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.
2
®
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