Tektronix 494A Water Dispenser User Manual


 
a
o
o
o
a
t
o
o
o
o
I
t
o
I
o
I
a
o
I
t
o
a
o
o
o
O
o
o
a
o
o
O
t
a
o
o
O
O
I
O
o
o
I
I
Sectfon
6
-
494A/494Ap
Servicc
Vot.
1
4.
Nothing
capabl€
of
generating
or
hotding
a static
charge
should
be allowed
on
the
work
station
sur-
face.
5.. Keep
the
cornponent
leads
shortEd
together
whenever
possible.
9
Pick
up
components
by
the
body,
never
by
the
leads.
7.
Do
not
slide
the components
over
any
surface.
8.
Avoid
handling
components
in
areas
that
hav€
a
floor
or work-surface
covering
capabfe
of
generating
a static
charge.
9.
UsE a soldering
iron
that
ls
connected
to
€arth
ground.
10.
Use only
special
anti-static
suction
type
or
wick
type
desoldering
tools.
Voltage
Equlvalent
for Levels:
1-100to500V
a-500V
2
-
200to
500
v
5
-
400
to 600
v
3-250V
6-600to800V
a
Voltage
discharged from
a
100
pF
capacitor
through
a
resistance
of
100{).
MAINTENANCE
INTRODUCTION
This section
describes procedures
fol
reducing
and
pr€venting
instrum€nt.
malfunction,
tioubleshootint
methods,
correctave
malntenance,
and
procedures
for
recalibrating
those
assembties
that
normally
do
not
require
routine
calibration.
Removing
the
Instrument
trom
its
Cabinet
T-o
prepare
the standard
instrument
for
maintenance
or adiustment,
perform
the
following
steps-
1.
S€t
the
instrument
on
lts
facs
or
front
panel.
2. Loosen
the
four
screws
in
th€ feet.
3. Pull
the
cover
up and
off.
4. Place
the
instrument
on
the
work
bench
and
reconnect
the
power
cord.
Static-Sensitive
Componentg
This
instrument
contains
electrical
components
that
9an
be
damaged
by static
discharge.
See
iabte
6_1
for
the relative
susceptibitity
of
varioui
classes
of
semicon-
ductors.
Static
voltages
of
1
kV
to
30 kV
can
occur
in
unprotected
environments.
Static
discharge
can
damage
any
semicon_
ductor
component
in
this
instrumint.
Observe
the following
precautions
to
avoid
damage:
1. Minimize
handling
of
static-sensitive
com-
ponents.
2. Transport
and
store
static-sensitive
components
or assembli€s
in
their original
containers,
on
metal-
ized
or
conductive
foam,
Label
packages
that
con-
tains static-s
en sitive
as
sE
mbl
ie
s or
com,-ponents.
3. Discharge
body
static
voltage
by
wearing
a
grounded
wrist
strap
while
handling
these
com_
ponents.
Statie-sensitive
assemblies
or
com-
ponents
should
be
handted
and
serviced
only
at
static free
work
stations
by
qualified
service
person_
nel.
Tabte
6-1
RELATIVE
SUSCEPTIBILITY
TO
STATIC DISCHARGE
DAMAGE
fa400to
1000
V
(estl
8-900V
9-1200V
MOS
or
CMOS microcircuits
or
discretes,
or linear
microcircuits
with
TTL
(L€ast
Sensitive)
6-1