICiGER
SLOP!
s..{it(
tr
t{)
,
and
thr,
s,....r.-,
TIiICCEIt LEVEL VOLTS (,olltrol
r-q
+
20. prrint C
is
neg:rtive going anil the stoi)
TltlccEll
SLOtIE
ii
ttch
sir()ulj
l)(,sel
to
-.
lhe
srr)p
TRIGCillft
Lit\.EL VOi
:S
sh()ukl bc
set
to
*lj5V.
Set
the
'
l,jit UNII
sv..rii
i,
I0
th(,desi|cd
Lrnit.
It
will
ire
notcd
thirt
if
li1r,
start
i
ITICCER
,
t,\
Fr
VOLTS c()r)trol
were
Set
to
r35
rt:itea.l
o, :ll
tj,e
time frorrr points
B
io
C would tte n]easur r.,ii.
A
j.
,
i{
the sto!- TIiIC,GER
SL()PE sv/itcir
,rere
r.hlii,rrr,ri
i
,
-
Islnud
,)l -.
il)c lrmp
lr..t\y,.en
Ix.il,ts
A.rnd
p
,
,.,1,
bc
n|asured
In
nteasur.ing
th(,tilr)e
l)etwe.!t
A
.
l
I
C
thc
start
TRIGGEn
I.EVEL VOLTS c,)rtr1.i
,
,rti
be
sct irt
t)oint D
(-l
5V)
r\hiclr -.,iill
gi.,.1,
ihr.
.rr
,,
time.
p",19.111 _ll!,91
ln
i){tth
p(.ri(rd
ltrrrl
ti|]tc
itlterval
nie:LS!j,
,-..la,,rts.
1
nlav
l'.,(l('sirable lo
har.e
ir count
in
S{}lire
unit
rirl
thar
o)
ln terms of some other
f
rerltrr,r..i,.
t
r-,
.
stiu[e.
llre ln,rtocl
of
e
2
cV(
le w!l,e
r:l
,riil
l.x-
llr
lr,;
r
,
oI
some
.tht:r'
1!!r,'e.
Sitl, :i600 c\.,-,leS.
ftiis
iti,.,i.sr
tll
li,tir,.,l
lhe
l'.vo
J
r'q
t.:,,....i
..\'.r,,'t
.vr,u
lll
re ltJ,)!
t,
Tll., procedure l(rt usii! tl)e
(
xLarnal ir:,,ilt
is
,j
:
Iollo!vs:
a.
Set
the
FUNCI'ION SELECTOR
s\vit.ir
Lo
ihc l,
PE
RIOD
A\IERAGE. PERICD. r'lr.TIME LNTEit-
VAL position.
h
Sel
the
TIME tiNIT's\r,itch to EXT.
and,,,rnn(,r.l
thrr
extcrnal ifequcncy
tr)
the
EXT. te.nt,niti.
c.
Connect
the source
to
be
[]easured to the INPUT
termintl or
the START
and
STOP
terminals
(Time Interval) whichever lrnction
is
being
used.
d.
The displayed count
is
obtained
in units of
the
exlernal signal applied to the
instrument.
When
the
TIME
1JNIT
switch
is
in the EXT. position,
the
decimal points are not
ilLuminated.
Manual
Girte
a.
Set
the I'UIiCTION SELECTOR switch
to
MAN-
UAL GATE
and
the TIME UNIT switch to
the
EXT.
position.
b.
Set
the MANUAL GATE
switch to the closed
po_
sitien.
Connect
the source to
be
measured to
the
EX
1'.
term
i
na
l.
..
Io start
the
coLrnt.
throw the switch to
Ule OPEN
i{siticrn.
At
thr: end
oI the desired elapsed
time
chN'ute
the
switch brck to the
closed
position.
Read
thc Liisplayeri
count.
push
thc
RESET button
and the
irs,t1'.,r,"na
iSj|ci!d!: to
.jount
again. The
iimc,
duritlg
,,\'j
th
tl!.r rt:rto
is open,
mllit
l)e
ureasxred bv
some
o,
ri(
F
,.ul:,t
1,, ..1
rlrp lnsttrtnt(.nt
iir
ti..rs
(,per'!tiorr tire
MANUAL GATE switch actdaliv
uperrs;,rrr:l cio-qes
lite:'31e:lt
the
instant the switch is
operate{i arld nlrl
at
i}ie Dcxl
timing pulse
as
in
a1l
of
'
\,\
r)t
i-,,"
ic,us
.jr.:r-iilrori-c,
The MANL'AL
OATE
Switch
l.1a\i
I\.(rl)en(,rl iitrd
Lirjs(}ri
:!E,ften
aS
d.lsil.ed
:rnd no
!i:j,,rijn!: will
orcui.
llesf,lljng
Dtust
be d()ne
lr)anualh,
l'
ih^
iiESI--l
i
"
.j,.
.rn.l
rniv
1,r.
d6nr irt
.itrv
tinte.
2"3
ACCURACY
I
r-r'quellr-y
Meastlt
f
olants
I'l:e La:;ir'
rOunt(
r
.i(,..iraC:,
iS
deterllrined
bV
LwO
.
lc,is. (r.,, []{ r.)r
rs
.,
.rltbillt\
or thr,
l00kccr7s_
l.il
s1:Itcl.,r,1
it, tir.)
ti1,r",t)ise.
which
is l0
pai:ts
per
uiilr'r.
or
.
{)(;1
pr,r.r
lrir lc!-
wce
k. A
sci:oirC
facir,t,
is
th.
inhct{trt crt.,.:
r){
,
i
,
ount
piesent
in all
coun-
it,la
,,:
Lllls
t,,-J.r.'.
l'ltiji
rt.i'rr
is
dur,.
to
pirasing
berw.,en
'r,'
Ir:"il
.,1'.::. ,1d:
r.,,r:Csrrr r.I,..ir,rrIi
cale ard
',"
pr.
Ln,rt
irss
lrr.o rql' lh,...iLrr t,.
till
courrtors.
ilr. ,ltrlrt
jri Figur.. -l-3
sholvs
the
errr)rs
to
tle
l,xrr;.(
toii 1([.
lrequeli
i
{,r peri(Xi
]easu re]-Itertts.
For
'.i-lrrFle.
ii
i
ireque .., itI
10
kc:
is
L(ting measuted
ru:lh
a
10
scroad
g,rt.'tinre,
tiere
n.ill
be
a
torai ol
100,000
r:lr.rrrr:; An
errot
of
+1
couirt
is
.001 pereent
iii irui;lcv-
li
20
kc
is
tneasired
for
1Lt
seconds.
a
iot:!i of
20t1,000
coulr.s,
+1
cc,Lrnt
is
.
00C5
percent.
Howe\.r,r-,
the
t(curacv (.i01
percent)
oi the
cr-vstat
sllldl.r
I
also must
be
takc,D
into consideration.
The o'"'era.ll irccirrrrcl.
iOr frequency measurements
ihcn is
as
lollows:
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