Pressure correction with altitude

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

>Date:         Mon, 30 Mar 1998 16:35:42 -0600
>Reply-To: Medical Physics Mailing List <MEDPHYS@LISTS.WAYNE.EDU>
>Sender: Medical Physics Listserver <medphys@lists.wayne.edu>
>From: "Frank R. Borger_(FRB)" <FBORGER@GAMMEX.COM>
>Subject:      Pressure correction with altitude
>To: Multiple recipients of list MEDPHYS <MEDPHYS@LISTS.WAYNE.EDU>
>
>
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>I found the following in the compton's CD encyclopedia:
>
>        Altitude        mmHg
>
>        0               760
>        3000m   520
>        6000m   350
>        9000m   225
>
>A natural log fit to this data (ln(altitude) vs mmHg,) yielded an excellent
fit, and
>resulted the the following program which will calculate the resultant
fudge factor
>up to 9000 meters. (Extrapolation beyond 9000 meters not recommended.)
>
>        OPEN "c:\prestabl.dat" FOR OUTPUT AS #3
>
>        PRINT #3,
>        PRINT #3, " meters   mmHg    mm/km"
>        PRINT #3, "--------  -----   -----"
>
>        lastpres = EXP(6.633)
>        FOR i = 0 TO 9000 STEP 100
>        y = 6.633 - .0001292 * i
>        press = EXP(y)
>        diff = press - lastpres
>        PRINT #3, USING "  ####    ###.#  ##.###"; i; press; diff/10
>        lastpres = press
>        NEXT i
>
>        PRINT #3,
>        CLOSE 3
>
>
>Frank R. Borger, Senior Support Engineer
>Gammex-RMI, Middleton WI
>608-828-7289 fborger@gammex.com
>
>The opinions expressed here are strictly mine,
>and do not reflect the views of Gammex-RMI.
>