Talk:Spectrophotometry/Archive 1

Archive 1

spectroPHOTOmeter is for VISIBLE light

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

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

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

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....

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

Photospectrometer

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.

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 (talk • contribs) 21:35, 1 December 2012 (UTC)

History

The claim that the spectrophotometer was invented in 1940 is incorrect. Spectrophotometry was a technique used throughout the first half of the 20th Century. If we are discussing the history of the spectrophotometer and not the technique, which is misleading itself, Arthur C Hardy's spectrophotometer was on the market in 1935. — Preceding unsigned comment added by 2601:184:4780:94AD:BD2A:8081:FD20:2D59 (talk) 21:35, 19 June 2018 (UTC)

The dude above is correct that Arnold Beckman did not invent the spectrophotometer. However, he should be mentioned on this page as one of the fathers of the field. Arnold Beckman's revolutionary innovation was creating the first mass produced retail spectrophotometer. He turned a relatively obscure, expensive, and custom built scientific apparatus into a reproducible commodity that could be purchased as a finished product. Science Is My Life (talk) 02:29, 4 April 2021 (UTC)

A Commons file used on this page has been nominated for speedy deletion

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• Single beam array scanning spectrophotometer.jpg

You can see the reason for deletion at the file description page linked above. Community Tech bot (talk) 15:06, 4 July 2018 (UTC)