PASCO CI-6506B User Manual

Instruction Sheet
for the PASCO
Model CI-6506B

012-06296B

SOUND SENSOR

DIN connector

Sound Sensor

CI-6506B

SOUND

SENSOR

aperture for sensor

Introduction

The PASCO CI-6506B Sound Sensor is designed to be
used with a PASCO computer interface to make
measurements of relative intensity of sound.

The sensing element of the Sound Sensor is an electret
condenser microphone, which consists of an electret
membrane, metal electrode, and field effect transistor that
are in an efficient configuration yielding superior signal­to-noise ratios (>60 dB) and excellent frequency response
(20 to 16,000 Hz).

Two stages of amplification are provided to condition the
low-level signal from the microphone for input into the
Science Workshop computer interface. The output from
the sensor is bipolar and ranges between ±10 volts. When
the sensitivity is raised to high in Science Workshop (700
interface only), the Sound Sensor detects voltage levels as
low as 0.0005 volts, corresponding to sound levels that
are barely audible to the human ear. Sound levels ranging
from classroom background noise (45 dB) to levels
exceeding 100 dB are easily detected with the Sound
Sensor.

interface cable with

DIN connectors

to computer interface

with the Sound Sensor: the Oscilloscope allows the
student to view the Sound Sensor output directly, and the
FFT function will transform the time domain signal from
the sensor to a frequency domain display. These two
functions allow the student to investigate the frequency
composition of sound produced by the human voice, a
tuning fork, or loud speaker driven by a complex
waveform such as a square wave. Both the Oscilloscope
and FFT functions may be used simultaneously.

The Sound Sensor can be plugged directly into any
PASCO computer interface box or can be connected to the
interface box using the supplied cable with 8-pin DIN
connectors.

Equipment Included:

• sound sensor in sensor box

• 6-foot cable with 8-pin DIN connectors

Additional Equipment Required:



• Any PASCO Science Workshop
(300, 500, or 700 series for Macintosh or Windows)
or the 6500 series interface for DOS

computer interface

The Oscilloscope and Fast Fourier Transform (FFT)
functions of Science Workshop may be used effectively

© 1997 PASCO scientific
Author: Sunny Bishop

Sound Sensor

Additional Equipment Suggested:

• Tuning Forks (SE-9325 or SE-9326)

• Organ Pipe with Sliding Piston (SF-9328)

• Acoustics Demonstration Disk (SF-9410)

Setup Procedure

➀ Connect the Sound Sensor and any analog channel on

the computer interface box with interface cable
(Figure 1A),

or

insert the DIN plug of the Sound Sensor into the jack
of any analog channel on the computer interface box
(Figure 1B).

The sound level, which is measured in decibels can
be calculated from amplitude of the voltage. The for­mula is.

B = 10 * log(A^2/A(0)^2)

Where A is the amplitude of the voltage and A(0) is
the theoretical amplitude for a sound level of 0 dB.

At a frequency of 440 Hz, A(0) = 10 ^ -4 volts ap­proximately.

To have Data Studio perform this calculation, click on
th Calculate button and type the following equation:

sound level = 10*log(amplitude (10,10,.001, v^2)/(10^-

8).

In the Variables section of the Calculator, define v as
Voltage, Ch A.

This equation is optimized for a sine wave at 440 Hz,
so you may need to adjust the third argument of the
amplitude function (it should be about equal to the pe­riod of the wave).

The value of 10^-4 volts is also optimized for 440 Hz.
Since the response of the sound sensor varies with
frequency, you may want to calibrate the equation for
a different frequency. To do so, you would need a
stand-alone sound level meter. Measure the sound
level of as sound (B) with the meter, and the voltage
amplitude (A) with the sound sensor. Use these val­ues to solve for A(0) in the first equation above.

ANALOG CHANNELS

™

ScienceWorkshop

®

s

n

A

C

A

500

Interface

E

S

R

S

1

P

T

G

O

O

L

DIGITAL CHANNELS

B

2

ON

=

=

GAIN

GAIN

=

GAIN

1,10:ISOLATED

1,10: REF TO GND

1: REF TO GND

012-06296B

Figure 1. Connecting the Sound Sensor into the computer
interface.

➁ Open the Experiment Setup window in

Science Workshop. Click and drag the analog plug icon
to the analog channel icon that matches the analog port
you are using for the Sound Sensor (Figure 2).

Figure 2. Activating the analog channel in

Science Workshop.

➂ Select "Sound Sensor" from the drop-down menu

(Figure 3).

Figure 3. Setting up the Sound Sensor in Science Workshop.

Plug into

any analog

channel.

R

O

S

D

N

N

E

U

O

S

B

6

0

5

6

-

I

C

ANALOG CHANNELS

™

ScienceWorkshop

®

s

n

A

C

B

500

Interface

E

S

R

S

1

P

T

G

O

O

L

DIGITAL CHANNELS

B

2

ON

=

=

GAIN

GAIN

=

GAIN

1,10:ISOLATED

1,10: REF TO GND

1: REF TO GND

➃ Open a display window, such as the Oscilloscope

display, by dragging and dropping the appropriate
display icon to the Sound Sensor icon (Figure 4).

B

6

0

5

6

-

I

C

D

N

U

R

O

O

S

S

Plug into any

N

E

S

S

analog

channel.

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012-06296B

1

4

3

5

2

6

7

8

Figure 4. Opening a Display window in Science Workshop.

➄ Additional display windows can be opened by

following the procedure in step 4.

Calibration and Sensitivity Adjustment in

Science W orkshop

Sound Sensor

Mounting on an Experimental Apparatus

Use the 1/4-20 screw connector located on the

➀

bottom of the sensor box to secure the Sound Sensor to
an experimental apparatus (Figure 6). The alignment
hole fits over an alignment pin included on some
PASCO apparatuses.

alignment hole

1/4-20 screw

connector

Figure 6. Mounting connector and alignment hole.

➀ To open the Sound Sensor's calibration window,

double-click on the Sound Sensor icon in the
Experiment Setup window (see Figure 4).

➁ The sensitivity (gain) of channels A and B of the 300,

500, and 700 interfaces in Science Workshop can be

adjusted by selecting the appropriate level from the
drop-down menu (Figure 5). If the Sound Sensor is
producing voltage above 1 V, the sensitivity should be
set to Low (1x). If the Sound Sensor is producing
voltages between +1 V and -1 V, select Medium (10x).
With the Science Workshop 700 interface, the
sensitivity can be set to High (100x) if the voltage is
very low (between +0.1 V and -0.1 V). Refer to the
User's Guide for Science Workshop for more details
concerning calibration and adjusting the sensitivity
setting.

DIN Connector Specifications

1: analog output (+),

0 to 10 V

2: analog output (-),

signal ground

3: (no connection)
4: + 5 V DC power
5: power ground
6: +12 VDC power
7: -12 VDC power
8: (no connection)

Figure 5. Dialog box for calibrating and adjusting the gain
for the Sound Sensor in ScienceWorkshop.

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Sound Sensor

012-06296B

Copyright, W arranty, and Equipment Return

Please—Feel free to duplicate this manual
subject to the copyright restrictions below.

Copyright Notice

The PASCO scientific 012-06296A instruction sheet is
copyrighted and all rights reserved. However, permission
is granted to non-profit educational institutions for
reproduction of any part of the Sound Sensor instruction
sheet providing the reproductions are used only for their
laboratories and are not sold for profit. Reproduction
under any other circumstances, without the written consent
of PASCO scientific, is prohibited.

Limited Warranty

PASCO scientific warrants the product to be free from
defects in materials and workmanship for a period of one
year from the date of shipment to the customer. PASCO
will repair or replace, at its option, any part of the product
which is deemed to be defective in material or workman­ship. The warranty does not cover damage to the product
caused by abuse or improper use. Determination of
whether a product failure is the result of a manufacturing
defect or improper use by the customer shall be made
solely by PASCO scientific. Responsibility for the return
of equipment for warranty repair belongs to the customer.
Equipment must be properly packed to prevent damage
and shipped postage or freight prepaid. (Damage caused
by improper packing of the equipment for return shipment
will not be covered by the warranty.) Shipping costs for
returning the equipment after repair will be paid by
PASCO scientific.

Equipment Return

Should the product have to be returned to PASCO
scientific for any reason, notify PASCO scientific by
letter, phone, or fax BEFORE returning the product. Upon
notification, the return authorization and shipping instruc­tions will be promptly issued.

➤➤

➤

NOTE: NO EQUIPMENT WILL BE

➤➤

ACCEPTED FOR RETURN WITHOUT AN
AUTHORIZATION FROM PASCO.

When returning equipment for repair, the units must be
packed properly. Carriers will not accept responsibility for
damage caused by improper packing. To be certain the
unit will not be damaged in shipment, observe the
following rules:

➀ The packing carton must be strong enough for the item

shipped.

➁ Make certain there are at least two inches of packing

material between any point on the apparatus and the
inside walls of the carton.

➂ Make certain that the packing material can not shift in

the box, or become compressed, allowing the
instrument come in contact with the edge of the
packing carton.

Address: PASCO scientific

10101 Foothills Blvd.

P.O. Box 619011

Roseville, CA 95678-9011

Phone: [phone]

FAX: [phone]

email: [e-mail]

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