Tektronix 208 User manual

TEKTRONIX
( R )
208
STORAGE
MONITOR
WITH
OPTIONS
APRI
1975
SERVICE
INSTRUCTION
MANUAL
Tekt ronix ,
Inc.
P.O.
Box
500
Beaverton , Oregon
97077
Serial Num ber
070-1923-00 First Print ing MARCH 1975

H
WARRANTY
All TEKTRONIX inst rum ent s are warranted against
defective
m at erials and
workm anshi p
for
one year
.
Any quest ions wit h respect to the warranty should
be taken up wit h your TEKTRONIX Field Engineer or
representative
.
All
requests for
repairs and
replacem ent part s
should be directed to the TEKTRONIX Field Office
or representative in your area . This will assure you
the fast est possible service . Please include the
inst rum ent Type Num ber or Part Num ber and Serial
Num ber wit h all
requests for part s
or
service
.
Specifications and price change privileges reserved .
Copyright  1975 by Tekt ronix , Inc. , Beaverton ,
Oregon . Print ed in the Unit ed States of Am erica . All
right s
reserved .
Contents of this
publicat ion
m ay
not
be reproduced in any form wit hout perm ission of
Tekt ronix ,
Inc.
U.S.A. and foreign TEKTRONIX product s covered
by U.S. and
foreign patent s and / or
patent s pendi ng
.
TEKTRONIX is a regist ered t radem ark of Tekt ronix ,
Inc.

208
Service
TABLE
OF
CONTENTS
PAGE
vi
List of Illust rations
List
of
Tables
vii
SECTION 1
SAFETY
INFORMATION
AND
SPECIFICATIONS
1-1
Safety
Inform at ion
Power
Source
Safety
Specifications
1-1
1-2
SECTION
2
OPERATING
INFORMATION
Controls , Connect ors , and Indicators
2-1
Front
Panel
2-1
Rear Panel
2-2
2-3
Operating Power Inform at ion
Low Batt ery Indicator
Batt ery
Charging
2-3
2-4
2-4
2-5
Batt ery Replacem ent
AC Adapt er Connect ion
Operating
Tem perat ure
Hum idit y
2-5
2-5
SECTION
3
THEORY OF OPERATION
Sim pli fied
Block
Diagram
3-1
Power
Supply
3-1
3-1
3-1
3-1
ECG /
PULSE Am plifi ers and
Vertical
Am plifi er
Sweep
Generator
and
Horizont al
Am plifi er
Blanking Am plifi er
Erase , Storage , and Swit ching
Circuit
Description
ECG /
PULSE
and Audio
3-1
3-2
3-2
Circuit
Funct ions
3-2
3-3
3-3
ECG
and
Pulse
Am plifi ers
Float ing
Supply Oscillat or
Float ing Input Am plifi er
Current to Voltage Converter
ECG /
PULSE Swit ch
3-3
3-4
3-4
a
i

208
Operators
TABLE OF
CONTENTS
(
CONT
.
)
PAGE
SECTION
3
( CONT . )
AC - Coupled Am plifi er
3-4
Display
Am plifi er
3-4
Trace
Recovery
3-5
Audio Circuit
3-5
Audio Input Am plifi er
3-5
3-6
Free
-
Running
Multivibrat or
Audio
Output
Driver
3-6
Vertical and Horizont al Am plifi ers and Sweep
3-6
Circuit
Funct ions 3-6
Vertical
Am plifi er
3-6
Horizont al Am plifi er
3-6
Sweep
Generator
3-6
Erase
, Storage
,
and
Swit ching
3-7
Circuit Funct ions
3-7
Erase
and
Storage
3-7
Swit ching
3-7
3-10
3-10
3-11
Power Supplies and Crt
Circuit
Funct ions
Power
Supply
Prim ary
Oscillat or
Prim ary
Regulator
and
Low Voltage
Shutdown
Low Voltage Rect ifier and Regulator
High Voltage
Multiplier
3-11
3-11
3-11
3-11
3-11
Low Batt ery
Detect or
Run Current Am plifi er
3-11
Crt
Circuit ry
3-12
SECTION 4
MAINTENANCE
Prevent ive
Maintenance
4-1
Routine
Schedule
4-1
Operator
Inform at ion
4-1
4-1
External Cleaning
Inspect ion
4-1
ii
@

208
Service
TABLE
OF
CONTENTS (
CONT . )
PAGE
SECTION 4
(
CONT .
)
Service
Inform at ion
4-1
Cleaning
4-2
Calibration
4-2
4-2 Leakage Current
Check
Correct ive Maintenance
4-3
Tekt ronix Field
Service
4-3
4-3 Keeping a Service
Record
Soldering
Inform at ion
Obt aining Replacem ent Parts
4-3
4-3
Standard
Parts
4-3
Special
Parts 4-3
Ordering
Parts
4-3
Recalibrat ion
After Repair
4-3
Com ponent
Replacem ent
4-3
Tools
Required
4-5
Batt ery
Rem oval
4-5
Batt ery Replacem ent
4-5
Cabinet Top
Rem oval
4-5
4-5
4-5
4-5
Cabinet
Bottom
Rem oval
Cabinet
Replacem ent
Interconnecting Cable and Term inal Connect or
Replacem ent
ECG
Board
Rem oval
ECG
Board
Replacem ent
Storage
Board
Rem oval
Storage Board
Replacem ent
4-6
4-6
4-6
4-6
Audio
Board
Rem oval 4-6
Audio
Board
Replacem ent
4-6
4-6
4-7
Front Panel or Im plosion Shield Rem oval
Front Panel
or
Im plosion Shield
Replacem ent
Cent ral Interconnected Group Rem oval
Cent ral
Interconnected
Group Replacem ent
4-7
4-7
Main
Board Rem oval
4-8
Main
Board
Replacem ent
4-8
@
iii

208 Service
TABLE OF CONTENTS ( CONT . )
PAGE
SECTION
4
( CONT . )
Fuse
Replacem ent
4-8
4-8
Push Butt on Swit ch
Rem oval (
DISPLAY Push
Butt on Swit ches Only )
Push Butt on
Swit ch
Replacem ent
4-10
Light
Em it ting
Diode (
LED )
Rem oval
4-10
4-11
4-11
4-11
LED
Replacem ent
Circuit
Board Term inal
Pin and
Term inal Pin
Socket
Replacem ent
Sem iconduct or
Replacem ent
Troubleshooting
Troubleshooting Equipm ent
Troubleshooting
Aids
Diagram s
4-12
4-12
4-12
4-12
Circuit Boards
4-12
4-12
Sem iconduct or Lead Configurat ion
Troubleshooting
Procedure
Inst rum ent
Repackaging
4-12
4-16
SECTION 5
CALIBRATION
Calibration Interval
5-1
Test Equipm ent Required
5-1
Special
Test
Accessories
5-1
5-1
5-1
Equipm ent
Required
Index to
Calibration
Procedure
Prelim inary Test Setup
Calibration
Procedure
5-2
5-3
SECTION 6
INSTRUMENT
OPTIONS
SECTION 7
REPLACEABLE ELECTRICAL PARTS
iv

208 Service
TABLE
OF
CONTENTS (
CONT . )
PAGE
SECTION 8
DIAGRAMS
&
CIRCUIT
BOARD
ILLUSTRATIONS
SECTION 9
REPLACEABLE
MECHANICAL
PARTS
SECTION 10
ACCESSORIES
CHANGE
INFORMATION

208 Service
LIST OF ILLUSTRATIONS
FIGURE NO .
PAGE
Front ispiece
208
Storage Monit or .
viii
1-1
Dim ensional
drawing .
1-7
2-1
Front
panel .
2-1
2-2
Partial
front
panel
.
2-2
2-3
Rear
panel
.
2-3
2-4
2-4
2-5
2-5
3-1
3-2
Batt ery
replacem ent .
AC Adapt er
connect ed to
m onit or
.
Sim pli fied block diagram .
Audio circuit sim pli fied diagram .
Erase and Storage t im ing diagram .
Swit ching circuit sim pli fied diagram .
3-2
3-5
3-3
3-8
3-4
3-9
4-1
Board locator .
4-4
4-2
Term inal
connect ors .
4-5
4-3
Push - but t on swit ch rem oval and re - inst allat ion .
4-9
4-4
4-10
LED
replacem ent
.
Power
supplies
referenced
to +5.6
volt s .
4-5
4-14
4-6
Power
supplies
referenced to
-7 volt s .
4-14
4-7
Power
supplies
referenced
to -7
volt s .
4-15
5-1
5-3
Operating
current test
setup .
Test setup
for m easuring
gain . 5-2
5-5
5-3
ECG test cable
.
5-6
5-4
Signal
out
cable
.
5-6
5-5
5-9
5-6
5-11
5-7
5-12
Test setup for
adjust ing
charge
offset .
Display
of
sim ulat ed
pacer
pulse
baseline
offset .
Typical
display
of sag for
inst rum ent s
wit h Audio
board .
Typical
display
of sag
for
inst rum ent s wit hout
Audio
board .
Typical
display
of sag for
inst rum ent s
wit hout
Audio
board .
Test
setup to
check
Lead
Fault .
5-8
5-12
5-9
5-12
5-10
5-13
5-11
CMRR test fi xt ure
.
5-13
5-12
Test
setup to m easure
leakage
at 120 volt s
ac .
5-14
Sect ion 8 fi gures are located near their associated diagram on the
foldout
pages
.
Sem iconduct or lead configurations .
8-1
8-2
ECG board adjust m ent locations and test points .
vi

208 Service
LIST
OF
ILLUSTRATIONS
(
CONT
. )
FIGURE NO .
PAGE
8-3
8-4
8-5
8-6
8-7
8-8
8-9
8-10
Swit ch
board
test
points .
Storage board adjust m ent locations and test points .
Main
board adjust m ent
locations and test
points
.
Block
diagram
.
A1
ECG
circuit
board
.
A6 Audio circuit board .
ECG
board volt age and
waveform test
points .
A2 Main circuit board .
A4 Swit ch circuit board .
Main
board volt age and
waveform test
points
.
A3 Storage circuit board .
A2 Main circuit board .
A5 Batt ery Interface circuit board .
Main board volt age and waveform test points .
Troubleshooting chart .
8-11
8-12
8-13
8-14
8-15
8-16
8-17
10-1
10-2
10-2
Monit or holder m ount ing kit inst allat ion .
Monit or
holder
inst allat ion
.
ECG
cable
.
10-2
10-3 10-3
10-4
Pulse
sensor
.
10-3
LIST OF TABLES
TABLE NO .
PAGE
1-1
1-2
1-2
1-5
1-3
1-6
2-1
2-4
Electrical
Environm ent al
Physical
Typical Derat ing of Operating Tim e for Various Charge and
Operating
Tem perat ures
Routine Maintenance Schedule
Power Supply Operating Tolerance
Internal
Supplies
Option Inform at ion Locator
4-1
4-1
4-2
4-13
5-1
5-4
6-1
6-2
vii

208 Service
TEKTRONIX
SIZE
DISPLAY
SAVE
/
SEC
12.5
25.0
FULL
SPLIT
LOW
BATT
PWR
ON
OFF
SAVE
LEAD
FAULT
POS
PULSE
ECG
RE
2012
$
50
L.
NEART
RATE
BEATS
PER
MIN
AT
25m m
/
SEC
1923-03
208
Storage Monit or .
viii

Sect ion
1-208
Service
SAFETY
INFORMATION
AND
SPECIFICATIONS
SAFETY
INFORMATION
The 208
Storage Monit or has fully
isolated
ECG
(
Electro
cardiogram
)
circuitry
and
is
suit able for use wit h
elect rically
suscept ible patients when operated from eit her the int ernal
bat t eries or the
ext ernal AC
Adapt er .
When
using
these
power supplies , the ECG leakage current does not exceed
5uA rm s at 120 V , 60 Hz .
High
volt age
inside . Do
not rem ove
covers
.
Operating
volt ages
can
cause
injurious
or
fat al
elect ric
shock .
Refer
servicing to
qualified personnel .
DO NOT STERILIZE . See Sect ion 4 for
cleaning and
m ai nt enance
procedures .
Electrical
appliances
applied
to
a
patient can
creat e
hazards
for
bot h
patient and
operator
unless
the
equipm ent is
suit
able for
the
applicat ion and
the
operator is
skilled in its use .
Several
appliances
used
sim ultaneously can
com pound the
hazards
.
Follow the
inst ruct ions in
this
m anual
carefully to
insure safe
operation
of the
208 Storage
Monit or
.
a
See
Sect ion 10 for
a list
of
Tekt ronix -
approved
patient
cables and
accessories .
Power
Source
Safety
The 208
Storage
Monit or
is
designed
to
operate from
int ernal
bat t eries
and
need not be
connect ed
to
an ac
power
source .
It can also
be
operated from
the AC
Adapt er or
wit h the
opt ional
Batt ery
Charger
connect ed to
an ac
power
source
.
Both
the
AC
Adapt er
and
the
opt ional
Batt ery
Charger
are
int ended to be
operated
from
a
single
-
phase
eart h
-
referenced
power source having one current - carrying conductor ( the
Neutral
Conduct or
)
near eart h
pot ent ial
.
Operation
from
power sources where bot h current - carrying conductors are
live wit h respect to eart h ( such as phase - to - phase on a three
phase system ) is not recom m ended , since only one Conduct or
has fuse
protect ion
wit hin
the AC
Adapt er
and the
Batt ery
Charger
WARNING
The
m onit or is not
explosion
proof
.
When
used
in
locations wit h
flam m able
anest het ics , the
m onit or m ust be at least fi ve feet above the
floor
.
See
NFPA No.
56A ,
Standard for
the use
of Inhalation Anest hetics , articles 24114 ( c ) and
24032.1
The
m onit or is
com pat ible wit h
isolated
power
syst em s
such
as
used in
operating room s .
WARNING
If the
m onit or is
dropped or
severly
abused
, it
should
be
checked by
qualified
personnel to
ensure that the safety features are int act .
The
const ruct ion
of the
m onit or provides
protect ion for
bot h
patient and
operator .
The
only
precaution
necessary
during
operation
is to
m ak e sure that
the AC
Adapt er
or
Batt ery
Charger ( when used )
is
connect ed
to
a safety ground
.
1
Safety Docum ent s : Additional safety inform at ion can be found in the followi ng docum ents :
Nat ional Fire Prot ect ion Association , 60 Bat terym arch Street , Boston , Massachusetts , 02110
NFPA No. 76B - T , Safe Use of Electricity in Hospitals , 1973 .
NEPA No. 56A , Standard for the Use of Inhalation Anest hetics , 1972 .
NFPA No. 70 , Nat ional Electrical Code ( Article 517 ) , 1971 .
Underwrit ers ’
Laborat ories ,
Inc.
UL 544 , Standard for Safety , Medical and Dental Equipm ent .
1-1

Safety Inform at ion and
Specifications
- 208
Service
SPECIFICATIONS
The
followi ng
elect rical
charact eristics
apply over an
am bi ent
t em perat ure
range shown in
Table 1-2
when the m onit or
has
been
calibrat ed in
a + 25  C ,
+ 5  C
envi ronm ent
.
TABLE
1-1
Electrical
Characteristic
Perform ance
Requirem ent
Supplem ent al
Inform at ion
VERTICAL INPUT - TO - OUTPUT
TRANSFER CHARACTERISTICS
Input to Display and Input to
SIG OUT
Bandwidt h
Low
Frequency
0.2 Hz or less . Wit hout audio ( Option
31 ) has swit ch
for 0.05 Hz
or less .
High Frequency
ECG
100 Hz .
Pulse
40 Hz .
CMRR
Great er
than 500,000 : 1
at 60 Hz
wit h 15
KS2
m axim um
elect rode
resist ance and
5
kS2 im balance .
Great er
than
10
MS .
ECG
Differential
Input
Resist ance
Input
DC
Offset
No degradat ion of signals having up to
100 m V dc
offset .
Overdrive
Recovery
Display Display
on
screen
wit hin
3
seconds
after rem oval of 100 m V dc step on
inputs .
SIG OUT
Wit h SIZE at Maxim um : returns to wit hin
200 m V of
steady
state
in 3
seconds or
less after rem oval of 100 m V dc step at
inputs .
Wit h SIZE at Minim um : returns to wit hin
1.2 V of steady state in 3 seconds or less
after rem oval of 100 m V dc step at inputs .
1-2

Safety
Inform at ion and
Specifications
-
208
Service
TABLE 1-1 ( cont . )
Characteristic
Perform ance
Requirem ent
Supplem ent al Inform at ion
Input
to
Display
Deflection Factor
ECG
Variable
wit h
SIZE cont rol
from :
full
screen
display
, wit h
520 UV
input ( 6.3
cm / m V ) to 0.83 cm display wit h 2 m V
input ( 0.42 cm / m V ) in FULL m ode .
Pulse
15 : 1 .
Input
to SIG
OUT
Gain
ECG Input to SIG
OUT
X1000
and X1 ,
wit hin 5 % ,
int o
open
circuit
.
Pulse Input to SIG
OUT
16 m V input causes a 1 V output , wit hin
20 % at
X1000 jack .
Output
Im pedance
Output m ay be short circuited wit hout
dam age to
the
inst rum ent .
X1000
2 k12 , wit hin 5 % . 1
X1
1 k12 , wit hin 5 % .
1
Output DC Level ( no
signal )
OV , wit hin 50 m V .
Output Signal
Linear
Range
Wit hin
2.2
V to 3 Hz
,
increasing at a rate
of 0.5 V per Hz to wit hin 10 V.
Wit hin 14 V.
Max
Output
Voltage
( off - screen or fault
condit ion )
Leakage
Current
Less than 5uA rm s at 120 Vac , 60 Hz .
Self
Prot ect ion
Defibrillator and
Cauterizer
Inst rum ent m ay
rem ai n
connect ed to No dam age to inst rum ent when patient
patient during defibrillation and elect ro- cable has 1000 12 in series wit h each
cautery when
used wit h
a Tekt ronix
elect rode
.
Resist ors in
cable
can
open in
patient cable
.
ext rem e cases . Recovery to norm al display
in 5
seconds or
less .
Pulse
Input
The
m etal
case
of
the
approved
pulse
sensor is connect ed directly to inst rum ent
com m on . If the 208 is used wit h connec
tion to
auxiliary equipm ent , such as
ex
ternal power supply or chart recorder , the
auxiliary equipm ent m ust m eet safety
requi rem ent s for direct connect ion to the
patient .
@
1-3

Safety
Inform at ion and
Specifications -
208
Service
TABLE 1-1 ( cont . )
Characteristic
Perform ance Requirem ent
Supplem ent al
Inform at ion
VERTICAL
Positioning
Wit h no
signal
applied , POSITION
cont rol
capable
of
posit ioning
baseline
to
wit hin
1/ 4 screen height
of the top
and the
bot t om
of the crt
grat icule
.
Trace Shift
Between
Upper
and
Lower Screen in Split Screen
Mode
0.65 inch ,
wit hin 0.065
inch ( 16.5 m m
,
wit hin 1.7 m m ) .
X2 ,
wit hin 8 % .
7
Gain Change from Split Screen
to Full - Screen Mode
Size Balance
Vertical trace shift wit h variation of size
cont rol , 0.1
inch ( 2.5
m m ) , 0.2 Hz
m ode .
Size
Control
Range
From m inim um size to m axim um size ,
deflect ion factor
increases at
least 15 t im es .
SWEEP
Speeds
12.5 or 25 m m / second .
Wit hin 5 % .
Triggering
Free
run .
Sweep
Start
Wit hin 0.078 inch ( 2 m m ) of edge of
phosphor .
Sweep
End
Wit hin 0.078
inch ( 2 m m ) of
edge of
phosphor .
AUDIO
Tone
On when MONITOR swit ch is in
MONITOR
posit ion .
Output
level
cont rolled by
SIZE
cont rol .
Tone em it t ed only during dynam ic signal
on screen
. " Click "
sound em it t ed for
pacer
signal
.
INTERNAL BATTERY
Type
Two
rechargeable
nickel -
cadm i um
D size
cells .
Special high - t em perat ure cells required .
Typical
Operating Tim e
At least two hours ( charge and
operation
at
+
20  C
to
+
30

c ) .
Operating the inst rum ent at t em perat ures
below + 5  C reduces operating t im e and
operating at -15  C can reduce operating
t im e by 15 % .
Operating
Current
Drain
Not m ore than
2.0 A at 2.5 V
, or 2.1 A
at
2.0 V.
Operating Voltage Range At least 1.9 V
for
inst rum ent
operation
,
to at least 3.0
V for fully
charged bat t ery .
1-4

Safety Inform at ion and Specifications - 208 Service
TABLE 1-1 (
cont
. )
Characteristic
Perform ance
Requirem ent Supplem ent al Inform at ion
350
m A
.
Max Acceptable Batt ery Over
charge
Current
LOW
BATT Condition
Indicator
Low bat t ery
causes
indicator to be on
steady
.
Display or SIG
OUT
m ay
cont ain
spurious
responses wit h low bat t ery volt age .
Deep Discharge Prot ect ion
Inst rum ent
operation is
aut om at ically
int errupt ed
when
bat t ery
volt age
drops
to 1.5 V wit hin 0.3 V.
Recharge
Tim e at
+ 25  C
Batt ery charging should be done in an
am bi ent t em perat ure between + 5  C and
+ 30  C
.
The
greater the
t em perat ure
above
+ 25 
C ,
the less
charge
the
bat t ery
accepts ,
regardless
of
ext ended
charge
t im e .
Charging at + 55  C
can
reduce
operating
t im e by approxim at ely 50 % .
AC
Adapt er
16
hours
.
Inst rum ent
m ay be
operated
during
charge .
16 hours wit h Monit or off .
Batt ery
Charger
(
Option
31 )
Monit or operating t im e is ext ended by
15 % if charger is plugged in wit h Monit or
operating .
TABLE 1-2
Environm ent al
Characteristic
Perform ance
Requirem ent
Supplem ent al
Inform at ion
TEMPERATURE
See supplem ent al inform at ion under
Recharge Tim e
.
Operating from bat t ery -15  C to
+ 55  C ( + 5
 F to + 131
 F ) .
Operating from AC Adapt er
+ 5  C to + 40  C
( + 41  F to + 104
 F ) .
Nonoperat ing
-40  C to + 60 
C ( -40  F to +
140  F ) .
ALTITUDE
Operating
To 15,000 feet .
Maxim um
operating
t em perat ure
de
creases by 1  C ( 1.8  F ) per 1000 ft . above
5000 ft .
Nonoperat ing
50,000 feet m axim um .
HUMIDITY
5
cycles
of
+ 30  C to +
50  C ( 120
hours ) at 95 % relative hum idit y .
Reference MIL - E - 16400F .
1-5

Safety Inform at ion and Specifications - 208 Service
TABLE 1-2
( cont . )
Characteristic
Perform ance
Requirem ent Supplem ent al
Inform at ion
VIBRATION
Operating and Nonoperat ing
15 m inutes
along each
of the three
m aj or
axes at
a
tot al
displacem ent
of
0.025
inch
p
- p ( 4 g’s
at 55
Hz )
wit h
frequency
varied
from 10 to 55
to
10 Hz in 1 m inute sweeps . Hold for
3 m inutes at 55 Hz . All m aj or reson
ances
m ust
be
above
55
Hz .
SHOCK
Operating and Nonoperat ing
Two shocks at 150 g’s , 1/ 2 sine , 2 m s
durat ion in each direction for a tot al
of 12
shocks .
TRANSPORTATION ( packaged )
Qualifies under Nat ional Safe Transit
Com m it tee test procedure 1A .
TABLE 1-3
Physical
Characteristic
Perform ance
Requirem ent
Height
Width
See
Dim ensional
Drawing
,
Fig . 1-1 .
Depth
Weight
(
wit h bat t eries
)
Approxim at ely
3.5
lbs ( 1.6 kg
) .
1-6

5.000
"
(
127
m m
)
10.500
"
(
267
m m
)
2.100
"
(
54
m m
)
-
1.340
"
(
34
m m
)

 
2.480
"
(
63
m m
)
Fig . 1-1 . Dim ensional drawing .
3.880
"
(
99
m m
)
2.063
"
(
52
m m
)
25


1.400
"
(
36
m m
)
4.590
"
(
117
m m
)
Safety
Inform at ion
and
Specifications
-
208 Service
1923-04
1-7

Sect ion 2 208 Service
OPERATING
INFORMATION
CONTROLS
,
CONNECTORS
,
AND
INDICATORS
4 )
PULSE -
ECG -
Select s
eit her the
PULSE or
the
ECG
input . Push
in for
PULSE
. Set
out (
yellow band
showing
) for
ECG
.
This
sect ion
explains
the
funct ion of
each
ext ernal
cont rol ,
connect or
,
and
indicator that
appears on the
ext ernal surfaces
of the
m onit or
and is
used
during
norm al operation .
Controls
located
inside the
inst rum ent
covers
should be
adjust ed
only
during
calibrat ion . Display
funct ion
push
but t ons have a
yellow band to
indicate
the
out
posit ion .
5 )
LEAD
FAULT
-
This
indicator light s to
indicate a
problem in the ECG
input
circuit
.
Several
possibilit ies
are :
a . An open circuit ( break ) in the patient cable or
in the
elect rodes or
elect rode wires .
Front
Panel ( Fig .
2-1
and 2-2 )
1 )
SAVE A -
Saves
the
upper
segm ent
of
the crt
display
when
in
the
split
-
screen
m ode or
bot h
segm ent s
when
in the full - screen m ode . Set in for save . Set out
(
yellow band
showing ) for
non - save .
b .
Insufficient gel or
paste in the
elect rode
( s ) .
2 )
SAVE
V -
Saves the
lower
segm ent
of the
crt
display
when in the
split - screen
m ode or
bot h
segm ent s when
in the full -
screen m ode . Set
in for save .
Set out
(
yellow
band
showing
)
for non -
save .
c . One or m ore elect rodes or elect rode wires dis
connect ed (
three
elect rodes are
required for
proper
operation )
3 )
FULL
-
SPLIT -
Select s
eit her
a
split
-
screen or a
full
screen display
. Set in for
full - screen display
. Set out
(
yellow band
showing
)
for split -
screen
display
.
d .
Excessive dc
offset
in one
or m ore
elect rodes
(
refer
to
Sect ion 10 for a
list of
recom m ended
elect rodes ) .
DISPLAY
TEKTRONIX
1
SIZE
SAVE
3
m m / SEC
FULL
SPLIT
12.5
25.0
2
LOW
BATT
SAVE
PWR
5
ON
OFF
LEAD
FAULT
4
PULSE
ECG
POS
30
REF
180
120
80
60
50
40
L
HEART RATE
BEATS
PER MIN
AT 25m m /
SEC
1923-08
Fig . 2-1 . Front panel .
2-1

Operating
Inform at ion
- 208
Service
e . The SIZE cont rol is set so far clockwise that the
waveform will not fi t on the display screen .
9 ) m m / SEC
- Select s
eit her 12.5
m m / SEC
( pushed
in ) or
25.0 m m / SEC ( set out , yellow band showing ) sweep
speeds .
f . The Cardiosensor is not m ak ing proper cont act
wit h the patient ( elect rode gel or wat er on the skin
will insure better
cont act between
the Cardiosensor
and
the
patient
)
.
10 ) PWR - ON - OFF - Turns the m onit or on ( push but t on
set in ) or off
( set out ,
yellow
band
showing )
. Must
rem ai n in
the out
posit i on
( m onit or
off ) for
at least
2
seconds to
reset the
int ernal
protect ion
circuit
.
If the
power is
turned on
too
soon (
wit hin 2
seconds )
after
turning the power off , the m onit or will not operate . 6 HEART RATE BEATS PER MIN Scale - The display
grat icule
( screen
) is m arked in beat s
per m inute
for
direct reading at the 25.0 m m / SEC sweep speed
( m m / SEC push but t on set out , yellow band showing ) .
To read the display at the 25.0 m m / SEC sweep speed ,
note the point
on the
waveform which crosses
the
reference line , then note the scale reading where the
fi rst sim ilar point on the waveform occurs . To read
the display at the 12.5 m m / SEC sweep speed , locate
the second sim ilar point on the waveform and read
the rate from
the scale
.
11 LOW BATT - Indicator light s when bat t ery volt age is
low indicating the need for the bat t eries to be recharg
ed or changed .
Rear Panel ( Fig . 2-3 )
12 ) BATTERY ACCESS Door - Two special rechargeable
D cells (
Tekt ronix
part
146-0005-00 )
are
housed be
hind this door . Press appropriat e arrow to open or
close
door .
7 POS - Changes the vert i cal posit i on of the signal dis
played
on the
screen
.
13 ) CHARGE - Provides input for the standard AC Adapt er
or the opt ional Batt ery Charger accessory .
8 SIZE - Changes the am plit ude of the displayed wave
form . Set fully counterclockwise when not in use .
14 ) PULSE - Provides input for an opt ional pulse sensor .
15 ) ECG - Provides input for an ECG patient cable or
Cardiosensor .
6
16 ) ECG 1 m V Cal Push Butt on - Pressing this push but t on
insert s a 1 m V step in the ECG input which is display
ed on the crt .
This results in
a 1 V step and
a 1 m V
step at the SIG OUT
connect or which
can be used
to
calibrat e
chart
recorders and ot her
inst rum ent s .
VIX
SIZE
8
m m / SEC
9
12.5
25.0
LOW
BATT
11
17 MONITOR - Select s audio signal in the MONITOR
posit i on .
In
inst rum ent s
wit hout
audio (
Option 31 ) ,
the MONITOR swit ch select s a low frequency cut off
of eit her 0.05
Hz or 0.2
Hz . Use the
MONITOR
posit i on
wit h
the Cardiosensor
in inst rum ent s
wit hout
audio
.
PWR
ON OFF
( 10
7
POS
40
30
T 25m m / SEC
18 SIG OUT - This connect or provides an output signal
of eit her
1
t im es
or
1000
t im es the ECG
elect rode
signal and
an
output
signal of sim ilar
am plit ude
from
the
opt ional pulse sensors .
1923-28
1
Fig . 2-2 , Partial front panel .
0.05 Hz to 100 Hz ( cycles per second ) bandwidth from  Recom
m endat ions for Standardization of Inst rum ent s in Electrocardio
graphy and
Vect orcardiography
" , by the
Am erican Heart
Associa
tion Inst rum ent at ion Com m it tee on Electrocardiography . I.E.E.E.
TRANSACTIONS ON BIOMEDICAL ENGINEERING , Jan , 1967 .
2-2