Measurement Bench · Amplitude Modulation (AM) Waveform generator(8) 33220A (Agilent) The AM is a...

Dr. L.Scucchia

Measurement Bench

• Accessories

• Power supply

• Wave form generator

• Multimetre

• Oscilloscope

Dr. L.Scucchia

ACCESSORIES

Dr. L.Scucchia

Accessories (1)

Cables with BNC-croccodile connectors:

This kind of cable will be used to provide the

AC signal to the circuit to be measured.

Cables with Banana-croccodile connectors:

This kind of cables will be used to provide the

supply voltage to the circuit.

Dr. L.Scucchia

Compensate Probes

They are used to connect the oscilloscope to

the circuit to be measured.

They permit to cancel the effect of the equivalent

capacitance at the oscilloscope input.

Typically the probe is provided with a slide switch with two possible connections:

1X no compensation

10X the signal is attenuated by 10 times and there is compensation

Accessories (2)

10

1 9

20

9 1 20

Oscill . Signal

XOscill . Signal

X

X

MV f V

M M

C pFV f V

C pF pF

M C pF M pF

Dr. L.Scucchia

The breadboard or card for prototypes is a device easy to use. It allows you to

create circuit prototypes without soldering, with the advantage, then, you

can easily modify the prototypes.

Accessories (3)

Dr. L.Scucchia

Inside the device consists of several series of metal clips.

The arrangement of the clip on the breadboard produces rows of five hole

connected together (socket strip) and some collector lines (bus strip): the first

are normally used for the connection of the electronic components whereas the

latter are employed for the connections of supply or ground

Accessories (4)

The collector lines typically are

disconnected to the center.

Dr. L.Scucchia

Accessories (5)

The component connection is achieved by inserting the

connectors of the components in holes electrically

connected. The figure shows the case of two

resistors connected in series.

Particular care must be taken to connect

components with three terminals. For

example in the case of the transistor; C, B

and E must be connected to 3 different

rows of holes.

The components with dual in-line

package must be placed across

the center line of the

breadboard, in this way each leg

may be connected to a different

row of holes. E B

C

E B C

Dr. L.Scucchia

POWER SUPPLY

The power supply is a dc voltage generator, and it is the tool through which it

is possible to provide the electric power necessary for the proper operation of

the circuit to be measured.

Dr. L.Scucchia

Power supply (5)

E3630A (Agilent)

1. Power Switch

2. To view the 0 +6 V output

3. To view the 0 +20 V output

4. To view the 0 -20 V output

5. Voltage output from 0 to +6 V

6. Common terminal

7. Voltage output from 0 to +20 V

8. Voltage output from 0 to -20 V

9. Terminal for the ground connection

10.Alignment control knob

11.± 20V Control knob output

12.6VControl knob output

13.Overload LED

14.Current display

15.Voltage display

1

2 3 4

9 8 7 6 5

12 11 10 14 13

15

Dr. L.Scucchia

• This power supply provides:

2 outputs in tracking mode with a maximum voltage ±20V (0.5A),

1 output with a maximum voltage +6 V (2.5A).

• The outputs in tracking mode can be used in series to provide a voltage of 40V

(0.5A).

• if a load change causes the current limit to be exceeded, the OVERLOAD

LED is lighted.

• The three outputs share the COM terminal, isolated from the grounding of the

chassis.

• The reference mass is achieved by connecting the terminal COM to the

terminal ┴

Alimentatori (6)

E3630A (Agilent)

Dr. L.Scucchia

V

Vmax V’

I

Voltage control

Overload

Imax

Dr. L.Scucchia

WAVEFORM GENERATOR

Dr. L.Scucchia

Waveform generator (1)

It generates a periodic waveform that can be injected at the input of the circuit

to be measured.

Connecting the oscilloscope probes at the input and output of the circuit one can

evaluate the behavior of the circuit with respect to the injected waveform.

The output terminal of the function generators commonly consists of a BNC

connector with an impedance of 50

Typical signals which can be obtained are:

Sinusoidal waveforms.

Triangular waveforms.

Rectangular waveforms.

Dr. L.Scucchia

Waveform generator(2)

33220A (Agilent)

9 Manual Trigger Key

10 Output Enable/Disable Key

11 Knob

12 Cursor keys

13 Sync Connector

14 Output Connector

15 Numeric pad

16 Display

1 On/Off Switch

2 Graph Mode Key

3 Modulation/Sweep/Burst Keys

4 State Storage Menu Key

5 Utility Menu Key

6 Help Menu Key

7 Menu Operation Softkeys

8 Waveform Selection Keys

2

10 1 4

16 11

12

5 6

8

7

9 13 14 3

15

Dr. L.Scucchia

1. Press and hold any function key or softkey to display a help topic for that key or

feature. Or press Help to display the Help Menu.

2. Lighted keys indicate active keys or functions such as the currently active

waveform .

3. No signal is output unless the output key is lighted.

4. To select dc volts from the front panel, press Utility and select the DC On softkey.

5. The key Graph toggles between Graph Mode (lighted) and Menu Mode.

6. In Menu Mode, the softkeys allow you to select parameters and functions as

shown in the softkey menu at the bottom of the display. Some softkeys toggle

between related parameters. For example, the left softkey toggles between Freq

and Period below:

Referent points


33220A (Agilent)

Dr. L.Scucchia

Quick Start


33220A (Agilent)

1. Press the On/Off Switch. After a few seconds,

the instrument assumes the default values.

2. Select a waveform.

3. Change Waveform Parameters.

Use the six softkeys to select parameters.

Some softkeys toggle between related

parameters (for example: Freq and Period).

4. Parameter value can be changed using

the knob. First, use the cursor keys ( )

to select the first digit. Then use the knob to

change the first digit value

Dr. L.Scucchia


33220A (Agilent)

6 Now, press Offset to select that

parameter. Use the cursor keys to select

digits. Use the knob to set the required

offset value.

7. Now let‟s use the numeric keypad to set

the Period. Press the left softkey once to

select Freq.

8. Then press it again to select Period.

9. Key a value on the keypad. The display

changes. For example, enter 1.5.

10.Press the softkey for the desired unit (for

example, msec) to enter the value.

Dr. L.Scucchia


33220A (Agilent)

If RLoad = 50 , VLoad= 1.000Vpp

VOutput=2.000 Vpp

ROutput=50

RLoad +

VLoad

-

The 33220A has a fixed output impedance (ROutput) of 50 at the output connector.

If the load impedance (RLoad) is different from 50, the displayed amplitude and offset

levels will be incorrect.

For example, selecting a voltage 1.00 0Vpp, Voutput is equal to 2.000 Vpp

If Rload is different from 50

RLoad = 100 VLoad= 1.333Vpp

RLoad = VLoad= 2.000Vpp

Dr. L.Scucchia

If you do not know the load value,

you must estimate the voltage levels by using

the oscilloscope.

Dr. L.Scucchia


33220A (Agilent)

To Change the Output Termination

1 Press.

2 Navigate the menu to set the output termination. Press the Output Setup

softkey and then select the Load softkey.

3 Select the desired output termination.

Dr. L.Scucchia

Amplitude Modulation (AM)


33220A (Agilent)

The AM is a technique used in communication in order to transmit the

information via a carrier waveform (535 kilohertz to 1.7 megahertz).

The information is contained in the modulating waveform.

In AM, the amplitude of the carrier is varied by the modulating waveform.

carrier waveform

modulating waveform

Dr. L.Scucchia

1 Select the function, frequency, and amplitude of the carrier.

40.0

50.00

5 Select the modulating waveform shape: Press the Shape softkey to select the

shape of the modulating waveform. For this example, select a sine wave.

2 Select AM: Press and then select “AM” using the

Type softkey.


33220A (Agilent)

3 Set the modulation depth: Press the AM Depth

softkey and then set the value to 40% using the

numeric keypad or the knob and cursor keys.

4 Set the modulating frequency. Press the AM

Freq softkey and then set the value to 50 Hz using

the numeric keypad or the knob and cursor keys

Modulated Waveform at Output

Dr. L.Scucchia

MULTIMETRE

Dr. L.Scucchia

Multimetre (1)

The Multimeter is a measuring instrument that basically allows to measure currents,

voltages and resistances. There are two types of multimetres:

analog (MA) and

digital (MD).

The first employs a mechanical tracking system that shows the desired size on a

suitable scale, the latter uses a digital system to convert electrical quantities at

the input in a reading on the display.

Technically speaking the MA are less accurate than the digital ones (they are subject

to an error typically higher than 3%), are harder to read. Despite these limitations,

MA are better for measurements on circuits that have high electrical noise.

In the following, digital

multimetre will be considered, in

particular the 34401A (Agilent).

Dr. L.Scucchia

Multimetre (2)

34401A (Agilent)

1 2

3 4 5 6 7 8

1 Measurement Function keys

2 Math Operation keys

3 Single Trigger/Autotrigger/

Reading Hold key

4 Shift / Local key

5 Front / Rear Input Terminal Switch

6 Range / Number of Digits

Displayed keys

7 Menu Operation keys

8 Power switch

Turn on the multimeter.

Switching the instrument on, by pressing the 8 key, the display lights and the

meter performs a self test. To control the appearance of the display, hold down

the Shift key (4). To complete the self-test and hold for 5 seconds the Shift key.

Pressing the Shift key you can select the alternate function (in blue above the

key).

Dr. L.Scucchia

Multimetre(2)

34401A (Agilent) To Measure Voltage

Ranges: 100 mV, 1 V, 10 V, 100 V,

1000 V (750 Vac)

Maximum resolution: 100 nV (on 100

mV range)

AC technique: true RMS, ac-coupled

The 34401A provides “true RMS” (Root Mean Square) measurements. They are achieved

by the dissipated power in a resistor.

This power is proportional to the square of the true RMS voltage (VRMS), and it is

independent of waveshape.

A common way to describe signal waveshapes is crest factor. Crest factor is the ratio of the

peak value to RMS value of a waveform.

2

0

1 T

RMSV V t dtT

2

RMSdis

VP

R

ˆˆ. . ;

RMS

VC F V peak value

V

Dr. L.Scucchia

To Measure Resistance

Ranges: 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1

MΩ, 10 MΩ, 100 MΩ

Maximum resolution: 100 μΩ (on 100

ohm range)

The Agilent 34401A offers two methods for measuring resistance: 2-wire and 4-wire.

For both methods, the test current flows from the input HI terminal ad then through the resistor

being measured.

For 2-wire, the voltage drop across the resistor to be

measured is sensed internal to the multimeter.

Therefore, cable resistances are also measured.

For 4-wire, separate cable connections are required.

Since no current flows in the measurement cables, these

does not give a measurement error. This type of

measurement is more accurate since it allows to eliminate

the resistance introduced by the connecting cables

Multimetre(3)

34401A (Agilent)

Dr. L.Scucchia

To Measure Current

Ranges: 10 mA (dc only), 100 mA (dc

only), 1 A , 3 A

Maximum resolution: 10 nA (on 10 mA

range)

AC technique: true RMS, ac-coupled

Multimetre(4)

34401A (Agilent)

To Measure Frequency (or Period)

Measurement band: 3 Hz to 300 kHz

(0.33 sec to 3.3 μsec)

Input signal range: 100 mVac to 750

Vac

Dr. L.Scucchia

To Test Continuity

Test current source: 1 mA

Maximum resolution: 0.1 Ω (range is fixed

at 1 kohm)

Beeper threshold: 1 Ω to 1000 Ω (beeps

below adjustable threshold)

To Check Diodes

Test current source: 1 mA

Maximum resolution: 100 μV (range is

fixed at 1 Vdc)

Beeper threshold: 0.3 volts ≤ Vmeasured ≤

0.8 volts (not adjustable)

Multimetre(5)

34401A (Agilent)

Dr. L.Scucchia

Math Operations

There are five math operations available, only one of which can be enabled at a

time. Each math operation performs a mathematical operation on each reading or

stores data on a series of readings.

The table shows the math/measurement function combinations allowed.

Null: value subtracted from the measurement.

Min/Max: displays minimum and maximum values for the triggered set

of readings.

dB: measurement relative to value in „dB Relative‟ register

dBm: measurement relative to a resistance referenced to 1 mW

Multimetre (6)

34401A (Agilent)

The math operation Limit can be enabled using the LIMIT TEST command in the

MATH MENU.

Dr. L.Scucchia

To Select a Range

The measurement range depends on the selected function:

Voltage 100 mV, 1 V, 10 V, 100 V, 1000 V

Current 10 mA (dc only), 100 mA (dc only), 1 A , 3 A

Frequency 3 Hz to 300 kHz

Resistance 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ, 100 MΩ

You can let the multimeter automatically select the range using autoranging or

you can select a fixed range using manual ranging.

Multimetre (6)

34401A (Agilent)

Dr. L.Scucchia

To Set the Resolution

Resolution is the number of digits the multimeter can measure or display.

You can set the display resolution to 4 ½, 5 ½, or 6 ½ digits either to optimize

measurement speed or noise rejection.

The most significant digit (leftmost on the display) is the “1⁄2” digit, since it can only

be a “0” or “1.”

Multimetre(6)

34401A (Agilent)

Press the shift key Selects 4 ½ digits

Selects 5 ½ digits

Selects 6 ½ digits

To Set the Trigger

Measurements are triggered from the front panel using the keys:

Single Trig: disables auto-triggering (default) and issues a single trigger to the

34401A each time the key is pressed.

Auto: enables auto-triggering if the 34401A is in single trigger mode.

Hold: displays the measurement after three consecutive readings.

Dr. L.Scucchia

Front panel menu

It provides access to a subset of the 34401A functionality. The menu is organized in

a top-down tree structure with three levels (menus, commands, and parameters).

Multimetre (6)

34401A (Agilent)

You move down ∨ or up ∧ the menu tree to get

from one level to the next. Each of the three

levels has several horizontal choices which you

can view by moving left < or right > .

Dr. L.Scucchia

Multimetre(6)

34401A (Agilent)

Dr. L.Scucchia

OSCILLOSCOPE

Dr. L.Scucchia

Oscilloscope (1)

The oscilloscope allows to display a voltage (vertical axis - Y axis) versus

time (horizontal axis - X axis).

The oscilloscope can also display two voltages on both the axes (XY mode).

The quantities shown on the screen are voltages.

To facilitate reading of the magnitudes, on the screen there is a grid

consisting of some horizontal and vertical divisions.

The oscilloscopes in the laboratory are DSO3202A by Agilent. Digital

Storage Oscilloscope (DSO)

A digital oscilloscope uses an analog-to-digital converter (ADC) to convert

the measured voltage into digital information.

The digitized data are stored in a “channel memory”

Dr. L.Scucchia

Oscilloscope (2)

Trigger

Coupling

Attenuator Amplifier ADC Channel

Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC

DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

Yellow = Channel specific blocks

Blue = System blocks

Dr. L.Scucchia

Oscilloscope (3) A probe feeds the input signal into the oscilloscope where the

attenuator and the amplifier are used to compensate for input

levels for various voltage per division settings. The trace position

is adjusted changing the DC Offset.

Trigger

Coupling


Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC



DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

Dr. L.Scucchia

Oscilloscope (4)

The ADC provides a discrete form of the signal:

• in the time domain (sampling) and

• in the amplitude domain (quantization).

The ADC converter operates continuously at the maximum sampling frequency.

Trigger

Coupling


Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC



DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

Dr. L.Scucchia

Oscilloscope (5)

Trigger

Coupling


Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC



DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

The memory is organized as a circular buffer.

The write pointer advances at the rate of the ADC. write

pointer

Dr. L.Scucchia

Oscilloscope (6)

Trigger

Coupling


Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC



DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

The trigger signal, through the timebase system,

causes the start of the reading cycle of the channel

memory

write

pointer read

pointer

Dr. L.Scucchia

Trigger level

0 k n-1

read

pointer

Oscilloscope (7)

The trigger event defines a reading interval.

The trigger determines when captured data are stored and displayed.

On the display the result is a

signal portion preceding and

following the trigger event

Dr. L.Scucchia

Oscilloscope (8)

Trigger level

0 k n-1

0 k n-1

0 k n-1

read

pointers

Trigger problems (different trigger events)

Two or more trace on the display.

A trace in movement on the display

Dr. L.Scucchia

Oscilloscope (10)

Trigger

Coupling


Memory

Display

DSP

Trigger

Logic

Timebase

System

CPU

System

Input

BNC



DSO Block Diagram

Trigger

Comp

DC

Trigger

Level

+

-

+

DC

Offset

-

Trigger

signal

Newer DSOs use custom DSPs to quickly process data

and then send waveform data into display memory.

Dr. L.Scucchia

Oscilloscope (11)

DSO3202A (Agilent)

Power switch

Measure controls

Vertical controls

Horizontal Controls

MENU’ ON/OFF

Run controls

Menù controls

Trigger controls

Menu defined buttons

Inputs Compensation

terminals

Display

Entry knob

Waveform controls

Dr. L.Scucchia

Low Frequency Compensation

1. Set the Probe menu attenuation to 10X.

2. Attach the probe tip to the probe compensation

connector.

3. Press the Autoscale front panel button.

4. If the waveform is not rectangular you must

compensate.

5. Through a nonmetallic tool adjust the screw

located near the probe up to get a signal perfectly

compensated.

High Frequency Compensation

1. Using the BNC adapter, connect the probe to a

square wave generator.

2. Set the square wave generator to a frequency of 1

MHz and an amplitudeof 1 Vp-p.

3. Press the Autoscale front panel button.

4. If the waveform does not appear like the Correctly

Compensated waveform shown in figure, then

adjust the 2 high frequency compensation

adjustments on the probe for the flattest square

wave possible.

Oscilloscope (12)

DSO3202A (Agilent)

Dr. L.Scucchia

Oscilloscope (13)

DSO3202A (Agilent)

Display

Dr. L.Scucchia

Oscilloscope (14)

DSO3202A (Agilent)

Vertical controls

Each channel has a vertical control menu activated

by pressing the 1 or 2 keys on the front panel. The

characteristics of the track are modified using the

knobs Scale and Location.

The menu is activated by pressing MENU„ ON/OFF.

• Channel Coupling Control

• Bandwidth Limit Control

• Probe Attenuation Control

• Invert Control

• Digital Filter Controls

Mathematical operations are activated by pressing

Math.

The waveforms may be stored using the menu Ref

Dr. L.Scucchia

Connection control - pushing the button to the right of Coupling you can choose

between three possible connections:

AC for a connection via capacitor

(display the AC component)

DC for a direct connection

(display full signal)

GND for the check of the reference level

(ground voltage)

Bandwidth Limit Control - allows to

remove, from the waveform examined,

the high frequency components not

relevant to the measurement made. Press

the key corresponding to BW Limit

function is activated (ON) and all

components at frequencies greater than

20 MHz are rejected.

Oscilloscope (15)

DSO3202A (Agilent)

Dr. L.Scucchia

Control probe attenuation - Allows you to specify the

attenuation on the probe selected. The probe attenuation

control changes the attenuation factor for the probe.

The attenuation factor changes the vertical scaling of the

oscilloscope so that the measurement results reflect the

actual voltage levels at the probe tip.

Invert control - The invert control inverts the displayed waveform with respect to the

ground level.

Digital filter controls - Pressing the Digital Filter menu key displays the Filter Controls.

The filter controls set the digital filter

used to filter the sampled waveform

data. The types of filters that are

available are shown in the table.

Oscilloscope (16)

DSO3202A (Agilent)

Dr. L.Scucchia

Oscilloscope (17)

DSO3202A (Agilent)

Horizontal controls

The oscilloscope shows the time per division

in the status bar, only one value for all

waveforms.

The controls Scale and Position allow to

change scale and position of the waveform.

The menu associated with the time base is

activated by pressing the Main/Delayed.

Delayed ON/OFF

Time Base Y-T/X-Y

Trig–Offset Reposition the track

Holdoff Change the instant trigger

Holdoff Reset

Dr. L.Scucchia

With Delayed command you can enable or

disable delayed sweep mode. In this mode,

the screen is divided into two parts, the upper

part shows the original waveform while the

lower part shows an enlarged view. The

enlarged portion is called the delayed sweep

window. and the monopole of scale and

horizontal position control the relevant

parameters of the waveform.

The key for Time Base allows you to choose the

format TY and XY. In XY format, the vertical

displacement of the trace on the screen depends

on the signal on channel 1 while the horizontal

deviation depends on the signal on channel 2. In

XY format many as the functions are not

supported.

Oscilloscope (18)

DSO3202A (Agilent)

Dr. L.Scucchia

The holdoff time is the period of waiting

before starting a new trigger to change the

duration of this interval is sufficient to press the

key next to Holdoff and adjust the time using

the knob added. Pressing the Reset holdoff the

holdoff time is set to its minimum value of

100ns.

The Trig-Offset button allows you to relocate the center of the track displayed

on the screen.

Oscilloscope (19)

DSO3202A (Agilent)

Dr. L.Scucchia

Oscilloscope (20)

DSO3202A (Agilent)

Trigger controls

Level: it changes the voltage level of the trigger signal.

Force: it forces the acquisition.

50%: voltage level of the trigger signal is set equal to

the average value.

Ext Trig: external trigger.

Mode/Coupling: Trigger menu is activated.

• Mode Edge, Pulse e Video (metods)

• Source CH1, CH2, ext, …

• Slope

• Sweep Auto, Normal

• Coupling AC, DC, LFrejet e HFrejet

Dr. L.Scucchia

Oscilloscopio (21)

3202A (Agilent)

Waveform

Acquire

Controlls

Display

Controls

Type: Vectors, Dots

Grid:

Persist: Infinite, OFF

Clear:

Menù Display: 1s,2s,5s…

Screen: Normal,Invert

Mode: Normal, Average, Peak_detect

Sampling methods:Real time, Equ time

Averages: 2-256

Sequence:

The Average mode allows to remove random noise from the waveforms thus

improving the accuracy of the measurement. To avoid aliasing is useful acquiring

type Peak Detect. Real time is recommended to observe non-periodic signals,

whereas Equ-time allows to visualize high frequency signals better. The

command Sequence allows to record the waveform input from the channel 1 or 2,

with a depth of acquisition of 1000 frames.

Pressing the Display button the corresponding menu is shown where you can

specify the display characteristics of the track and the grid.

Dr. L.Scucchia

Real-time sampling

In the real-time sampling mode, single waveforms are

sampled at same intervals.

The digitizer works at maximum speed to acquire as

many points as possible in one sweep, and the 3000

Series oscilloscopes provide sampling rates up to 1

GSa/s.

In real-time sampling the trigger event happens on a

particular feature of the waveform (amplitude). In this

type of data acquisition, the sample rate of the ADC

determines the sample spacing and the number of points

that will be displayed.

Oscilloscopio (22)

DSO3202A (Agilent)

Equivalent time Sampling

The input signal is only sampled once per

trigger.

At the next triggered, a small delay is added

and another sample is taken.

The number of samples determines the

necessary number of cycles to reproduce the

waveform.

Dr. L.Scucchia

Sourcee: CH1, CH2

Voltage: Vpp,Vmax, Vmin, Vavg,...

Time Freq, Period,

Clear

Display All: OFF, ON Measure

Controls Manual: Menù

Track: Menù

Auto Measure: Menù

Cursor

Meas

Oscilloscope (23)

DSO3202A (Agilent)

Meas button on the front panel activates the automatic measurement system, in

particular this enables oscilloscope to perform 20 different measures including:

Vpp, Vmax, Vmin, Vamp, Vavg, Vrms, Freq, Period, risetime and Fall Time.

The Cursor button on the front panel activates the menu corresponding to the

measures concerning the marker. There are three modes: Manual, Track and Auto

Measure.

• Manual, the screen shows two parallel cursors that can be moved on the track in

order to obtain the measures of voltage or of time desired. The

values corresponding to the cursors are shown in the upper part of the screen.

• Track, two sliders are automatically activated that can be adjusted using the

added knob.

• Auto Measure, available when the measurement system is automatically

activated, the oscilloscope displays the cursor in relation to the latest measures

used.

Dr. L.Scucchia

Voltage measurements:

• Vpp (Peak-to-Peak Voltage)

• Vmax (Maximum Voltage)

• Vmin (Minimum Voltage)

• Vavg (Average Voltage)

• Vamp (Amplitude Voltage = Vtop - Vbase)

• Vtop (Top Voltage)

• Vbase (Base Voltage)

• Vrms (True Root-Mean-Square Voltage)

• Overshoot (Measure the overshoot voltage in percent (Vmax-Vtop)/Vamp. Overshoot is a waveform

distortion which follows a major edge transition)

• Preshoot (Measure the preshoot voltage in percent (Vmin-Vbase)/Vamp,. Preshoot is a waveform

distortion which precedes a major edge transition)

Oscilloscope (24)

DSO3202A (Agilent)

Dr. L.Scucchia

Time Measurements:

• Frequency

• Period

• Rise Time

• Fall Time

• +Width

• -Width

• +Duty

• -Duty

• Delay 1→2

• Delay 1→2

Oscilloscopio (25)

3202A (Agilent)

Dr. L.Scucchia

t1 t2

Channel 2

50%

50%

Channel 1

Oscilloscope (26)

DSO3202A (Agilent)

Delay 1-2, rising edges

Channel 2

50%

50%

Channel 1

Delay 1-2, falling edges

Delay From channel 1 to channel 2

rising edges ( = t2-t1)

Delay From channel 1 to channel 2

Falling edges ( = t2-t1)

t1 t2

Dr. L.Scucchia

Oscilloscope(27)

DSO3202A (Agilent)

Utility

Controlls

Mask Test: Menù

I/OSetup Menù

Language: English,…..

Sound: ,

System Info

Self-Cal

Self-Test

Save and

Recall

Controlls

Save/Recall: Waveforms,

Setups

Default Setup

Waveform: 1-10

Setup: 1-10

Load

Save

Controls Autoscale and Run/Stop

The Autoscale key is used to retrieve and set automatically the oscilloscope controls

necessary for a good display of the waveform at the input.

The Run/Stop key on the front panel of the oscilloscope starts or stops the acquisition

system of the oscilloscope. When the acquisition is stopped, the button is red and the

vertical and horizontal scales can be changed within a fixed interval

Dr. L.Scucchia

V p

-p

Period

Horizontal = 1 µs/div

V m

ax

Ground level (0.0 V)

indicator

Vertical = 1 V/div

Period (T) = 4 divisions x 1 µs/div = 4 µs, Freq = 1/T = 250 kHz.

Vp-p = 6 divisions x 1 V/div = 6 V p-p

Vmax = +4 divisions x 1 V/div = +4 V

Vmin = Vmax-Vp-p = -2 V

Making Measurements by visual estimation

Oscilloscope(28)

DSO3202A (Agilent)

Dr. L.Scucchia

Oscilloscope (29)

DSO3202A (Agilent)

The math functions control allows the selection of the math functions add,

subtract, multiply, and FFT (Fast Fourier Transform) for CH1 and CH2. The

mathematical result can be measured visually and also using the cursor controls.

The FFT of a waveform that has a DC component or offset can cause incorrect FFT

waveform magnitude values. To minimize the DC component, choose AC Coupling on the

source waveform.

To reduce random noise and aliasing components in repetitive or single-shot waveforms, set

the oscilloscope acquisition mode to averaging.

To display FFT waveforms with a large dynamic range, use the dBVrms scale. The dBVrms

scale displays component magnitudes using a log scale.

The FFT math function mathematically converts a

time-domain waveform into its frequency

components.

Dr. L.Scucchia

Selecting an FFT Window

FFT based measurements are subject to errors from an effect known as leakage.

This effect occurs when the FFT is computed from of a block of data which is not

periodic. To correct this problem appropriate windowing functions must be applied.

The window is shaped so that it is exactly zero at the beginning and end of the data

block and has some special shape in between.

For the 3202A there are 4 FFT windows. Each window has trade-offs between

frequency resolution and amplitude accuracy. Your source waveform characteristics

along with your measurement priorities help determine which window to use.

Oscilloscope (30)

DSO3202A (Agilent)

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