BK Precision 2160A, 1541D User Manual
INSTRUCTION
MANUAL
MANUAL DE INSTRUCCION
MODELS 1541D
and 2160A
MODELOS 1541D & 2160A
40 MHz & 60 MHz DUAL-TRACE OSCILLOSCOPES
40MHz & 60MHz DOBLE LINEA OSCILOSCOPIOS
TEST INSTRUMENT SAFETY
WARNING
Normal use of test equipment exposes you to a certain amount of danger from electrical shock because
testing must often be performed where exposed high voltage is present. An electrical shock causing
10milliampsofcurrenttopassthroughthe heartwillstopmosthumanheartbeats.Voltageaslow as 35 volts
dc or ac rms should be considered dangerous and hazardous since it can produce a lethal current under
certain conditions. Higher voltage poses an even greater threat because such voltage can more easily
produce a lethal current. Your normal work habits should include all accepted practices that will prevent
contact with exposed high voltage, and that will steer current away from your heart in case of accidental
contact with a high voltage. You will significantly reduce the risk factor if you know and observe the
following safety precautions:
1. Don’t expose high voltage needlessly in the equipment under test. Remove housings and covers only when necessary.
Turn off equipment while making test connections in high-voltage circuits. Discharge high-voltage capacitors after
removing power.
2. If possible, familiarize yourself with the equipment being tested and the location of its high voltage points. However,
remember that high voltage may appear at unexpected points in defective equipment.
3. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work surface on which to
place equipment; make certain such surfaces are not damp or wet.
4. Use the time-proven “one hand in the pocket” technique while handling an instrument probe. Be particularly careful to
avoid contacting a nearby metal object that could provide a good ground return path.
5. When using a probe, touch only the insulated portion. Never touch the exposed tip portion.
6. When testing ac powered equipment, remember that ac line voltage is usually present on some power input circuits such
as the on-off switch, fuses, power transformer, etc. any time the equipment is connected to an ac outlet, even if the
equipment is turned off.
7. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the “hot chassis” type.
This includes most recent television receivers and audio equipment. A plastic or wooden cabinet insulates the chassis
toprotect the customer. When the cabinet is removed for servicing, a serious shock hazard exists if the chassis is touched.
Not only does this present a dangerous shock hazard, but damage to test instruments or the equipment under test may
result from connecting the ground lead of most test instruments (including this oscilloscope) to a “hot chassis”. To make
measurements in “hot chassis” equipment, always connect an isolation transformer between the ac outlet and the
equipment under test. The B+K Precision Model TR-110 or 1604A Isolation Transformer, or Model 1653A or 1655A
AC Power Supply is suitable for most applications. To be on the safe side, treat all two wire ac powered equipment as
“hot chassis” unless you are sure it has an isolated chassis or an earth ground chassis.
8. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary
resuscitation) first aid is highly recommended.
Instruction Manual
22820 Savi Ranch Parkway, Yorba Linda, CA 92887
for
+
BK PRECISION
®
Models 1541D
and 2160A
40 MHz and 60 MHz
Dual-Trace Oscilloscopes
©2000 B+K Precision Corp.
This symbol on oscilloscope means “refer to instruction manual
for further precautionary information”. This symbol appears in the
manual where the corresponding information is given.
+
®
TABLE OF CONTENTS
Page Page
TEST INSTRUMENT SAFETY . . . . . . inside front cover
FEATURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
CONTROLS AND INDICATORS . . . . . . . . . . . . . . . . . . 7
General Function Controls . . . . . . . . . . . . . . . . . . . . . . 7
Vertical Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Horizontal Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Triggering Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Rear Panel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 10
OPERATING INSTRUCTIONS. . . . . . . . . . . . . . . . . . . 11
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Equipment Protection Precautions. . . . . . . . . . . . . . . 11
Operating Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Initial Starting Procedure . . . . . . . . . . . . . . . . . . . . . . 12
Single Trace Display . . . . . . . . . . . . . . . . . . . . . . . . . 12
Dual Trace Display. . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Triggering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Magnified Sweep Operation . . . . . . . . . . . . . . . . . . . 15
OPERATING INSTRUCTIONS (Continued)
X−Y Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Video Signal Observation . . . . . . . . . . . . . . . . . . . . . 15
Applications Guidebook . . . . . . . . . . . . . . . . . . . . . . 15
Delayed Sweep Operation. . . . . . . . . . . . . . . . . . . . . 15
Component Test Operation . . . . . . . . . . . . . . . . . . . . 16
MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Line Voltage Selection. . . . . . . . . . . . . . . . . . . . . . . . 20
Periodic Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . 20
Calibration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Instrument Repair Service. . . . . . . . . . . . . . . . . . . . . 21
APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Important Considerations for Rise Time and
Fall Time Measurements . . . . . . . . . . . . . . . . . . . . 22
Service Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SPANISH MANUAL . . . . . . . . . . . . . . . . . . . . . . . . . 25
“Guidebook To Oscilloscopes”
Availability . . . . . . . . . . . . . . . . . . . . . inside back cover
2
FEATURES
LOW COST ,HIGH PERFORMANCE
B+K Precision’s 40 MHz and 60 MHz oscilloscopes are
among the lowest cost in the industry, yet offer high
performance and features not found on many competitors’
oscilloscopes. Model 2160A includes a built-in component
tester,which is an excellent tool for in-circuit troubleshooting. These oscilloscopes are built by and backed by B+K
Precision, a compnay that has been selling reliable, durable,
value priced test instruments for over 50 years.
CRT FEATURES
Rectangular CRT
Rectangular CRTwith large 8 x 10 centimeter viewing
area. On Model 2160A, graticule is equipped with
variable scale illumination.
Convenience
Tracerotation electrically adjustable from front panel.
0%, 10%, 90%, and 100% markers for rise time measurements.
DUAL TRACE FEATURES
Dual Trace
Models2160A and 1541D eachhavetwo verticalinput
channels for displaying two waveforms simultaneously. Selectable single trace (either CH 1 or CH 2) or
dual trace. Alternate or chop sweep selectable at all
sweep rates.
Sum and Difference Capability
Permits algebraic addition or subtraction of channel 1
and channel 2 waveforms, displayed as a single trace.
Useful for differentialvoltageand distortion measurements.
HIGH FREQUENCY FEATURES
Wide Bandwidth
Conservatively-rated −3 dB bandwidth is dc to 60
MHz for Model 2160A and dc to 40 MHz for Model
1541D.
Fast Rise Time
Rise time is less than 5.8 ns for Model 2160A and
8.8 ns for Model 1541D.
Fast Sweep
Maximum sweep speed of 10 ns/div (with X10 MAG)
assures high frequencies and short-duration pulses are
displayed with high resolution.
VERTICAL FEATURES
High Sensitivity
5 mV/div sensitivityfor full bandwidth. High-sensitivity 1 mV/div and 2 mV/div using PULL X5 gain
control.
Calibrated VoltageMeasurements
Accurate voltage measurements (±3%) on 10 calibrated ranges from 5 mV/div to 5 V/ div. Vertical gain
fully adjustable between calibrated ranges.
SWEEP FEATURES
Calibrated Time Measurements
Accurate (±3%) time measurements. The main sweep
has 23 calibrated ranges from 2 S/div to 0.1 µS/div.
The delayed sweep on the Model 2160A has 23 calibrated ranges from 2 S/div to 0.1 µS/div. Sweep time
is fully adjustable between calibrated ranges.
X10 Sweep Magnification
Allows closer examination of waveforms, increases
maximum sweep rate to 10 nS/div.
DUAL TIME BASE FEATURES (Model 2160A)
Dual Sweep Generators
Main sweep gives normal waveform display, delayed
sweepmay beoperatedat fastersweepspeed toexpand
a portion of the waveform.
Four Sweep Modes
Choice of main sweep only, delayed sweep only,
main sweep and delayed sweep sh arin g the tr ace
(percentage of mai n/d elaye d sweep adjustable), or
X−Y.
Adjustable Start Of Delayed Sweep
DELAY TIME POSition control allows adjustment of
delayed sweep starting point.
TRIGGERING FEATURES
Two Trigger Modes
Selectable normal (triggered) or automatic sweep
modes.
Triggered Sweep
Sweep remains at rest unless adequate trigger signal is
applied. Fully adjustable trigger level and (+) or (−)
slope.
3
FEATURES
AUTO Sweep
Selectable AUTO sweep provides sweep without trigger input, automatically reverts to triggered sweep
operation when adequate trigger is applied.
Five TriggerSources
Five trigger source selections, including CH 1, CH 2,
alternate, EXT, and LINE.
Video Sync
Frame(TV V) or Line (TV H) triggering selectablefor
observingcomposite video waveforms.TV-Hposition
can also be used as low frequency reject and TV-V
position can be used as high frequency reject.
Variable Holdoff
Trigger inhibit period after end of sweep adjustable.
Permits stable observation of complex pulse trains.
OTHER FEATURES
X−Y Operation
Channel 1 can be applied as horizontal deflection
(X-axis) while channel 2 provides vertical deflection
(Y-axis).
Built-in Probe Adjust Square Wave
A 2 V p-p, 1 kHz square wave generator permits probe
compensation adjustment.
Component TestFunction (Model 2160A)
Built-inX−Ytypecomponent tester appliesfixedlevel
ac signal to components for display of signature on
CRT.
Channel 2 (Y) Output (Model 2160A)
A buffered 50Ω output of the channel 2 signal is
available at the rear panel for driving a frequency
counter or other instruments. The output is 50 mV/div
(nominal) into 50Ω.
Z-Axis Input (Model 2160A)
Rear panel Z-Axis input allows intensity modulation.
Supplied With TwoProbes
4
SPECIFICATIONS
CRT
Type: 6-inch rectangular with integral graticule,
P31 phosphor.
DisplayArea: 8 x 10 div (1 div = 1 cm).
AcceleratingVoltage: 12 kV.
Phosphor:P31.
Trace Rotation: Electrical, front panel adjustable.
Scale Illumination: Continuously variable (Model 2160A).
Beam Finder (Model 2160A).
VERTICAL AMPLIFIERS (CH 1 and CH 2)
Sensitivity: 5 mV/div to 5 V/div, 1 mv/div to 1 V/div at
X5 MAG.
Attenuator:10 calibrated steps in 1-2-5 sequence.Vernier
control provides fully adjustable sensitivity between
steps; range 1/1 to at least 1/3.
Accuracy:±3%, 5 mV to 5 V/div; 5%, at X5 MAG.
Input Resistance:1MΩ±2%.
Input Capacitance: 25 pF ±10 pF.
Frequency Response:
5 mV/div to 5 V/div:
DC to 60 MHz (−3 dB), Model 2160A
DC to 40 MHz (−3 dB), Model 1541D.
X5 MAG:
DC to 15 MHz (−3 dB), Model 2160A
DC to 10 MHz (−3 dB), Model 1541D.
Rise Time:
5.8 nS, Model 2160A
8.8 nS, Model 1541D.
Overshoot:Less than 5%.
Operating Modes:
CH 1: CH 1, single trace.
CH 2: CH 2, single trace.
DUAL: CH 1 and CH 2, dual trace.
Alternate or Chop selectable at
any sweep rate.
ADD: Algebraic sum of CH 1 + CH 2.
Chop Frequency:Approximately 500 kHz.
PolarityReversal:CH 2 invert.
HORIZONTAL AMPLIFIER
(Input through channel 1 input)
X−Y mode:
CH 1 = X axis.
CH 2 = Y axis.
Sensitivity: Same as verticalchannel 2.
Input Impedance: Same as vertical channel 2.
Frequency Response:
DC to 1 MHz (−3 dB).
X-Y Phase Difference: 3° or less at 50 kHz.
MaximumInputVoltage: Same as vertical channel 1.
SWEEP SYSTEM
Operating Modes:
Model 2160A: Main, Mix (both main and delayed
sweep displayed), Delay (only delayed sweep
displayed), X−Y.
Model 1541D: Main only.
Main Time Base: 0.1 µS/div to 2.0 S/div in 1-2-5
sequence,23 steps. Vernier control provides fully
adjustablesweep time between steps.
DelayedTime Base (Model 2160A only): 0.1 µS/divto
2.0 S/div in 1-2-5 sequence, 23 steps.
Accuracy:±3%.
Sweep Magnification: X10 ±10%.
Holdoff: Continuously adjustable for main time base from
NORM to 5 times normal.
Delay Time Position: Control sets percentage of display
that is devotedto main and delayed sweep.
Delay Jitter: 1/10,000 of full scale sweep time.
TRIGGERING
Trigger Modes:
AUTO (free run), NORM, TV-V, TV-H.
Trigger Source:
CH 1, CH 2, Alternate, EXT,LINE.
Slope:
(+) or (–).
MaximumInput Voltage: 400 V (dc + ac peak).
5
SPECIFICATIONS
NOTE:
Specifications and information
are
subject to change without notice.
Please visit
Trigger Coupling:
AUTO: Sweep free-runs in absence of
suitable trigger signal.
NORM: Sweep triggered only by adequate
trigger signal.
TV-V: Video vertical sync pulses are
selected. Also usable for high
frequency reject.
TV-H: Video horizontal sync pulses are
selected. Also usable for low
frequency reject.
Trigger Sensitivity:
Auto: 1.5 div (internal)
≥0.5 Vp-p (external)
100 Hz – 60 MHz (2160A)
100 Hz – 40 MHz (1541D)
Norm: 1.5 div (internal)
≥0.5 Vp-p (external)
100 Hz – 60 MHz (2160A)
DC – 40 MHz (1541D)
TV-V: 1.0 div (internal)
≥0.5 Vp-p (external)
DC – 1 kHz
TV-H: 1.0 div (internal)
≥0.5 Vp-p (external)
1 kHz – 100 kHz
MaximumExternalTriggerVoltage: 300 V (dc + ac
peak).
COMPONENTTESTER (Model 2160A)
ComponentsTested: Resistors, capacitors, inductors, and
semiconductors.
Test Voltage: 6 V rms maximum (open).
Test Current: 11 mA maximum (shorted).
Test Frequency:Line frequency (60 Hz in USA).
OTHER SPECIFICATIONS
Cal/ProbeCompensationVoltage: 2 V p-p ±3% square
wave,1 kHz nominal.
CH 2 (Y) Output (Model 2160A):
Output Voltage: 50 mV/div (nominal into 50 ohm
load).
Output Impedance: Approximately 50 ohms.
Frequency Response:20 Hz to 30 MHz, −3 dB.
IntensityModulation (Model 2160A)
Input Signal: TTL level, intensity increasing with
more positive levels, decreased intensity with more
negative levels.
Input Impedance: Approximately 50 kΩ.
Usable Frequency Range: DC to 5 MHz.
Maximum Input Voltage: 30 V (dc + ac peak).
Power Requirements: 100–130 VACor 200–260 VAC,
50/60 Hz, 38 watts.
Dimensions (H 3 W3 D):
5.2″ 3 12.8″ 3 15.7″
(132 3 324 3 398 mm).
Weight: 16.8 lbs (7.6 kg).
Environment:
Within Specified Accuracy: +10° to +35° C, 10–80%
relative humidity.
Full Operation: 0° to +50° C, 10–80% relative
humidity.
Storage: −30° to +70° C, 10–90% relative humidity.
ACCESSORIES SUPPLIED:
Two Switchable X1/X10 Probes.
Instruction Manual.
AC Line Cord.
www.bkprecision.com for the most current product information.
6
CONTROLS AND INDICATORS
18
17
6
1
5
2
4
33
32
31
30
28
27
26
25
24
34
13
Fig. 1. Model 2160A Controls and Indicators.
GENERAL FUNCTION CONTROLS
1. ON Indicator. Lights when oscilloscope is “on”.
2. 2160A Only. POWER/Scale ILLUMination Control. Clockwise rotation from OFF position turns os-
cilloscope “on”. Further clockwise rotation increases
amount of graticule illumination.
3. 1541D Only. POWER Pushbutton. Turns oscilloscope “on” and “off”.
4. INTENSITY Control. Adjusts brightness of trace.
5. TRACE ROTATION Control. Adjusts to maintain
trace at a horizontal position.
6. FOCUS Control. Adjusts trace focus.
7. 2160A Only. COMPonent TEST Pushbutton. With
pushbutton set to “in” position, Component Test mode
is enabled. Normal scope operation is enabled with
pushbutton in “out” position.
8. 2160A Only. COMPonent TEST Jack. “Banana”type HI-side input jack for connection to component
in Component Test operating mode.
9. GND Terminal. Oscilloscope chassis ground
jack, and earth ground via three-wire ac power cord.
On Model 2160A, also serves as LO-side Component
Test jack.
14
15
7
8
16
10
12
11
19
20
9
21
22
23
10. CAL Terminal. Terminal provides 2 V p-p, 1 kHz
(nominal) square wave signal. This signal is useful for
checking probe compensation adjustment, as well as
providing a rough check of vertical calibration.
11. 2160AOnly.BEAM FIND Pushbutton. Momentary-
contact pushbutton speeds setup of trace positioning
by bringing the beam into graticule area; operates
independently of other display controls.
VERTICAL CONTROLS
12. VERTical MODE Switch. Selects vertical display
mode. Four-position lever switch with the following
positions:
CH1:
Displays the channel 1 signal by itself.
CH2/X-Y:
CH2: displays the channel 2 signal by itself.
X-Y: used in conjunction with the X-Y control and
Trigger SOURCE switch to enable X-Y display
mode.
DUAL:
Displays the channel 1 and channel 2 signals simultaneously. Dual-trace mode may be either alternate
or chop ped sweep; see the description under
HOLDOFF/PULL CHOP control.
7
CONTROLS AND INDICATORS
18
17
6
4
1
5
3
33
32
31
30
28
27
26
33
14
13
Fig. 2. Model 1541D Controls and Indicators.
ADD:
The inputs from channel 1 and channel 2 are
summed and displayed as a single signal. If the
Channel 2 POSition/PULL INVert control is
pulled out, the input from channel 2 is subtracted
from channel 1 and the difference is displayed as a
single signal.
13. CH1 AC-GND-DC Switch. Three-position lever
switch with the following positions:
AC:
Channel 1 input signal is capacitively coupled; dc
component is blocked.
GND:
Opens signal path and grounds input to vertical
amplifier. This provides a zero-volt base line, the
position of which can be used as a reference when
performing dc measurements.
DC:
Direct coupling of channel 1 input signal; both ac
and dc components of signal produce vertical deflection.
14. CH1 (X) Input Jack. Vertical input for channel 1.
X-axis input for X-Y operation.
15. CH1 (X) VOLTS/DIV Control. Vertical attenuator
for channel 1. Provides step adjustment of vertical
sensitivity. When channel 1 VARiable control is set
to CAL, vertical sensitivity is calibrated in 10 steps
from 5 mV/div to 5 V/div in a 1-2-5 sequence. When
15
16
12
10
19
9
20
21
22
34
the X-Y mode of operation is selected, this control
provides step adjustment of X-axis sensitivity.
16. CH1 VARiable/PULL X5 MAG Control:
VARiable:
Rotation provides vernier adjustment of channel 1
vertical sensitivity. In the fully-clockwise (CAL)
position, the vertical attenuator is calibrated. Counterclockwise rotation decreases gain sensitivity. In
X-Y operation, this control becomes the vernier
X-axis sensitivity control.
PULL X5 MAG:
When pulled out, increases vertical sensitivity by a
factor of five. Effectively provides two extra sensitivity settings: 2 mV/div and 1 mV/div. In X-Y
mode, increases X-sensitivity by a factor of five.
17. CH1 POSition/PULL ALT TRIGger Control:
POSition:
Adjusts vertical position of channel 1 trace.
PULL ALT:
Used in conjunction with the Trigger SOURCE
switch to activate alternate triggering. See the description under the Trigger SOURCE switch.
18. CH2 POSition/PULL INVert Control:
POSition:
Adjusts vertical position of channel 2 trace. In X-Y
operation, rotation adjusts vertical position of X-Y
display.
8
CONTROLS AND INDICATORS
PULL INVert:
When pushed in, the polarity of the channel 2 signal
is normal. When pulled out, the polarity of the
channel 2 signal is reversed, thus inverting the
waveform.
19. CH2 VOLTS/DIV Control. Vertical attenuator for
channel 2. Provides step adjustment of vertical sensitivity. When channel 2 VARiable control is set to
CAL, vertical sensitivity is calibrated in 10 steps from
5 mV/div to 5 V/div in a 1-2-5 sequence. When the
X-Y mode of operation is selected, this control provides step adjustment of Y-axis sensitivity.
20. CH2 VARiable/PULL X5 MAG Control:
VARiable:
Rotation provides vernier adjustment of channel 2
vertical sensitivity. In the fully-clockwise (CAL)
position, the vertical attenuator is calibrated. Counterclockwise rotation decreases gain sensitivity. In
X-Y operation, this control becomes the vernier
Y-axis sensitivity control.
PULL X5 MAG:
When pulled out, increases vertical sensitivity by a
factor of five. Effectively provides two extra sensitivity settings: 2 mV/div and 1 mV/div. In X-Y
mode, increases Y-sensitivity by a factor of five.
21. CH2 (Y) Input Jack. Vertical input for channel 2.
Y-axis input for X-Y operation.
22. CH2 AC-GND-DC Switch. Three-position lever
switch with the following positions:
AC:
Channel 2 input signal is capacitively coupled; dc
component is blocked.
GND:
Opens signal path and grounds input to vertical
amplifier. This provides a zero-volt base line, the
position of which can be used as a reference when
performing dc measurements.
DC:
Direct coupling of channel 2 input signal; both ac
and dc components of signal produce vertical deflection.
HORIZONTAL CONTROLS
23. Main Time Base TIME/DIV Control. Provides step
selection of sweep rate for the main time base. When
theVARiable Sweep control isset to CAL, sweep rate
iscalibrated. This controlhas23 steps, from0.1 µS/div
to 2 S/div, in a 1-2-5 sequence.
24. 2160A Only. DELAY Time Base TIME/DIV Control. Provides step selection of sweep rate for delayed
sweep time base. This control has 23 steps, from 0.1
µS/div to 2 S/div, in a 1-2-5 sequence.
25. 2160A Only. DELAY TIMEPOSition Control. Sets
starting point of delayed sweep. Clockwise rotation
causes delayed sweep to begin earlier.
26. VARiable Sweep Control. Rotation of control is ver-
nier adjustment for sweep rate. In fully clockwise
(CAL) position, sweep rate is calibrated. On the
Model 2160A, this control is the vernier adjustment
for both the main and delayed time bases.
27. POSition/PULL X10 MAG Control.
POSition:
Horizontal (X) position control.
PULL X10 MAG:
Selects ten times sweep magnification when pulled
out, normal when pushed in. Increases maximum
sweep rate to 10 nS/div.
28. 2160A Only. Sweep Mode Switch. Selects sweep
(horizontal) mode. Four-position rotary switch with
the following positions:
MAIN:
Only the main sweep operates, with the delayed
sweep inactive.
MIX:
The main and delayed sweep share a single trace;
main sweep occupies the left portion of the display;
delayed sweep occupies the right portion of the
display. The DELAY TIME POSition control de-
termines the percentage of display that is main
sweep and the percentage of display that is delayed
sweep (main sweep is usually brighter than the
delayed sweep). Delayed sweep speed cannot be
slower than main sweep speed.
DELAY:
Only delayed sweep operates, while main sweep
stays inactive. DELAY TIME POSition control
determines the starting point of the delayed sweep.
X-Y:
Used with the VERTical MODE switch and Trigger SOURCE switch to select X- Y operating
mode. The channel 1 input becomes the X-axis and
the channel 2 input becomes the Y-axis. Trigger
source and coupling are disabled in this mode.
29. 1541D Only. X-Y Switch. Used with the VERTical
MODE switch and Trigger SOURCE switch to se-
lect X-Y operating mode. The channel 1 input becomes the X-axis and the channel 2 input becomes the
Y-axis. Trigger source and coupling are disabled in
this mode.
9
CONTROLS AND INDICATORS
TRIGGERING CONTROLS
30. HOLDOFF/PULL CHOP Control.
HOLDOFF:
Rotation adjusts holdoff time (trigger inhibit period
beyond sweep duration). When control is rotated
fully counterclockwise, the holdoff period is MIN-
inum (normal). The holdoff period increases progressively with clockwise rotation.
PULL CHOP:
When this switch is pulled out in the dual-trace
mode, the channel 1 and channel 2 sweeps are
chopped and displayed simultaneously (normally
used at slower sweep speeds). When it is pushed in,
the two sweeps are alternately displayed, one after
the other (normally used at higher sweep speeds).
31. Trigger SOURCE Switch. Selects source of sweep
trigger. Four-position lever switch with the following
positions:
CH1/X-Y/ALT
CH1:
Causes the channel 1 input signal to become the
sweep trigger, regardless of the VERTical
MODE switch setting.
X-Y:
Used with two other switches to enable the X-Y
mode — see the Operating Instructions under
“XY Operation”.
ALT:
Used with the channel 1 POSition/PULL
ALTernate TRIGger control to enable alternate
triggering. Alternate triggering, used in dualtrace mode, permits each waveform viewed to
become its own trigger source.
CH2:
The channel 2 signal becomes the sweep trigger,
regardless of the VERTicalMODE switch setting.
LINE:
Signal derived from input line voltage (50/60 Hz)
becomes trigger.
EXT:
Signal from EXTernal TRIGger jack becomes
sweep trigger.
32. Trigger COUPLING Switch. Selects trigger cou-
pling. Four-position lever switch with the following
positions:
AUTO:
Selectsautomatic triggeringmode.In this mode,the
oscilloscope generates sweep (free runs) in absence
of an adequate trigger; it automatically reverts to
triggeredsweepoperation when anadequate trigger
signal is present. On the Model 2160A, automatic
triggering is applicable to both the main sweep and
delayed sweep.
NORM:
Selects normal triggered sweep operation. A sweep
is generated only when an adequate trigger signal is
present.
TV-V:
Used for triggering from television vertical sync
pulses. Also serves as lo-pass/dc (high frequency
reject) trigger coupling.
TV-H:
Used for triggering from television horizontal sync
pulses.Also servesashi-pass (low frequencyreject)
trigger coupling.
33. TRIGger LEVEL/PULL (-) SLOPE Control.
TRIGger LEVEL:
Trigger level adjustment; determines the point on
the triggering waveform where the sweep is triggered. Rotation in the (-) direction (counterclockwise) s elects more negative triggering point;
rotation in the (+) direction (clockwise) selects
more positive triggering point.
PULL (—) SLOPE:
Two-position push-pull switch. The “in” position
selectsa positive-going slope and the “out” position
selectsa negative-goingslopeastriggering point for
main sweep.
34. EXTernal TRIGger Jack. External trigger input for
single- and dual-trace operation.
REAR PANEL CONTROLS (not shown)
35. Fuse Holder/Line Voltage Selector. Contains fuse
and selects line voltage.
36. Power Cord Receptacle.
37. 2160A Only. CH 2 (Y) SIGNAL OUTPUT Jack.
Output terminal where sample of channel 2 signal is
available.Amplitude of output is nominally 50mVper
division of vertical deflection seen on CRT when
terminated into 50 Ω. Output impedance is 50 Ω.
38. 2160A Only. Z-Axis Input Jack. Input jack for intensity modulation of CRT electron beam. TTL compatible (5 V p-p sensitivity). Positive levels increase
intensity.
39. Handle/Tilt Stand.
40. Feet/Cord Wrap.
10
OPERATING INSTRUCTIONS
NOTE
All operating instructions in this chapter
apply equally to both Models 2160A and
1541D,exceptfor the sectionson“Delayed
Sweep Operation” and “Component Test”,
which apply only to the Model 2160A.
Other differences are noted when necessary.
SAFETY PRECAUTIONS
WARNING
The following precautions must be observed to help prevent electric shock.
1. When the oscilloscope is used to make measurements
in equipment that contains high voltage, there is always acertainamountofdangerfromelectricalshock.
The person using the oscilloscope in such conditions
should be a qualified electronics technician or otherwise trained and qualified to work in such circumstances. Observe the TEST INSTRUMENT SAFETY
recommendations listed on the inside front cover of
this manual.
2. Donotoperate this oscilloscope with the caseremoved
unless you are a qualified service technician. High
voltage up to 12,000 volts is present when the unit is
operating with the case removed.
3. The ground wire of the 3-wire ac power plug places
the chassis and housing of the oscilloscope at earth
ground. Use only a 3-wire outlet, and do not attempt
to defeat the ground wire connection or float the oscilloscope; to do so may pose a great safety hazard.
4. Specialprecautions are required to measureorobserve
line voltage waveforms with any oscilloscope. Use the
following procedure:
a. Do not connect the ground clip of the probe to
either side of the line. The clip is already at earth
ground and touching it to the hot side of the line
may “weld” or “disintegrate” the probe tip and
cause possible injury, plus possible damage to the
scope or probe.
b. Insert the probe tip into one side of the line voltage
receptacle, then the other. One side of the receptacleshould be “hot” and producethe waveform.The
other side of the receptacle is the ac return and no
waveform should result.
EQUIPMENT PROTECTION
PRECAUTIONS
Thefollowing precautionswill help avoid
damage to the oscilloscope.
1. Never allow a small spot of high brilliance to remain
stationary on the screen for more than a few seconds.
The screen may become permanently burned. A spot
will occur when the scope is set up for X−Y operation
and no signal is applied. Either reduce the intensity so
the spot is barely visible, apply signal, orswitch back
to normal sweep operation. It is also advisable to use
low intensity with AUTO triggering and no signal
applied for long periods. A high intensity trace at the
same position could cause a line to become permanently burned onto the screen.
2. Do not obstruct the ventilating holes in the case, as this
will increase the scope’s internal temperature.
3. Excessive voltage applied to the input jacks may damage the oscilloscope. The maximum ratings of the
inputs are as follows:
CH 1 and CH 2:
400 V dc + ac peak.
EXT TRIG:
300 V dc + ac peak.
Z-AXIS INPUT (Model 2160A):
30 V ( dc and ac peak).
4. Always connect a cable from the ground terminal of
the oscilloscope to the chassis of the equipment under
test. Without this precaution, the entire current for the
equipment under test may be drawn through the probe
clip leads under certain circumstances. Such conditionscould also pose a safety hazard,whichthe ground
cable will prevent.
5. The probe ground clips are at oscilloscope and earth
ground and should be connected only to the earth
ground or isolated common of the equipment under
test. To measure with respect to any point other than
the common, use CH 2 – CH 1 subtract operation
(ADD mode and INV 1), with the channel 2 probe to
the point of measurement and the channel 1 probe to
the point of reference. Use this method even if the
reference point is a dc voltage with no signal.
11
OPERATING INSTRUCTIONS
OPERATING TIPS
The following recommendations will help obtain the best
performance from the oscilloscope.
1. Always use the probe ground clips for best results,
attached to a circuit ground point near the point of
measurement.Do not rely solely on an externalground
wire in lieu of the probe ground clips as undesired
signals may be introduced.
2. Avoid the following operating conditions:
a. Direct sunlight.
b. High temperature and humidity.
c. Mechanical vibration.
d. Electricalnoise and strong magnetic fields, such as
near large motors, power supplies, transformers,
etc.
3. Occasionally check trace rotation, probe compensation,and calibration accuracyofthe oscilloscope using
the procedures found in the MAINTENANCE section
of this manual.
4. Terminate the output of a signal generator into its
characteristic impedance to minimize ringing, especially if the signal has fast edges such as square waves
or pulses. For example, the typical 50 Ω output of a
square wave generator should be terminated into an
external 50 Ω terminating load and connected to the
oscilloscope with 50 Ω coaxial cable.
5. Probe compensation adjustment matches the probe to
the input of the scope. For best results, compensation
should be adjusted initially, then the same probe alwaysusedwith the same channel. Probecompensation
should be readjusted when a probe from a different
oscilloscope is used.
INITIAL STARTING PROCEDURE
Until you familiarize yourself with the use of all controls,
the settings given here can be used as a reference point to
obtain a trace on the CRT in preparation for waveform
observation.
1. Set these controls as follows:
On both models:
VERTical MODE to CH1.
CH1AC/GND/DC to GND.
Trigger COUPLING to AUTO.
Trigger SOURCE to CH1.
All POSition controls and INTENSITY control centered (pointers facing up).
Main Time Base control to 1 mS/div.
On the Model 2160A:
Sweep Mode switch to MAIN.
2. Press the red POWER pushbutton (Model 1541D), or
rotate the POWER control clockwise away from
“OFF” (Model 2160A).
3. A trace should appear on the CRT. Adjust the trace
brightness with the INTENSITY control, and the
trace sharpness with the FOCUS control.
NOTE
On the Model 2160A, you can use the
BEAM FINDER pushbutton to locate a
trace that has been moved off the screen by
the POSition controls. When the button is
pushed, a compressed version of the trace
is brought into view which indicates the
location of the trace.
SINGLE TRACEDISPLAY
Either channel 1 or channel 2 maybe used for single-trace
operation. To observe a waveform on channel 1:
1. Perform the steps of the “Initial Starting Procedure”.
2. Connect the probe to the CH 1 (X) input jack.
3. Connect the probe ground clip to the chassis or common of the equipment under test. Connect the probe
tip to the point of measurement.
4. Move the CH1 AC/GND/DC switch out of the GND
position to either DC or AC.
5. If no waveforms appear, increase the sensitivity by
turning the CH 1 VOLTS/DIV control clockwise to a
position that gives 2 to 6 divisions vertical deflection.
6. Position the waveform vertically as desired using the
CH1 POSition control.
7. Thedisplay on the CRT maybeunsynchronized.Refer
to the “Triggering” paragraphs in this section for procedures on setting triggering and sweep time controls
to obtain a stable display showing the desired number
of waveforms.
DUAL TRACE DISPLAY
In observing simultaneous waveforms on channel 1 and
2, the waveforms are usually related in frequency, or one of
the waveforms is synchronized to the other, although the
basic frequencies are different. To observe two such related
waveforms simultaneously, perform the following:
1. Connect probes to both the CH 1 (X) and CH 2 (Y)
input jacks.
2. Connect the ground clips of the probes to the chassis
or common of the equipment under test. Connect the
tips of the probes to the two points in the circuit where
waveforms are to be measured.
12
OPERATING INSTRUCTIONS
3. To view both waveforms simultaneously, set the
VERTical MODE switch to DUAL and select either
ALT (alternate) or CHOP with the PULL CHOP
switch.
4. In the ALT sweep mode (PULL CHOP switch
pushed in), one sweep displays the channel 1 signal
and the next sweep displays the channel 2 signal in an
alternating sequence. Alternate sweep is normally
used for viewing high-frequency or high-speed waveforms at sweep times of 1 ms/div and faster, but may
be selected at any sweep time.
5. In the CHOP sweep mode (PULL CHOP switch
pulled out), the sweep is chopped (switched) between
channel 1 and channel 2. Using CHOP, one channel
does not have to “wait” for a complete swept display
of the other channel. Therefore, portions of both channel’swaveformsaredisplayedwith the phase relationship between the two waveforms unaltered. Chop
sweep is normally used for low-frequency or lowspeed waveforms at sweep times of 1 ms/div and
slower; or where the phase relationship between channel 1 and channel 2 requires measurement.
If chop sweep is used at sweep times of 0.2 ms/div and
faster, the chop rate becomes a significant portion of
the sweep and may become visible in the displayed
waveform. However, you may select chop sweep at
any sweep time for special applications.
6. Adjust the channel 1 and 2
▲
POSition controls to
▼
place the channel 1 trace above the channel 2 trace.
7. Set the CH 1 and CH 2 VOLTS/DIV controls to a
position that gives 2 to 3 divisions of vertical deflection for each trace. If the display on the screen is
unsynchronized, refer to the “Triggering” paragraphs
in this section of the manual for procedures for setting
triggering and sweep time controls to obtain a stable
display showing the desired number of waveforms.
8. WhentheVERTicalMODE switch is set to ADD, the
algebraic sum of CH 1 + CH 2 is displayed as a single
trace. When the PULL INV switch is pulled out, the
algebraic difference of CH 1 – CH 2 is displayed.
9. Iftwowaveformshavenophaseorfrequencyrelationship, there is seldom reason to observe both waveforms simultaneously. However, these oscilloscopes
do permit the simultaneous viewing of two such unrelated waveforms, using alternate triggering. Refer to
the paragraphs on “Triggering - Trigger SOURCE
Switch”, for details on alternate triggering.
TRIGGERING
The Models 2160A and 1541D Oscilloscopes provide
versatility in sync triggering for ability to obtain a stable,
jitter-free display in single-trace, or dual-trace operation.
The proper settings depend upon the type of waveforms
being observed and the type of measurement desired. An
explanation of the various controls which affect synchronization is given to help you select the proper setting over a
wide range of conditions.
Trigger COUPLING Switch
1. In the AUTO position, automatic sweep operation is
selected. In automatic sweep operation, the sweep
generator free-runs to generate a sweep without a
trigger signal. However, it automatically switches to
triggered sweep operation if an acceptable trigger
source signal is present. The AUTO position is handy
when first setting up the scope to observe a waveform;
itprovides sweepforwaveform observationuntilother
controls can be properly set. Once the controls are set,
operation is often switched back to the normal triggering mode, since it is more sensitive. Automatic sweep
must be used for dc measurements and signals of such
low amplitude that they will not trigger the sweep.
2. The NORM position provides normal triggered
sweep operation. The sweep remains at rest until the
selected trigger source signal crosses the threshold
level set by the TRIG LEVEL control. The trigger
causes one sweep to be generated, after which the
sweep again remains at rest until triggered. In the
normal triggering mode, there will be no trace unless
an adequate trigger signal is present. In the ALT
VERTICAL MODE of dual trace operation with the
SOURCE switch also set to ALT, there will be no
trace unless both channel 1 and channel 2 signals are
adequate for triggering. Typically, signals that produce even one division of vertical deflection are adequate for normal triggered sweep operation.
3. The TV H and TV V positions are primarily for
viewing composite video waveforms. Horizontal sync
pulses are selected as trigger when the trigger COU-
PLINGswitch is set to the TV H position, and vertical
sync pulses are selected as trigger when the trigger
COUPLING switch is set to the TV V position. The
TV H and TV V positions may also be used as low
frequency reject and high frequency reject coupling,
respectively. Additional procedures for observing video
waveforms are given later in this section of the manual.
13
OPERATING INSTRUCTIONS
Trigger SOURCE Switch
The trigger SOURCE switch (CH 1, CH 2, etc.) selects
the signal to be used as the sync trigger.
1. If the SOURCE switch is set to CH 1 (or CH 2) the
channel 1 (or channel 2) signal becomes the trigger
source regardless of the VERTICAL MODE selection.CH 1,orCH 2 are often used as the triggersource
for phase or timing comparison measurements.
2. By setting the SOURCE switch to ALT (same as
CH1) and PULL ALT TRIG pulled, alternating triggering mode is activated. In this mode, the trigger
source alternates between CH 1 and CH 2 with each
sweep. This is convenient for checking amplitudes,
waveshape, or waveform period measurements, and
even permits simultaneous observation of two waveforms which are not related in frequency or period.
However,this setting isnot suitable forphase or timing
comparison measurements. For such measurements,
both traces must be triggered by the same sync signal.
Alternate triggering can only be used in dual-trace
mode (VERT MODE set to DUAL), and with alternate sweep only (PULL CHOP not engaged).
3. In the LINE position, triggering is derived from the
input line voltage (50/60 Hz) and the trigger
SOURCE switch is disabled. This is useful for measurements that are related to line frequency.
4. In the EXT position, the signal applied to the EXT
TRIG jack becomes the trigger source. This signal
must have a timing relationship to the displayed waveforms for a synchronized display.
TRIG LEVEL/PULL (–) SLOPE Control
(Refer to Fig. 3)
A sweep trigger is developed when the trigger source
signalcrosses a preset threshold level.Rotation of the TRIG
LEVEL control varies the threshold level. In the + direction
(clockwise), the triggering threshold shifts to a more positive value, and in the − direction (counterclockwise), the
triggering threshold shifts to a more negative value. When
the control is centered, the threshold level is set at the
approximate average of the signal used as the triggering
source. Proper adjustment of this control usually synchronizes the display.
The TRIG LEVEL control adjusts the start of the sweep
to almost any desired point on a waveform. On sine wave
signals, the phase at which sweep begins is variable. Note
that if the TRIG LEVEL control is rotated toward its
extreme + or − setting, no sweep will be developed in the
normal trigger mode because the triggering threshold exceeds the peak amplitude of the sync signal.
When the PULL (–) SLOPE control is set to the + (“in”)
position, the sweep is developed from the trigger source
waveform as it crosses a threshold level in a positive-going
direction. When the PULL (–) SLOPE control is set to
the −(“out”) position, a sweep trigger is developed from the
trigger source waveform as it crosses the threshold level in
a negative-going direction.
MAIN TIME BASE Control
Set the Main Time Base TIME/DIV control to display
the desired number of cycles of the waveform. If there are
too many cycles displayed for good resolution, switch to a
faster sweep time. If only a line is displayed, try a slower
sweep time. When the sweep time is faster than the waveform being observed,only part of it will be displayed, which
may appear as a straight line for a square wave or pulse
waveform.
HOLDOFF Control
(Refer to Fig. 4)
A “holdoff” period occurs immediately after the completion of each sweep, and is a period during which triggering
of the next sweep is inhibited. The normal holdoff period
varies with sweep rate, but is adequate to assure complete
retrace and stabilization before the next sweep trigger is
permitted. The HOLDOFF control allows this period to be
extended by a variable amount if desired.
Slope “–” Range
Slope “+” Range
+
Level
–
Fig. 3. Function of Slope and Level Controls.
A. Holdoff not used
B. Holdoff used
Fig. 4. Use of HOLDOFF Control.
14
OPERATING INSTRUCTIONS
This control is usually set to the MIN position (fully
counterclockwise) because no additional holdoff period is
necessary. The HOLDOFF control is useful when a complex series of pulses appear periodically such as in Fig. 4B.
Improper sync may produce a double image as in Fig. 4A.
Such a display could be synchronized with the VA R
SWEEP control, but this is impractical because time measurements are then uncalibrated. An alternate method of
synchronizing the display is with the HOLDOFF control.
The sweep speed remains the same, but the triggering of the
next sweep is “held off” for the duration selected by the
HOLDOFF control. Turn the HOLDOFF control clockwise from the MIN position until the sweep starts at the
same point of the waveform each time.
MAGNIFIED SWEEP OPERATION
Since merely shortening the sweep time to magnify a
portion of an observed waveform can result in the desired
portion disappearing off the screen, magnified display
should be performed using magnified sweep.
Using the POSition control, move the desired portion
of waveformto the center of the CRT. Pull out the PULL X10
knob to magnify the display ten times. For this type of display
the sweep time is the Main Time Base TIME/DIV control
setting divided by 10. Rotation of the POSition control can
then be used to select the desired portion of the waveforms.
X−Y OPERATION
X−Y operation permits the oscilloscope to perform many
measurements not possible with conventional sweep operation. The CRT display becomes an electronic graph of two
instantaneous voltages. The display may be a direct comparison of the two voltages such as stereoscope display of
stereo signal outputs. However, theX−Y mode can be used
to graph almost any dynamic characteristic if a transducer is
used to change the characteristic (frequency, temperature,
velocity, etc.) into a voltage. One common application is frequencyresponse measurements,where the Yaxis correspondsto
signal amplitude and the X axis corresponds to frequency .
1. On the Model 2160A, set the SWEEP MODE switch
totheX−Yposition. On the Model 1541D, depress the
X−Y switch. On both models, set the Trigger Source
and VERTical MODE switches to X−Y.
2. In this mode, channel 1 becomes the X axis input and
channel 2 becomes the Y axis input. The X and Y
positionsare now adjusted usingthe POSitionand
the channel 2 POSition controls respectively.
3. Adjust the amount of vertical (Y axis) deflection with
the CH 2 VOLTS/DIV and VARIABLE controls.
4. Adjust the amount of horizontal (X axis) deflection
with the CH 1 VOLTS/DIV and VARIABLE controls.
VIDEO SIGNAL OBSERVATION
Setting the COUPLING switch to the TV-H or TV-V
position permits selection of horizontal or vertical sync
pulses for sweep triggering when viewing composite video
waveforms.
When the TV-H mode is selected, horizontal sync pulses
are selected as triggers to permit viewing of horizontal lines
of video. A sweep time of about 10 µs/div is appropriate for
displaying lines of video. The VAR SWEEP control can be
set to display the exact number of waveforms desired.
When the TV-Vmode is selected, verticalsync pulses are
selected as triggers to permit viewing of vertical fields and
frames of video. A sweep time of 2 ms/divis appropriate for
viewing fields of video and 5 ms/div for complete frames
(two interlaced fields) of video.
At most points of measurement, a composite video signal
is of the (−)polarity, that is, the sync pulses are negative and
the video is positive. In this case, use (− ) SLOPE. If the
waveform is taken at a circuit point where the video waveform is inverted, the sync pulses are positive and the video
is negative. In this case, use (+) SLOPE.
APPLICATIONS GUIDEBOOK
B+K Precision offers a “Guidebook to Oscilloscopes”
which describes numerous applications for this instrument
and important considerations about probes. It includes a
glossary of oscilloscope terminology and an understanding
of how oscilloscopes operate. It may be downloaded free of
charge from our Website, www.bkprecision.com.
DELAYED SWEEP OPERATION (Model 2160A)
(Refer to Fig. 5)
Delayed sweep operation is achieved by use of both the
main sweep and the delayed sweep and allows any portion
of a waveform to be magnified for observation. Unlike X10
magnification, delayed sweep allows selectable steps of
magnification.
1. SettheSweepMode switch to the MAIN position and
adjust the oscilloscope for a normal display.
2. Set the Sweep Mode switch to the MIX position. The
display will show the main sweep on the left portion
(representing the MAIN Time Base control setting)
and the delayed sweep on the right portion (representing the DELAY Time Base control setting). The
MAIN Time Base portion of the trace usually will be
brighter than the delayed time base portion. Fig. 5
shows a typical display for the MIX display mode.
3. Shift the percentage of the display that is occupied by
the main sweep by adjusting the DELAY TIME
POSition control. Counterclockwise rotation causes
more of the display to be occupied by the main sweep
15
OPERATING INSTRUCTIONS
Delayed Sweep
100
90
Main
10
0
Sweep
Fig. 5. MIX SWEEP MODE Display.
and clockwise rotation causes more of the display to
be occupied by the delayed sweep.
4. Set the Sweep Mode switch to the DELAY position
to display only the magnified delayed sweep portion
of the display.
NOTE
In order to obtain meaningful results with
delayed sweep, the DELAY Time Base
control must set be set to a faster sweep
speed than the MAIN Time Base control.
Because of this, the oscilloscope automatically prevents (electrically) the DELAY
Time Base from being set to a slower
sweep speed than the MAIN Time Base.
Forexample, if the MAINTimeBase is set
to0.1 ms/div, theslowest possibleDELAY
TimeBase sweep speed is also 0.1ms/div,
even if the control is set slower.
COMPONENT TEST OPERATION
(Model 2160A)
Do not apply an external voltage to the
COMP TEST jacks. Only non-powered
circuits should be tested with this unit.
Testing powered circuits could damage
the instrument and increase the risk of
electrical shock.
The component test function produces a component “signature” on the CRT by applying an ac signal across the
device and measuring the resulting ac current. The display
represents a graph of voltage (X) versus current (Y). The
component test function can be used to view the signatures
of resistors, capacitors, inductors, diodes, and other semiconductor devices. Devices may be analyzed in-circuit or
out-of-circuit and combinations of two or more devicesmay
be displayed simultaneously. Each component produces a
different signature and the components can be analyzed as
outlined below.
Component Test mode is activated by depressing the
COMPonent TEST switch. The SWEEP MODE switch
must not be in the DELAY position.
Resistors
A purely resistive impedance produces a signature that is
a straight line. A short circuit produces a vertical line and an
open circuit causes a horizontal line. Therefore, the higher
the resistance, the closer to horizontal the trace will be.
Values from 10 Ω to about 5 kΩ are within measurement
range. Values below 10 Ω will appear to be a dead short
while values above 5 kΩ will appear to be an open circuit.
Fig. 6 shows some typical resistance signatures.
To test a resistor,insertone of the resistor’sleads into the
white COMP TEST jack, and the other into the GND jack
(make sure that the leads touch the metal walls inside the
jacks). To test in-circuit, a pair of test leads can be used to
connect the COMP TEST and GND jacks to the component(s).
Capacitors
Besureto dischargecapacitors (by shorting the leads together) before connecting
to the COMP TEST jack. Some capacitors can retain a voltage high enough to
damage the instrument.
A purely capacitive impedance produces a signature that
is an ellipse or circle. Value is determined by the size and
shape of the ellipse. A very low capacitance causes the
ellipse to flatten out horizontally and become closer to a
straight horizontal line and a very high capacitance causes
the ellipse to flatten out vertically and become closer to a
straight vertical line. Values from about 0.33 µF to about
330 µF are within measurable range. Values below 0.33 µF
will be hard to distinguish from an open circuit and values
above330 µF will be hard to distinguish from ashort circuit.
Fig. 7 shows several typical capacitance signatures.
To test a capacitor,insert the capacitor’spositive lead into
the white COMP TEST jack, and the negative lead into the
GND jack (make sure that the leads touch the metal walls
inside the jacks). Totest in-circuit or to test a capacitor with
leadsthat aretoo short tofit intotheCOMPTESTand GND
jacks, a pair of test leads can be used to connect the COMP
TEST and GND jacks to the component(s).
16
OPERATING INSTRUCTIONS
100
90
10
100
90
10
0
Open Circuit
100
90
0
Short Circuit
100
90
10
10
0
10 Resistor
Ω
100
90
10
0
200 Resistor
Ω
0
5.1 k ResistorΩ
Fig. 6. Typical Resistive Signatures.
17
OPERATING INSTRUCTIONS
100
90
10
0
0.33 F Capacitorµ
100
90
Inductors
Like capacitance, a purely inductive impedance produces
asignaturethat is an ellipse or circle and valueis determined
by the size and shape of the ellipse. A very high inductance
causes the ellipse to flatten out horizontally and a very low
inductance causes the ellipse to flatten out vertically.Values
from about 0.05 H to about 5 H are within measurement
range. Values below 0.05 H will be hard to distinguish from
a short circuit and values above 5 H will be hard to distinguish from an open. Fig. 8 shows several typical inductance
signatures.
To test an inductor, insert one of the inductor’s leads into
the white COMP TEST jack, and the other into the GND
jack (make sure that the leads touch the metal walls inside
the jacks). To test in-circuit or to test an inductor with leads
that are too short to be inserted into the COMP TEST and
GND jacks, a pair of test leads can be used to connect the
COMP TEST and GND jacks to the component(s).
100
90
10
100
90
10
0
10
0
4.7 F Capacitorµ
1 Henry Inductor
100
90
0
300 F Capacitorµ
10
0
5 Henry Inductor
Fig. 7. Typical Capacitive Signatures.
Fig. 8. Typical Inductive Signatures.
18
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