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RE: Effective Irradiation Dose Unit-UV
Einstein/mm^2 is photon density, i.e., the number of moles of photons per
mm^2, where 6.02x10^23 photons (Avagadro's number) are in one mole. The
unit commonly used today is the mole/m^2. When referring to the 253.7 nm
line the photons are clearly identified, and one can convert to-or-from
energy density in J/m^2 using the energy of the 253.7 nm photons.
In many situations the photons are distributed over a finite spectral band,
and this band must be specified. For example, in photosynthesis the 400-700
nm band is relatively standard. When a finite spectral band is used, there
is not a general conversion to energy since photon energy varies with
wavelength. If the spectral power distribution of the radiation is known,
then an conversion can be made for that particular SPD. Photon flux density
(i.e., a rate of flow) would be in mole/(m^2*s).
Robert E. Levin, Ph.D.
Corporate Scientist
OSRAM SYLVANIA
71 Cherry Hill Drive
Beverly, MA 01915
phone: (978) 750-1594
fax: (978) 750-1794
e-mail: robert.levin@sylvania.com
> -----Original Message-----
> From: Kenneth W. Price [SMTP:75301.361@compuserve.com]
> Sent: Wednesday, April 14, 1999 10:47 AM
> To: Multiple recipients of list
> Subject: Effective Irradiation Dose Unit-UV
>
> Radsafers,
>
> I came across a unit of "effective irradiation dose" for UV in the 253.7
> nm
> region. This unit is the nano-Einstein/mm2. This unit was used in a
> paper published in Biochemistry in 1977. The unit as used in the article,
> relates moles of ATP joined per mole of enzyme. Any info on this unit?
>
> Ken Price, RSO
> University of Connecticut Health Center
> Farmington, Ct
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