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OPERATING
AND
SERVICE
MANUAL
AC
VOLTMETER
4038
,.S"tIS
i I f I
J /
0
ON
un
lUT
CI.VIlI,,'
FUNCTION
0"
INPUT
HEWLETT~PACKARD
=
HEWLETT
The
Hewlett-Packard
thoroughly tested
specifications when it
Packard
ments
the
Company
are
traceable
extent allowed
and
further certifies that its calibration
iI
CE
RTIFICATION
Company
inspected
was
shipped
to
the
U.S.
by
the
Bureau's calibration facility.
PACKARD
certifies that
and
found
from
National Bureau of Standards
the
this
to
meet its
factory.
instrument
published
The
Hewlett-
measure-
was
to
WARRANTY
All
Hewlett-Packard products
materials and workmanship. This
from .tne
nents listed
will repairorreplace products which prove tobedefective during
the
Packard.
liable for consequential damages.
Service contracts
for Hewlett-Packard products
pair
For
Service Office. Addresses
dateofdelivery, or,inthe case of certain major compo-
in
the operating manual, for the specified period.
warranty
on-site.
any assistance, contact your nearest Hewlett-Packard Sales and
No
period
other
provided
warrantyisexpressed
or
customer assistance agreements
AND
are
providedatthe back of this manual.
ASSISTANCE
are
warranted against defects
they
that
warranty
are
require
applies for one year
returned
or
implied.
maintenance
to
We
are
We
Hewlett-
are
not
available
and re-
in
OPERATING
-hp-
AND
SERVICE
Part No. 00403-90010
MANUAL
MODEL
AC
VOLTMETER
Serials Prefixed: 0986A
If
other
quire modification
manual, the changes will
appear in Appendix C or
in an associated "Manual
Changes" supplement.
4038
serial prefixes re-
of
this
Copyright Hewlett-Packard Company 1962
301,
P. O. Box
Loveland, Colorado, 80537 U.
S.A.
Printed: January 1973
Mode1403B
Table
of Contents
Section
I GENERAL INFORMATION
1-1.
1-5.
1-7.
Description.
Instrument
Identification.
Accessories
: . . . .
and Manual
• . . .
Available.
Section
II INSTALLATION
2-1.
Inspection
2-4.
Power
2-6.
Installation
2-8.
Repackaging
.•....
.•..•..
Requirements
For
Shipment.
Section
ill
OPERATING INSTRUCTIONS
3
-1.
3-3.
3-5.
3-7.
3-9.
3
-11.
3-13.
3-18.
3-21.
3-24.
3-27.
3-28.
Introduction
Front
Operating
Battery
Instrument
Input
Protection
Voltage
Waveform
Decibel
Impedance
Current
Clip
. . . . . .
Panel
Description.
Procedure.
Charging
Temperature
Measurements
Errors
Measurements
Correction
Measurements
-On
Probe.
Information.
. • . .
Section
IV THEORYOFOPERATION
4-1.
4-3.
4-6.
4-11.
4-20.
4-25.
Introduction
Preliminary
Input
Circuit.
Intermediate
Meter
Power
Attenuator
Rectifier
Supply
.•....
• • . . .
Attenuator
Circuit
...•..•.
..
..••.
.
.
. . .
Limits
Graph
. . . .
. . . . .
..
.
.•
TABLE
..
.
.
.
Page
1-1
1-1
1-1
1-1
Page
2-1
2-1
2-1
2-1
2-1
Page
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-4
3-4
3-4
3-4
Page
4-1
4-1
4-1
4-1
4-2
4-2
4-3
OF
CONTENTS
Section
V MAINTENANCE .
5-1.
Introduction
5-6.
Test
5-8.
5-10.
5-12.
5-13.
Instruments
Meter,
Performance
Calibration
Frequency
Mechanical
5-16. Noise Check .
5-17.
5-18.
Input
Adjustment
Resistance
Procedures.
5-20.
5-21.
5-23.
5-24.
5-25.
5-26.
5-27.
5-29.
5-30.
5-31.
5-33.
5-35.
5-37.
Power
Supply
Input
Resistance
Overload
Calibration
High
Frequency
30-
Volt
Troubleshooting
Repair
..•.............
Cabinet
Servicing
Transistor
Function
Fluorescent
Section
VI REPLACEABLE PARTS
6-1.
Introduction.......
6-4.
6-6.
Ordering
Non-Listed
Information.
Appendix
OF
A CODE LIST
B SALES
AND
MANUFACTURERS
SERVICE
C MANUAL BACKDATING CHANGES
Required.
Checks
Checks .
Response
Check
and
Calibration
. . . . . . . .
Adjustment
.....
Check. . .
and
Tracking.
Response
Response
. . . . . . . . . .
Removal
Etched
Circuit
Replacement
Switch
Repair
Indicator
..
Parts
...
OFFICES
.
Zero.
.
Checks.
..
Calibration
Boards
Decal.
.
Page
5-1
5-1
5-1
5-1
5-2
5-2
5-2
5-3
5-3
5-3
5-3
5-4
5-4
5-4
5-5
.
5-5
5-5
-
5-6
.
5-6
5-6
5-7
.
5-7
.
5-7
Page
6-1
6-1
6-1
6-1
Number
1-1.
Specifications.
1-2.
Accessories
3-1.
EffectofHarmonics
Voltage
3-2.
Examples
5-1.
Test
Instruments
. . . . . • . . . . . .
Available
on Model 403B
Measurements
of Voltage andDBMeasurements.
Required
Number
1-1.
Model 403B
Voltmeter.
3-1.
Front
3-2.
Voltage
3-3.
Model403Blmpedance
4-1.
Model403BFunctionaiBIockDiagram
4-2.
Input
4-3.
Diode
4-4.
Fixed
4-5.
Meter
Transistorized
• . . . . . . . . . . . . .
Panel
Description
Measurements.
Amplifier.
Current
Vs Diode Voltage
Amplifier
Rectifier,
. . • . • . . . . .
Block
Simplified
.•...••..
•.••••.
.....•..•
LIST
AC
....•.....
. . . • . . . . . . 3-3
Correction
Graph..3-5
.•.
..
Diagram.
Diagram
. . .
...
LIST
OF
Page
.
1-1
.•
1-2
3-4
3-4
5-1
OF
ILLUSTRATIONS
Page
1-0
3-2
4-0
.
4-1
4-2
4-2
4-3
TABLES
Number
5-2.
5-3.
5-4.
5-5.
6-1.
6-2.
Number
4-6.
5-1.
5-2.
5-3.
5-4.
5-5.
5-6.
5
-7.
5-8.
6-1.
Calibration
Troubleshooting.
Test
Transistor
Replaceable
Mechanical
Meter
Model 403B
Check
Procedure
Replacement.
Parts.
Parts
Rectifier
Top
Table.
. . . . . . . . .
Troublesliooting .
Circuit.
View.
Model 403B Bottom View
Overload
Performance
Frequency
Range SWitch
Function
Schematic
Check Setup . . . •
Check
Detail
Detail.
Setup.
Setup
. . .
Response
Switch
Diagram
Exploded View .
. . . . . .
••••.
.
•
. • •
. . .
Page
5-2
5-6
5-6
5-7
6-2
6-5
Page
4-3
5-0
5-2
5-4
5-4
5-5
••
5-8
5-9/5-10
5-9/5-10
..
6-7
iii
Section
I
8
J
I
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,
I
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r
1
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'''1100
Model403B
Model
403B
standard
Ac
Voltmeter
RANGE
VOLn
oe
Model 403B
Option 01
Ac
Voltmeter
1-0
Figure
1-1.
Model 403B
Ac
Voltmeter
Model403B
Section I
GENERAL
1-1.
DESCRIPTION.
1-2.
The
-hpmeterisa
rms
valuesofac
The
instrument
300
volts
The
Model 403B
scaleinvolts
faceiscalibrated
403B and 403B Option 01
specifications
1-3.
The
batteries.
tained
battery
volts
ac.
1-5.
INSTRUMENT
IDENTIFICATION.
1-6.
Hewlett-Packard
ber.Ifthe
numberonyour
RANGE:
O.
001to300
1, 3,
FREQUENCY RANGE:
5 Hz
ACCURACY:
%of
MODEL 403B ACCURACY SPECIFICATION
Frequency
10Hzto
5to10
and
1to2 MHz
MODEL 403B OPTION
CATION
Frequency
10Hzto
Model 403B
general
(-72
Model403B
The
10
to
Full
purpose
voltagesinthe
has
full-scale
dBmto+52dBm)ina
meter
(rms);
with
are
giveninTable
instrument
charger
first
section
instrument
volts
sequence.
2 MHz
Scale.
1 MHz
Hz
1 MHz
Transistorized
instrument
ranges
faceiscalibrated
the
Model 403B Option01meter
the
upper
are
showninFigure
operates
AND
usesatwo-section
rms
from
also
which
operateson115or230
MANUAL
(serial
does
full
o
to
50
±2%
±5%
01
ACCURACY
o
to
50
±0.2
dB
that
5Hzto2 MHz
from
1,3,10
scaleindB.
1-1.
Nickel
includesaself-con-
prefix)ofthe
not
agree
scale
(12
0
C o
0
C o
AC
measures
range.
1 mV
sequence.
with
the
Models
1-1,
Cadmium
serial
serial
with
Table
ranges)
to
-20oC
±8%
±8%
SPECIFI-
o
to
-20
±0.7
dB
SECTION
INFORMATION
on
Volt-
to
upper
and
numthose
1-1.
in a
plied
tween
in
ter
letter
was
1-7.
1-8.
the
1-9.
accessories
accessories.
Specifications
NOMINAL INPUT IMPEDANCE:
OVERLOAD PROTECTION:
DC
POWER SUPPLY:
TEMPERATURE
c
DIMENSIONS:
I
the
title
page of
with
the
your
this
separating
indicates
manufactured.
ACCESSORIES
To
following
a.
b.
c.
Table
2
megohms;
toO.03-volt
300-volt
Fuse
ISOLATION:
Signal
chassis.
rechargeable
4
operation
to
500
20,000
tained
mentisoperated
48to440 Hz, <3
o
-20
5-1/8
manual
instrument
manual.
C
the
increase
accessories
-hp-
Model 11005A Line
former.
-hp-
Model 11039A
Divider.
-hp-
Model 10111A
Adapter.
1-2
provides
mentioned
shunted
ranges,
ranges.
protected:
ground
per
recharging
hours).
and
functions
to
+50oC.
in. wide,
this
manual,
will
define
and
the
Some
serial
two
the
countryinwhich
AVAILABLE.
the
usefulnessofyour
aboveaswellasother
maybe±500 Vdc
batteries
recharge
cycles
Recharging
automatically
fromacline
watts).
RANGE:
6-3/32
Model 403B
numbers
sectionsofthe
are
available:
Capacitive
BNC-To-Binding
information
by <60pFonO.
< 30
pF
(furnished).
(20
hoursat-200C), up
(expected
circuitisself-con-
in. high, 8 in.
change
the
differences
may
number.
the
Bridging
Voltage
and
onO.1-volt
(115or230V
001-volt
from
battery
when
sheets
instrument,
deep.
sup-
described
have a
instrument
Trans-
Post
useofthe
useful
to
external
40-hour
life
of
instru-
±10%
This
be-
let-
5
to10Hz
and
1to2 MHz
METER:
Individually
average
in
the
rms
calibrated,
value
value
of input
of a
±0.4
dB
taut
waveform
sine
wave.
±0.7
band.
Responds
andiscalibrated
dB
ACCESSORIES AVAILABLE:
-hp-
11002A
plugtoalligator
5 ft. long,
to
clip.
ACCESSORY FURNISHED:
Detachable
Test
dual
power
Leads,
clips.
banana
cord.
5
ft.
long,
-hp-
11003A
plugtoprobe
dual
Test
and
banana
Leads,
alligator
1-1
Section
I
Table
1-2.
Accessories
Available
Model403B
Model No.
11002A
11003A
1l01lA
1l005A
1l039A
456A
11004A
Test
Leads
Adapter
Line
Bridging
Provides
to
unbalanced
measurements
Capacitive
(Division
Current
AC
1
mY/rnA
Line
Matching
Provides
input
put
for
lines.
Use
Transformer
balanced
Voltage
ratio:
600
600-ohm
on
balanced
Divider
1000:1)
-ohm
output
lines.
Probe
±1%at1 kHz
Transformer
to
balanced
600
ohm
135or600
unbalanced
measurementsonbalanced
input
for
ohm
out-
Dual
Banana
Dual
Banana
Binding
Terminating
Frequency
Power
PlugtoAlligator
PlugtoProbe
PosttoBNC
Resistance:
Range: 20 Hzto45 kHz
Handling
Capacity:
Accuracy:
Capacity:
Input
Max. Voltage Rating:
22 kV, 1 MHz 20 kV,
Resistance
<
50
milliohms
Terminating
Frequency
Power
Resistance:
Range:
Handling
Capacity:22dBm
Features
and
600or10Kohms
+15
±3%
15pF± 1
60
10
Max.
Current
1
amp
rms
1. 5
amp
600or10Kohms
5 kHz
Clips
Alligator
dBm
Clip
(4.5Vinto
600n)
pF
Hz 25 kV, 100 kHz
MHz15kV, 20 MHz 7 kV
Accuracy
±2%
peak
100 Hzto3 MHz
to
600 kHz
(10 V into 600
n)
1-2
Model403B
section
II
2-1.
INSPECTION.
2-2.
Unpack
it
for
panel
knobs
file a
claim
pageonthe
2-3.
An
soonaspossible
inspection,
tionV,Paragraph
2-4.
2-5.
Theacpower
current
ment
can
Hz,
source.Aswitch
the
instrument
volt
modesofoperation.'
the
signsofphysical
etc.Ifthereisany
with
back
electrical
performance
POWER
tothe
Nickel-Cadmium
be connectedtoa
allows
WHEN THE 403B IS USED WITHOUT
THE POWER CORD, THERE
GROUND RETURN.
TO AVOID
instrument
the
carrier
sideofthe
inspection
after
5-10.
REQUIREMENTS.
circuit
I
WARNING
ELECTRICAL
upon
damage
and
refertothe
front
coverofthis
shouldbeperformed
receipt.
checks
which
batteriesinthe
115-or230-
locatedonthe
the
usertoselect
USE
SECTION
INSTALLATION
receipt
suchasscratched
apparent
To
are
and
inspect
damage,
warranty
manual.
aid in
electrical
includedinsec-
provides
rear
charging
instru-
volt, 48 - 440·
panel
115-or230-
I
IS
NO
CAUTION
SHOCK.
II
2-8.
REPACKAGING
------NOTE
If
the
instrumentistobeshipped
Hewlett-Packard
pair,
attachatagtothe
identifying
the
as
2
-9.
The
for
shipment.Ifyouhaveany
local
of
-hp-
for
office
a.
If
original containerisnot
b.
c.
serviceorrepairtobe
plished;
and full
ment.Inany
tify
the
instrument
serial
number
prefix.
followingisa
Sales
and
locations.)
Place
instrumentinoriginal
able.Iforiginal containerisnot
one
canbepurchased
Sales
and
Wrap
instrument
fore
placinginan
Use
plenty of packing
of
instrument
board
strips.
FOR
the
owner
include
serial
number
correspondence,
and
general
service
service
in heavy
and
protect
SHIPMENT.
-----
for
serviceorre-
and indicating
the
model
ofthe
by model
serial
guide
questions,
Office.
from
your
Office.
used,
inner
container.
material
panel
to
instrument
accomnumber
instru-
iden-
number,
number
for
repacking
contact
(see
Appendix B
containerifavail-
available,
nearest
paperorplastic
around
faces
-hp-
all
with
your
be-
sides
card-
2-6.
INSTALLATION.
2-7.
The
-hpthereforenospecial
the
instrument
bient
temperature
Model 403Bisfully
should notbeoperated
coolingisrequired.
exceeds
500C (1310F).
transistorized;
However,
where
the
am-
d.
Place
instrument
cartonorwooden box and
tapeormetal
e.
Mark
strument,
shipping
bands.
"
"Fra~ile"
and
inner
container
etc.
container
seal
with
'Delicate
with
ina heavy
strong
In-
2-1
Model403B
section
ill
3-1.
INTRODUCTION.
3-2.
This
from
afterashort
60
seconds
3-3.
voltmeterisready
the
factory
warm-up
warm-up
FRONT
PANEL
and will give
period.
for
optimum
DESCRIPTION.
3-4.Adescriptionoffront
Figure
3-1.
The
that
accompanies
3-5.
OPERATING
3-6.
The
given in
photo
3-7.
3-8.
This
whenever
cord
Figure
that
BATTERY
The
instrumentiscontinually
the
connectedtoa 115or230 volt
eventofcomplete
after
twenty
descriptions
the
figure.
PROCEDURE.
operating
accompanies
403B
procedure
3-2.
Instructions
the
CHARGING
hasaself-contained
FUNCTION
discharge,
minutesofrecharging
connectedtoanacsource.
approximately60hours
when
the
charged.
Nickel Cadmium
(RefertoSection IV,
(depending on
THE FOUR NICKEL CADMIUM
TERIES
IN THE
-HP-
HERMETICALLY-SEALED CONTAIN-
ERS. UNDER
(ABOVE
HIGH
500C), HYDROGEN IN THE
HERMETICALLY -SEALED BATTERY
CONTAINER
CAN
PRESSURE, CAUSING DAMAGE TO THE
BATTERIES AND/OR INSTRUMENT.
(REFERTOSECTION IV, PAGE
3-9.
INSTRUMENT
3-10.
This
tations.
for
safe
o
+50
quite
limits
Internal
instrument
The
designofthis
and
C
stable
(-4to+1310F).
adequate
for
in mind when
temperatures
easytoobtainifthe
if
the
air
temperatureisquite
TEMPERATURE
has
operation
This
most
users;
operating
in
instrumentisleftinthe
practiceistobecertain
storedoroperatedindirect
sibilityofreduced
performance.
OPERATING INSTRUCTIONS
for
use
specified
Allow
panel
are
for
figure.
INFORMATION.
charging
switchisON
the
Complete
cells
are
Paragraph
403B ARE IN
TEMPERATURES
BUIlDUPTO LARGE
certain
instrument
over
temperature
however,
under
excess
that
the
sunlighttoavoid
upon
performance
approximately
performance.
controlsisgiven in
keyedtothe
the
Model 403B
are
keyedtothe
battery
the
and
source.
403B
canbeused
with
the
recharge
setting
completely
4-25).
BAT-
4-3.)
LIMITS.
temperature
has
the
range
of -20
range
keep
field conditions.
of 1220F
are
moderate.
instrumentisnot
When
using
SECTION
receipt
photo
is
charger.
batteries
the
line
In
the
line
cord
requires
of R39)
dis-
limi-
provided
to
is
these
quite
sun,
even
A good
the
pos-
403B
III
at
temperatures
are
fully
this
temperature.
3-11.
INPUT
3-12.A1/16Afuseisincludedinseries
input Circuit which
sive
overload.
netisremoved.
instrument.
3-13.
VOLTAGE
3-14. Always
or
higher
which have dc
the
appropriate
reading.
power
supply
age
maybeas
only a few
the ground
the
signal
3-15.
If
ance
cation
and
although
shunted
measurements
source,
because
voltmeter.
they
across
excessive
3-16.
The
effectively
city.
(This
hasareactanceof0.8
at
40 kHz,
higher
ranges
considered
in
circuitsofmoderate
3-17 .
severeRFcirculating
at
potentials
frequency
the
accuracyofthe
By
using
-hp-
a 10111A
the
accuracyofthe
3-18.
WAVEFORM
3-19.Inordertomaintain
ment, one
average
responding
calibratedintermsofthe
wave.Ifthe
contains
appreciable
voltages,
true
rms
value on
below
charged
priortosubjecting
PROTECTION.
will
This
fuseisaccessible
A
spare
MEASUREMENTS.
leave
making
levels
the
over25volts.
when
lower
This
practice
ripple
measurements
muchas600
millivolts.
strap
shouldbeconnected
groundisdc
hum
pick-up
of high
impedance
Shielded
will
cause
the
circuit
source,
loading.
rated2megohms
reduced
(above 1
factistrue
etc.
The
shunt
(see
when
Table
measuring
approaching
range.
These
403Bto±10% on
accessories
(adapter)
shunted
403B
must
remember
device,
waveformofthe
harmonicsorother
the
meter
indication
the
order
OOC,becertain
instrument
open with
repeatedorexces-
when
fuseisincluded
instrument
initial
onthe1-voltrange
connectionstocircuits
Then
rangetoobtainanup-scale
shouldbeused
when
where
volts,
but
theacripple
To obtain
specified
except
offset
from
chassis
are
made
fromahigh-imped-
can
affect
the
of both
leads
will
an
increaseinthe
with
input
kHz)
for
anyacvoltmeter.)
reduce
the
possibility
resistance
by shunt input
megohmat4kHz, 80,000
capacity
1-1).
impedance
300
severe
decreasesonthe
This
higher
factor
frequency
level.
currents
are
voltsinthe1to
ground
the
currents
300-volt
1000lA (10:1 divider) and
by a
2-megohm
canberetainedto±5%.
ERRORS.
accuracyofmeasure-
that
this
but
rms
instrumentisan
the
meter
value of a
voltage being
will
deviate
indicated by
the
batteries
with
the
cabi-
inside
switch
making
thedcvolt-
accuracy,
when
ground.
meter
the
source
pick-up
capacity
will be
capa50
ohms
should
voltages
generated
2
MHz
range.
resistor,
scale
is
pure
sine
measured
spurious
from
Table
3-1.
to
the
the
to
is
indi-
of
pF
be
limit
the
3-1
section
m
Mode1403B
.Ull
lilt
FUNCTION:
CD
battery
position; it
Cadmium
When in
should
scale,
BATT. CHARGE: Glows when
CD
connectedtoanACsource
switch
3-2
Three-position
charge
when
applies
batteriestothe
the
BATT.
read
above
whichisequivalentto24
turnedtotheONposition.
the
27. 5
TESf
2.4
voltsonthe
switch
switchisin
volts
from
Mode1403B
position,
Vdcatthe
instrument
with
the
Figure
checks
the
ON
the
Nickel-
circuitry.
the
meter
"0-3"
meter
battery.
FUNCTION
3-1.
is
Front
Panel
Fluorescent
is
on.
RANGE:
volts
INPUT: Connect voltagetobe
CD
these
Description
Iooicator:
selects
rms
full
terminals.
range
scale
Glows when
from
in a 1, 3,10sequence.
0.001
measured
instrument
voltto300
to
Model403B
Section m
o Select
CD
range
2/3ofthe
highest
Connect voltagetobe
terminals
ed
degreeofaccuracy).
black
terminal
----NOTE----The
is
connectedtochassis
For
chassis
grounded
grounded
4058-A-IIIZA
which
meter
(red
outer
voltage
givesareadinginthe
scale
terminal
negative).
black
measurements
ground, connect
black
black
(This
will
insure
measuredatthe
positive
ground
terminaltothe
terminal.
and
terminal
ground.
at
the
un-
Figure
upper
the
INPUT
unground-
3-2.
Voltage
Set FUNCTION
panel
meter
2.4
volts
If
less
charging.
charging
Set FUNCTION
knob will glow, and
for
voltage
When
the
power
ON,
the
dicating
Measurements
switchtoBATT.
reading
(correspondsto24
than
2.4
RefertoParagraph
instructions.
measurement.
instrumentisconnectedtoan
source
BATT. CHARGE
that
the
should be
volts,
the
switchtoON;
the
instrumentisready
and
the
FUNCTION switchisto
batteryisbeing
greater
voltsatbattery).
battery
3-7
lamp
lamp
will glow,
TEsr;
than
needs
for
battery
function
charged.
front
re-
AC
in-
3-3
Section
Table
ill
Table
3-2.
3-1.
EffectofHarmonics
Voltage
Measurements
on Model 403B
Examples
Measurements
of Voltage and DB
Model403B
Input Voltage
Characteristics
Fundamental
Fundamental
2nd
harmonic
Fundamental
2nd
harmonic
Fundamental
2nd
harmonic
Fundamental
3rd
harmonic
Fundamental
3rd
harmonic
Fundamental
3rd
harmonic
3-20.
This
average
tableisa
responding
canbeseeninthe
a
badly
+0, -2%
3-21.
3-22.
in
the
The
dB
distorted
error).
DECIBEL
Measurementsintermsofdecibels
the
same
wayasvoltage
indicationisreadonthedBscale
decibel
scale
levelisthe
indication
True
Value
= 100 100 100
+10%
100.5
+20%
102 100 - 102
+50%
112
+10%
100.5
+20%
102
+50%
112
general
rms
calibrated
table,
signal
errors
(e. g.;
MEASUREMENTS.
algebraic
andDBVOLTS (RANGE)
RMS
Value
100 - 110
one and
voltmeter.
are
small
20%
2nd
measurements
(-12to+2
sumofthe
Indicated
by 403B
100
96 - 104
94 - 108
90 - 116
appliestoany
even
are
with
gives
made
harmonic
except
dB).
meter
position.
As
that
Range
Switch
Voltage
300
10
.003
.001
DB
measurements:
+40
dB
+40
dB
+10
dB
-30
dB
-30
dB
*-50
dB
-60
dB
*NOTE: In
Meter
Scale
measurements:
3
1
3
1
dB
dB
dB
dB
dB
dB
dB
cases
whereameter
below-8dBisobtained,itis
the
next
lower
reading
the
scale
rangeonthe
willbeobtainedinthe
where
highest
tained.
The
same
urements.
lower
1/3
When a
scale,
switchedtothe
readinginthe
situation
exists
readingisobtainedinthe
the
range
next
lower
upper
2/3
Meter
Indicates
1.8
0.44
2.3
.27
+2
dB
-7
dB
-6
dB
o
dB
-8
dB
-9
dB
+1
dB
scale
besttoswitch
instrumentsoa
upper
accuracy
for
voltage
switch
maybeob-
should be
rangetoobtain
scale.
Actual
Level
180
4.4
.0023
.00027
+42
+33
+ 4
-30
-38
-59
-59
reading
portion
meas-
dB
dB
dB
dB
dB
dB
dB
to
of
a
3-23.
To
read
power
watt
into 600
across
(without
by
direct
across
decibels
ohms)
600
ohms.
respecttoreference
reading
the
same
between
obtainedbyreading
cations.
to
3-24.
3-25.
pedances
graph
dBm
ed on
graph.
Table
IMPEDANCE
To
shown in
willbethe
the
For
(For
3-2.)
obtain
other
meter
example,ifthe
+30dBposition,
ohms,
and
in
dBmisobtainedasfollows:
3-4
the
+ 1
(dB-scale
+30
(range
+31
(levelindBasindicatedbymeter)
+ 8
(correction
+39
dBm
directlyindBm,(0dBm=l
the
Comparative
provided
impedance
twoormore
directly
examplesofdB
the
levelindBm
than
600
Figure
algebraic
and
the
the
measurement
indication
switch
mE;asurement
dB
level)
each
measurementismade
value.
measurements
from
the
measurements,
CORRECTION
with
ohms,
the
3-3
may
meter
be'Used.
sumofthe
correction
range
made
ontheDB
scale
indication)
position)
for
90-ohm
must
be
made
measurements
maybeobtained
milli-
The
difference
may
dB-scale
indirefer
GRAPH.
respecttoim-
correction.
The
level
levelasindicat-
shown on
the
switchisat
across
+1,
the
90
level
impedance)
the
be
3-26.
For
the
same
across
in
+ 1
+30
+31
-12.5
10,000
ohms:
(dB-scale
(range
indication)
switch
(levelindBasindicatedbymeter)
(correction
for
ment
conditions,
made
with
position)
10,OOO-ohm
the
measure-
impedance)
+18.5dBm
In
3-27.
3-28.
3-29.
quick
full
scale
3-33.
around
into
the
CURRENT MEASUREMENTS.
CLIP-ON
The
measurement
To
the
Model 403B.
-hp-
with
use
current
PROBE.
Model 456A
of
minimum
the
Model 456A,
carrying
The
current
circuit
probe
Current
from
loading.
simply
wire
and plug
outputis1 mV
Probe
provides
1 rnAto1
clamp
the
the
output
amp
probe
/mA.
Model403B
Section
+20
+15
~
+10
OJ
0
I
Z
0
+5
~
U
W
a:
a:
0
0
u
a:
w
~
W
-5
~
III
-10
-15
-20
-25
I
10
100
IK
10K
lOOK
IMPEDANCE - OHMS
Figure
3-3.
Model 403B
Impedance
Correction
Graph
3-5
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