Wednesday 30 May 2018

Untitled Post


The Compact Color Medium Pressure Mercury Lamp



Imagine your Light Community outdoor environment lit with egg-shaped big lamps in all the colours available for neon-signs... You have them no where, excepting some coloured metal halide lamps, in certain colors only.

Proposals for research will come into discussion in order to discuss and achieve lighting sources for esoteric purposes.

A web page will be dedicated for discussion. Till then these only are available:


http://lightcommunitylighting.blogspot.com/2018/04/blog-post_13.html

Look here a random example of neon-signs color range:

https://www.custom-neon-signs.com/Colors

Briefly, in order to achieve each of this color with compact egg-shaped mercury lamp, you have mainly to find so:

- a discharge tube to provide the needed amount of UV in order to irradiate the fluorescent coating of the egg-shaped bulb.

- the needed amount (area of bulb) of fluorescent coating to provide the minimal desired lumen output, if proper irradiated with UVs.

- a proper balance between the heat output of the discharge tube and the size of the (egg-shaped) outer bulb, in order to NOT overheat the fluorescent coating,... which in case of neon signs is not so heat-resistant.


This last item might be the most 'dangerous' one. It might be what prevents a proper color to be achieved and the premature damage of the coating.
This is an important item which the research must solve...


NOTICE!
Discussion about the 'medium pressure mercury lamps' (Ar+Hg) do not include the proposed 'medium pressure neon-mercury discharge lamp', which is a case itself.
This one will use for research the 'common' phosphorous coating for HID mercury lamps. It's main light spectrum is expected to come out from the discharge itself, and will be a reddish based spectrum. Let's say from light-cyclamen to violet-red, depending of the balance between neon and mercury (in discharge terms, not in 'weights').



Here some examples of 'medium pressure mercury':
In that catalogues are some 'low power' already existing (so having 'proof of time') UV medium pressure arc tubes, which (at least theoreticaly) may be used for our proposed medium pressure mercury lamps.
If you or other readers are also in knowledge you will immediately say 'yes' or 'not' as your opinion might be...
The item of interest in the catalogue are the 2 400W medium pressure mercury lamps (arc tubes) which burn in any position (not only horizontal):

HP 4/120 400 125 3.5 120 410 31 105 14.0
and
HP 4/120 SE 400 125 3.5 120 410 31 111 14.0
The arc tube is 31mm length and 14mm dia.

They also run at 120V arc voltage and 3.5A, let say 'nearby' the common HID 400W mercury lamp...
What is also interesting in the catalogue are the Medium-pressure metal halide lamps (not used in general lighting), from which the point of interest is that of 460W

HPM 12 460 120 4.1 800 44 98 22.
The arc tube is 44mm length and 22mm dia.

Thus we might to prefer even a lower power one, this one needs however to be taken in consideration.

On the other hand, we might say that the 'medium pressure' is 'missing' from the metal halide lamps 'portfolio'... The case is also for the sodium lamps...
Here a 250W metal halide UV arc tube. However no arc-voltage and amps.

250 5000089 MHL-250 15.5 68 18 300-450

https://www.ushio.com/files/catalog/uv-mhl.pdf

However the medium pressure MH lamps seem to be weak in the 250-260 nm, while the medium pressure mercury ones seem somehow reach.

Give a look to the bulb in this link:
http://www.fisherylight.com/metal-halide-fishing-lamps/2000W-on-boat-metal-halide-fising-lamp.html

It is a so called 'fishing lamp' (in fact a fish lure lamp used for ocean fishing).

But, of course our point of interest is altogether different, you guess it...

It is a big sized bulb, let say 'big as a house', thus it's not even so... :-)

Consider it to have 200mm/8in dia and an E40/Mog screw cap.

Now! imagine instead of its arc tube (of 2000W) one of the arc tubes above described of 400W medium pressure mercury or metal halide arc tube.

And, the more, imagine it coated with the fluorescent coatings in discussion used for neon signs, or as case for fluorescent tubes.

The arc tube is supposed to provide an amount of UVs, enough to irradiate the large area of the inside coated surface of outer bulb.
However, there is the need of sufficient amount of spectral emission in the appropriate wavelengths which properly match the sensivity (in wavelenghts) of the coating, in order to have a convenable conversion work of the phosphorous.

Now it's ready for research! Of course you need access to a plant where this kind of bulbs are currently manufactured. In Asia there are many, many that can do it at a reliable price.


Discussion to come to imagine the experiment...









[Image posted for educational purpose only]



9 comments:

  1. The E33 thread for lamps caps and holders - a product standard for Light Communities development...

    Now, when there is already available a broad mid range of HID lamps, you have not at disposal a mid range size for lamp cap and holder, to fit this range of lamps.

    Mid range HID lamps can use either the E27/Med or the E40/Mog screw-cap and holder. While the first one
    is considered as undersized in many cases, the big one is usually chosen, which of course, is oversized.

    So we bring in for our Light Communities the E33 size to be used for medium power HID lamps, which is expected to be most broadly used, especially in the outdoor environment of the communities.


    http://lightcommunitylighting.blogspot.com/2018/01/e33-screw-caps-and-lampholders.html

    ReplyDelete

  2. http://www.globalsources.com/si/AS/Bueno-Optoelectronics/6008840281896/pdtl/Fishing-Light-Squid-Attractor/1124346620.htm

    ReplyDelete

  3. An example with more specific data of medium pressure mercury lamp:

    https://www.indiamart.com/proddetail/medium-pressure-mercury-lamp-9188621288.html

    Claims are here about a power as low as 125W, 250W, and peaks of UV of 254nm and others.

    "Medium Pressure 250W, 450 W and 1000W cover the UV range from 250nm to 400nm with peaks at 254nm, 356 and 365nm. UV output is approximately 18 -20 percent of the lamp wattage."

    So, in this case the luminophores used to colored fluorescent tubes may work, at least from the point of view regarding the wavelength conversion.

    ReplyDelete
  4. Osram HgH 1000 medium pressure mercury vapor lamp 265W

    https://www.youtube.com/watch?v=gw3lrV6U6tU

    ReplyDelete

  5. HgHS 1000, HgH 1000, Philips SO45, Radium HRL 250, RADIUM HRL delux 250, OSRAM Nitra 200W 225V:
    https://www.lighting-gallery.net/gallery/displayimage.php?album=85&pos=28&pid=149979

    ReplyDelete
  6. As stated above, in order to achieve a colored ED bulb with fluorescent tube coating you need an arc tube to produce the amount of UV necessary for the fluorescent tube phosphorous.
    If we presume that these kinds of phosphorous are very sensitive to the UVC around 254 nm, you have to find a HID arc tube to emit these radiation in a sufficient amount.
    If you are a specialist, you know that the high pressure mercury discharge is poor in these wavelength, so it is not an option. But you also know that a lot of UV medium pressure mercury lamps emit a broader spectrum of UV light with higher intensities between around the 254 nm (which is characteristic to the low pressure mercury discharge), so it might be an reliable option.
    So, if we want to start a research on the subject, we have to put on the research desk, let's say, - the medium pressure mercury arc tube of the lowest power, but which provide the greatest amount of UV around 254 nm.

    ReplyDelete
  7. The outer bulb (see image above) has to be at least one size larger than that corresponding to the same power of high pressure lamp;
    i.e. for 125 W medium pressure the outer bulb has to be of ED28/ED90 size; for 250 W it has to be of ED/BT37,ED/BT120, while for 400/450 W it has to be of ED145/BT46/BT150.

    ReplyDelete