What is the different chemical composition between the standard halophosphate and the deluxe to cause them to have a better CRI? Also, how does the 740 have 10 better CRI than a 640 and still technically, according to:http://www.lamptech.co.uk/Documents/FL%20Colours.htm, be a pure halophosphor?

What is the different chemical composition between the standard halophosphate and the deluxe to cause them to have a better CRI? Also, how does the 740 have 10 better CRI than a 640 and still technically, according to:http://www.lamptech.co.uk/Documents/FL%20Colours.htm, be a pure halophosphor?

I don't know the exact blending ratios, but deluxe tends to extend emissions across a wider range at significant expense of efficacy.  You're looking at 2/3 the output of standard version while using the same amount of power.  For F40T12, CWX, DX, DSGN50/Chroma/Colortone, Vitalite,etc are all in 2000-2500 lumen range while standard CW is around 3300.

I don't know about UK, but in the US, I believe the prefix makes a difference, but they don't usually publish it and if you ask, they'll likely tell you its confidential.  For example, 865 means CRI is between 80 to 89 and CCT of 6500K.

Here, T8 865s are usually RE865.  RE stands for Rare-Earth.
F40T12/DX uses non rare-earth, which are probably halophosphates.
FO32T8/865 uses RE865

Deluxe Halophosphate lamps contain a blend of the ordinary Calcium Halophosphate with tin and manganese activators + magnesium fluoro-germanate with Europium activator.  The latter has a very strong red radiation (it it the same phosphor used in mercury lamps from 1950-1964), and it is responsible for increasing the CRI of Deluxe tubes.

Owing to its strong reddish radiation, if simply added to the ordinary halophosphates it would give the light colour a distinctly pinkish colouration.  However that can be partially offset by playing with the tin:manganese ratio of the calcium halophosphate, which makes that phosphor relatively more blueish or orange.

Since the red light from the germanate occurs at deep red wavelengths to which the eye is not especially sensitive, plus the fact that the halophosphate has to be adjusted to achieve more blue to offset the red germanate, and that blue light also occurs at deep wavelenghts to which the eye is not very sensitive, the efficacy of Deluxe halophosphate tubes is typically only half that of the ordinary halophosphates.

In Europe the Deluxe halophosphates therefore disappeared in the early 1980s when triphosphor tubes were invented.  Those produce strong red light at wavelengths to which the eye is more sensitive, and achieve similarly high CRI values without the efficacy loss.

But early 1980s does not apply to COMECON lamp manufacturers, or?

I recall seeing standard and deluxe cool white ("Neutralweiß" and "Neutralweiß de luxe", respectively) Narva lamps side by side in one fixture. One could clearly note that the latter one put out less light, but of a much smoother colour without the green hue of the standard lamp. Also recognizable was the additional pink content, not as a real hue but still as a component the standard lamp did not have.

Wow James-you know a fantastic amount and thanks to all the other contributors. I was looking around your site and noticed you do not have any spectrums for Deluxe lamps. Is this because no manufacturer ever published them? I must say that a 55 looks almost the same colour wise to an 865 which I saw in an office. Also, Philip's graphica range, is it a mixture of halos and tris because the spectrums seem to mixture of the both?
Thanks again everyone.

Indeed the deluxe spectra are not published very widely.  At least in EU it became standard practice to include the spectra in the catalogues only in the 1980s and by that time the deluxe fluorescents were almost gone.  One exception however is the Thorn catlogue from '69 on my site where you can see some DX spectra.  They are not very detailed though, its on my list of things to do to measure some older fluorescent colours and add these tubes to my site!  I think you are right about Philips Graphica 47, but have never found one of those tubes to be able to see its spectrum in detail.

Thanks James- the thorn catalogue is very detailed. I have been comparing thorn's spectrums with  Philips' modern ones on the 530s, 535s and 640s. The yellow and violet quantities stay the same, just the ~450 nm blue region reduces as the colours get warmer. The Kolor-rite spectrum looks magnificent - shame they're so rare.

Thanks again James for such a magnificent website. Just a comment, on your halophosphor spectrums, you show a massive peak around 570nm and around 400nm. None of the other spectrums show these any where as intense. Is this just Philips' spectrums are wrong or is it your software has over calculated?