PASCO WA-9611_13 SONOMETER - Manual (Page 5)

1
012-03489E Sonometer
Introduction
Figure 1 The Sonometer and Suggested Accessories
DETECTOR
WA-9613
DRIVER
WA-9613
WA-9611
SONOMETER
KEEP WEIGHTS AS NEAR TO FLOOR AS POSSIBLE IN THE EVENT THE SONOMETER WIRE SHOULD BREAK
CAUTION! 1.75 kg MAXIMUM LOAD ON LEVER
Bridge String
Tensioning
lever
Sonometer base
Introduction
The PASCO scientific Model WA-9611 Sonometer is an
enhanced version of the classic sonometer. You can per-
form the standard, qualitative sonometer experiments,
varying the tension, length, and linear density of the string
and observing the effects on the pitch of the plucked string.
Also, you can perform quantitative experiments, verifying
the equations for wave motion on a string by adding the
WA-9613 Driver/Detector Coils, a function generator ca-
pable of delivering 0.5 A of current, and an oscilloscope (or
a computer interface and power amplifier) where,
l = wavelength
L = length of string
n = number of antinodes
V = velocity of wave propagation
T = string tension
m = linear density of string
n = frequency of wave
The driver and detector coil can be placed anywhere along
the string. The driver coil drives string vibrations at any
frequency your function generator (or computer-compat-
ible power amplifier) will produce. The detector coil allows
you to view the vibration of the string on your oscilloscope
or computer interface. With a dual trace oscilloscope or a
computer interface, you can examine phase differences be-
tween the driving frequency and the string vibrations.
Equipment
The WA-9611 Sonometer comes with the following
equipment (see Figure 1):
• Sonometer base with tensioning lever
• Two bridges
• 10 wires (guitar strings), 2 each of the following di-
ameters (linear densities):
— 0.010" (0.39 gm/m)
— 0.014" (0.78 gm/m)
— 0.017" (1.12 gm/m)
— 0.020" (1.50 gm/m)
— 0.022" (1.84 gm/m)
Additional Equipment
To perform qualitative experiments, you will also need a
mass hanger and no more than 1.75 kg of mass to hang
from the tensioning lever.
Recommended Equipment
If you wish to accurately measure the frequency and
wavelength of the string vibrations, you will also need:
• WA-9613 Driver/Detector coils
• CI-6550 or CI-6565 Computer Interface and a
Power Amplifier (CI-6552)
OR
•
Series 6500 Computer Interface, CI-6508 Input
Adapter Box, and a function generator capable of
producing 0.5 A
OR
•
dual trace oscilloscope and a function generator
capable of producing 0.5 A
Optional Equipment (for use with function
generator)
• banana plug patch cords and BNC-to-banana
adapter (for connecting the function generator to
the BNC connector on an oscilloscope)