Building the electronics of a simple spectrofotometer it's easy if you
have the optics. First you have to define clearfully the optical range
(visible, UV, infrared)
and the sensitivity. Then you have to decide if will be with one or two spo=
ts.
One spot will make easy your life but will increase errors regarding
the probe alignement during calibration/measuring sequence.
 One important aspect is choosing the optic style (difraction plate,
prism, etc) and the dimension of cuvettes for the probes (which
determine the spot dimension also).
 One easy sollution is to buy the difraction chamber and the
photodiodes assembly (there are up to 1024 diodes, capturing the whole
visible spectrum once)
or to build your own detector and amplifier (which is quite easy for
lightwave between near infrared ~900nm to blue 400...430nm) and make
yourself the wavelenght monocromator assembly. The problem here is the
alignement of wavelenght, you must have a good reference source for
this job, or at least a set of interferential filters with very low
bandwith (which is difficult because filters below 5...10nm bandwith
are hard to found)
 I've modified in my life about 10 or maybe 20 proffesional optical
spectrum analyzers made with Karl Zeiss optics in the old time between
'65 to '75.
You can't see anymore such jewels.
 The microcontroller side is just the end of the job, because if you
don't have an excellent analogic design, the rest could be unusefull.

success,
Vasile



On 6/22/06, G=F6khan SEVER <gstr2005@gmail.com> wrote:
> Hi,
>
> In this summer break we are plannig to develop a spectrometer in our
> university. Although i've some emdedded design knowledge and experience i
> havent produce any biomedical devices previously. From now on i want to
> determine a solid thesis subject on biomedical area.
>
> Probably some of the PIClist members had been developed similar devices
> before and should be many members that are knowledgable on biomedical des=
ign
> field. So, Could you please guide me some on this diverse variety field to
> find my way?
> --
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