disp(' ');
disp(' SPL_change_ambient.m  ver 1.0  April 9, 2009 ');
disp(' by Tom Irvine  Email: tomirvine@aol.com');
disp(' ');
disp(' Reference: ');
disp(' L.C. Sutherland, Sonic and Vibration Environments for ');
disp(' Ground Facilities - A Design Manual, Prepared for NASA ');
disp(' by Wyle Laboratories, Report WR 68-2, Huntsville, AL 1968.');
disp(' See Chapter 7');
disp('  ');
P=input(' Enter pressure (mm Hg) ');
disp(' ');
C=input(' Enter Temperature (deg C) ');
disp(' ');
K = C + 273;
%
Pr=P/760;
Tr=288/K;
%
CA=10*log10(Pr^2*Tr^4);
%
out=sprintf(' CA = %8.4g dB \n',CA);
disp(out);