Use of a digital voltmeter to measure the output of a sound level meter

The use of a digital voltmeter and associated computer program to measure the varying output of a sound level meter is discussed. The computer program converts the voltmeter readings into sound levels and calculates quantities such as $\text{L}{}_{\mathrm{<mtext>10</mtext>}}$, $\text{L}{}_{\mathrm{eq}}$, etc. Using the dc output of a sound level meter, the dynamic range is about 25 dB. This increases to at least 45 dB on the ac output. In general, values found for $\text{L}{}_{\mathrm{<mtext>10</mtext>}}$, $\text{L}{}_{\mathrm{eq}}$, etc. are within 1 dB of results obtained by other methods.