Talk:Spectrophotometry

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spectroPHOTOmeter is for VISIBLE light[edit]

If you look at the websites of manufacturers such as Perkin-Elmer (both UV/VIS and FTIR) or Bruker (FTIR), you'll see that they reserve the name "spectrophotometer" for UV/VIS/NIR, and use "spectrometer" for IR applications.

Note: the article overlaps with the article spectrometer.

-- Hankwang 09:55, 2 Apr 2004 (UTC)

Thank you for your interest in my changes. I do hope you agree that spectrophotometers can measure reflectance as well as absorption, although I admit that such instruments are rare.

I agree that there is a lot of overlap in various articles, and I hope to be able to resolve some of it, but I think it will take some time. For one thing, I think there is no article yet on photometry as such. That might be the appropriate place to put a discussion of the various ways to measure light intensity.

I think the concept of a spectrometer covers a wider class of spectral measurements than just photometry.

There was a time when I was in the habit of calling a CD instrument a Circular Dichroism Spectrophotometer, but I was gently convinced to change to using the term Circular Dichroism Spectrometer. I found this distinction confusing, especially since CD is measured as a differential absorption. I think in this case the critical distinction is the intention of the measurement, a fine point. So I think it is fair to say that I have been struggling to clarify these concepts for myself for a while. As a consequence, I am grateful for your interest and for your help.

As to your specific objection, I think it is fair to say that UV and NIR are not visible. I did a quick google search and found plenty of hits for IR spectrophotometers. I also believe there is a historical precedent for using the term IR Spectrophotometer. Here is one source: http://www.ossc.org/bios/fellows-hawes.htm This biographical note about Roland Hawes mentions his contributions to the development of the (Beckman) "Models IR-2 & IR-3 Infrared Spectrophotometers". Mr. Hawes played an important role, not only at what became Beckman, but at the Applied Physics Corporation, a leading manufacturer of spectrophotometers, that later became the Cary division of Varian Instruments.

I think it is fair to say that manufacturers use terminology in a way that facilitates sales, and which is not necessarily in a way that facilitates an encyclopedic description. In any event, FTIR is an unusual technique that needs to be differentiated from wavelength domain instruments.

If I had to make the distinction on photometry, I think I would focus on measuring the flux of photons, that is the light intensity, in which case I would accept IR as well.

AJim 17:18, 2 Apr 2004 (UTC)

Color Sample folks please make disambiguous[edit]

Tons of industries use only the visible portion for color matching with spectophotometers, and specrtaradiometrs(poop how do ya spell this word?) ) to measure light sources. Photons and flux are nice, but let's not get off the subject. I want Spectrophotometers as a separate page from what more of the electromagnetic stuff is about on wiki.

There is a pile of crap in Colorimetry I tried to fix up a bit, but it's still a mess.

Dkroll2----

NanoDrop[edit]

A spectrophotometer with cuvettes is an item in teaching labs/underfunded labs. nowadays a good lab a small machine called a nanodrop. The problem is only one company makes it and I do not want to edit this page and make it look like a publicity. Squidonius

So how does it work[edit]

Its kinda important to knwo how it works scientifically, you know...I have a bio lab I need to do!Tourskin 20:36, 10 February 2007 (UTC)

I think one thing that would really benefit the article, and goes with this, would be to get an image of a schematic diagram of one... Can someone please upload a picture of a schematic diagram of one of these that gives some small explaination of how it works? I think that would be a good benefit to the article, but I don't really know how to do pictures on wikipedia... only editing :D Thnx! Cactus Guru (talk) 23:31, 22 September 2008 (UTC) --Navigaiter2 (talk) 04:02, 7 July 2009 (UTC)I fixed these things for five years and I know how they work. It's hard to verbalize in a one-page summary. But I'll be back and try again soonNavigaiter2 (talk)

A red link has been created based on the following....[edit]

http://www.hitachi-hitec.com/global/science/fl/fl_index.html --222.64.222.202 (talk) 09:41, 28 August 2009 (UTC)

Photospectrometer[edit]

What about a "photospectrometer"? This appears to be a (very?) commonly used name, along with photo-spectrometer or photo spectrometer (which make a bit more sense). I can only guess it is an incorrect term - in which case it should go onto a disambiguation page? --Adx (talk) 01:09, 21 December 2009 (UTC)

My understanding of this is that photo spectrometry refers to a device that measures light that has been reflected off a solid surface (as opposed to spectrophotometry, which measures the light that has passed through a liquid). For the former, I use one of these http://www.cherlyncolour.co.uk/khxc/media/gbu0/prodsm/xrit160.jpg in my current place of work, which you simply place on the surface and click down - and it's always referred to as a photospectrometer. It spits out L*a*b* values. For me, this is distinct from the other form, where you have to fill a cuvette(or similar) with liquid. I'm not sure if this is a formal distinction or not though, or even how common this form of measurement is. GGdown (talk) 12:39, 14 December 2010 (UTC)

The sequence of events in a modern spectrophotometer.[edit]

I am currently using a UltraSpec 2100 (BioChrome) https://www.gelifesciences.com/gehcls_images/GELS/Related%20Content/Files/1314723116657/litdoc2100pro_20110830195831.pdf The description of operation is : First the light goes thru a monochromator; then the light is directed at the sample. The detectors are at the the other end measuring how much light came thru. — Preceding unsigned comment added by Shalom25 (talkcontribs) 21:35, 1 December 2012 (UTC)