How to Measure the Frequencies of Tuning Forks

A tuning fork is an acoustic resonator that resembles a fork consisting of two prongs, or tines. When struck by another object, the fork's tines vibrate and produce sound waves as a result. When British musician John Shore invented the tuning fork in 1711, he may not have realized that his creation would go on to become an educational tool, as physics instructors often ask students to determine the frequency of a tuning fork.

Things You'll Need

• Sound sensor
• Data logger

Instructions

1. Connect the sound sensor to the data logger.

2. Alter the sound sensor's settings according to the manufacturer's instructions so that the device measures the sound waves in millivolts (mV).

3. Launch the graphing application on the sound sensor as instructed by the manufacturer. Use the data logger to indicate the duration and time intervals at which you wish the data to be recorded.

4. Strike the tuning fork against a surface so that it begins to vibrate.

5. Identify the graph produced by the sound sensor. The x axis of the graph will represent millivolts, while the y axis will represent time.

6. Calculate the period of the sound wave by using the graphing features of the sound sensor to measure the interval between two successive peaks. Make note of this figure.

7. Calculate the frequency using the formula F = 1/T, where "T" is the period of the sound wave. Express your answer in Hertz (Hz).

Tips & Warnings

• For a more precise figure, measure the frequency several times and use these results to calculate an average frequency.

References

• Measuring the frequency of a tuning fork
• Tuning fork
• The Normal Examination and Echocardiographic Measurements; Bonita Anderson; 2004