[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*Subject*: RE: [at-l] I'm confused*From*: "McBride, James" <mcbride_j@lxe.com>*Date*: Tue, 3 Aug 1999 11:57:04 -0400

You are not confused. I didn't check the persons math that gave you the new conversion factor between Joules per square meter, and milliwatt seconds per square centimeter, but I'm sure they are right. The other figure you had was completely wrong. Think about it this way ... we are simply converting SI units which are all related to each other by factors of 10. For example: 1m = 100cm 1W = 1000mW 1W = 1J /s So you see there is no way to get a conversion factor of 16.8 or whatever the number was that you had before. Jim McBride > ---------- > From: David F. Addleton[SMTP:dfa@wimlaw.com] > Sent: Tuesday, August 03, 1999 11:07 AM > To: at-l@backcountry.net; Pete J. Osler > Subject: Re: [at-l] I'm confused > > I must be the confused one. > I just accepted the conversion given me from elsewhere. > At any rate, your figures are better than the ones I used for this issue > since they increase the sun's dose of UV-A and UV-B in my calculations: > > J/M^2 mw-s/cm^2 dose @ 1 minute > 800 80 4800 > 1000 100 6000 > 2000 200 12000 > 3000 300 18000 > 4000 400 24000 > 5000 500 48000 > > instead of > > J/m2 mw-s/cm2 > 800 1.3344 > 1000 1.668 > 2000 3.336 > 3000 5.004 > 4000 6.672 > 5000 8.34 > > The result is to diminish the time necessary for the sun to do its > sterilizing work, using UV-A and -B. It likewise increases the miniscule > amount of UV-C that reaches the ground, esp in high altitudes by the same > amount: > nearly 60 times greater than I had calculated. > > ---------- > > From: Pete J. Osler <osler@btv.ibm.com> > > To: at-l@backcountry.net > > Subject: [at-l] I'm confused > > Date: Tuesday, August 03, 1999 7:35 AM > > > > > 1 joule/square meter = 16.68 mw-s/10,000 sq cm = .001668 mw-s/sq cm > > > > If I remember my high-school physics: > > > > 1 Watt is defined as 1 Joule / Sec, or conversely 1 Watt-Sec = 1 Joule > > > > 1000 mWatt-Sec = 1 Watt-Sec = 1 Joule > > > > 1 Joule / M^2 = 1 Watt-Sec / M^2 = 1000 mWatt-Sec / M^2 ( where '^2' > means 'squared' ) > > > > 10000 cM^2 = 1 M^2. ( where '^2' means 'squared' ) > > > > 1 Joule / M^2 = 1000 mWatt-Sec / 10000 cM^2 = 0.1 mWatt-Sec / cM^2 > > > > ...Pete Osler Ga->Me '81 > > * From the Appalachian Trail Mailing List | http://www.backcountry.net > * > * From the Appalachian Trail Mailing List | http://www.backcountry.net * > * From the Appalachian Trail Mailing List | http://www.backcountry.net * ==============================================================================

- Prev by Date:
**Re: [at-l] Catawba Sickness** - Next by Date:
**[at-l] How about?????????** - Prev by thread:
**Re: [at-l] I'm confused** - Next by thread:
**Re: [at-l] I'm confused** - Index(es):