# attenuationWater

Calculate ultrasound attenuation in distilled water.

## Syntax

    att = attenuationWater(f, T)

## Description

`attenuationWater` calculates the ultrasonic absorption in distilled water at a given temperature and frequency using a 7th order polynomial fitted to the data given by Pinkerton (1949, The Absorption of Ultrasonic Waves in Liquids and its Relation to Molecular Constitution, Proceedings of the Physical Society. Section B, 2, 129-141). A plot of the absorption at 20degC returned by `attenuationWater` along with the absorption calculated by the corresponding power law given by Szabo (2004, Diagnostic Ultrasound Imaging) is given below.

    % calculate attenuation between 0 and 50 MHz
    f = 0:2:50;                     % [MHz]
    att = attenuationWater(f, 20);  % [dB/cm]

    % plot attenuation and power law
    figure;
    plot(f, att, 'k-', f, 2.17e-3 * f.^2, 'bx');
    xlabel('Frequency [MHz]');
    ylabel('Attenuation Coefficient [dB/cm]');

## Inputs

`f` | array of frequency values [MHz]
`T` | water temperature [degC]

## Outputs

`att` | attenuation [dB/cm]

## See Also

`speedSoundWater`