Why the NE/H operates at higher temperature than fluorescent lamps? It have a neon gas, not liquid or amalgam mercury to vapourize?

This is about 1200mm long lamp, with T12 tube. So pretty much the same size as a F40 lamp.
But the F40 has to dissipate 40W in it. This puppy has to dissipate 400W, so 10x more heat than the F40. So while the F40 operates slightly warm, 10x higher power will make it scorching hot (my guess at least in the 200..300degC ballpark) even with optimal cooling in the horizontal position. Not much room left for the things like end caps and their cement, or for the internal structures outgassing and so ruining the inner atmosphere. Burning it vertically the temperature may easily rise further 200..300degC, that means reaching 400..600degC. That is very considerable difference...

This is what James has to say about the lamp. 

Medved is right.  On top of that, the fluorescent lamp converts almost 50% of the input electrical energy into radiation, whereas this neon discharge has only about 10% efficiency.  So the heat generation is even greater again.  Having said that, the speed of the convection currents in neon is not so significant and this gas also has rather high viscosity, so the convection currents are limited.  It could even be that the Langmuir sheath diameter in low pressure neon is not so much thinner than the internal diameter of the glass tube, further restricting internal gas flow (for instance in helium-filled T5 and T8 tubes there is no gas circulation when burned vertically). 

There would of course be a change in the heat losses to the atmosphere due to the presence of the Langmuir layer of stationary gas in the air surrounding the lamp.  A vertically burning lamp would therefore lose slightly less heat to the surroundings as horizontally - in exactly the same way that an incandescent filament that burns vertically within a glass bulb suffers less heat loss than a horizontal filament (hence the development of the high efficacy USA style lamps with superior vertical filaments).

Due to these considerations I am not convinced that vertical burning would necessarily be detrimental to performance, but now I am curious.  Short of building a mathematical model of this lamp in software like COMSOL Multiphysics, a quick and easy way to find out would be to burn this lamp both horizontally and vertically and check the glass surface temperature distribution with a thermal imaging camera.  If there is not so much difference, one possibility is that the inventors called it an NE/H lamp only because the fixtures are typically designed to burn the lamps horizontally.  It would be mechanically and optically challenging to floodlight a building with vertically mounted lamps, which may also present undesirable shadowing of architectural features.

Hello James,
thank you for clearing this up!

You said neon viscosity is rather high? Is there an easy explanation of how viscous a gas is?

Best regards,

Alex

As an outsider myself (not employed nor educated in lighting fields) I welcome some of dor123's inquiries. I truly enjoy reading expert explanations to simple, apparently inane questions, for which I don't have to ask. So thanks for the explicit descriptions.

Further to my initial reply I had a feeling that dor123 might be correct here, and on to something interesting which deserved further investigation rather than rubbishing his ideas.  I am fortunate to work in a lab where it is possible to analyse almost any aspect of light source design, operation and performance - so this week I took one of these old neon lamps in to work to carry out some tests.  The results can be found here.

I hope these new findings might encourage us all to be a little kinder towards each other and realise that none of us know it all.  We all ask stupid questions sometimes, and many give answers that they believe to be correct but in fact are not.  In my experience, some of the greatest new developments we ever made originated from what initially seemed like mad questions - but when we spend some time to think about it and carry out some tests, these can lead to new and valuable knowledge.  So I am grateful that this question was asked.  I didn't know the answer before and it seems that none of us here really did, and I would maybe have never thought to ask such a question.  Thanks to the existence of LG and the fact that enough of us still choose to come here despite the occasionally unfavourable personal interactions, an important question has now been answered :-)

So I think the only thing that needs to stop here is the persistent aggression of certain members against some of the more inquisitive younger contributors who are trying to learn.  It continues to disappoint me that despite the helpful addition of clear rules and regulations introduced by some LG admins, which I hoped might stop such kind of behaviour, there are still frequent attacks that make me feel uncomfortable here.  This is really damaging the reputation of LG and continues to drive away members to alternative lighting groups that present a more friendly and welcoming atmosphere - but unfortunately lack the otherwise excellent structure and organisation of LG.  My wish is for LG to be able to welcome all, and to bring back some of the members and interesting discussions that have now been lost and diffused across multiple alternative platforms.

Thank you for the interesting explanation, James. I won't discuss dor123's questions or behaviour here, but I will ask that if you (or anyone else) have any concerns about the site to make them known either to me directly or to the team in private and we can look at them and see if we can work out a way forward. I don't like the way the site is at the moment any more than you do, but for things to work out, we all need to work together. This includes wording questions in such a way that they aren't seen as stupid. Before hitting that 'Enter' or 'Send' button, think about what you're about to post. Once it's out there, it's not going to go away and like it or not, people will judge you on what you've said.

Hello,
there a few things i want to point out. I think everyone here is right.
First of all this part of my previous comment

  It took me some time to write this. the conversation "evolved". While I would generally consider things like the bang head picture as spam however -sadly- it is adequade here.

Is false and should never been posted. I therefor apologise, especially to the author.
The following should have worded differently:

The topic was about why a noble gas filled lamp may always be able to be burned universal. The argumentation did not work out. That argumentation collapsed. Then it was stared to compare it to a fluorescent lamp, that failed due to the text above. The loading of a fluotube is different than the loading of the Ne/H lamp.

So I think the only thing that needs to stop here is the persistent aggression of certain members against some of the more inquisitive younger contributors who are trying to learn.  It continues to disappoint me that despite the helpful addition of clear rules and regulations introduced by some LG admins, which I hoped might stop such kind of behaviour, there are still frequent attacks that make me feel uncomfortable here.  This is really damaging the reputation of LG and continues to drive away members to alternative lighting groups that present a more friendly and welcoming atmosphere - but unfortunately lack the otherwise excellent structure and organisation of LG.  My wish is for LG to be able to welcome all, and to bring back some of the members and interesting discussions that have now been lost and diffused across multiple alternative platforms.

I see it as well and I am aware that I do it myself. Personally I put a lots of value in politeness and that is clearly contradictory to some things I said here. I should really make sure that I treat everyone equal independent of their experience.
I equally think that more knowledgable members need to share their knowledge. And even more formulate things they are unsure of in a way that the other can understand it that they are unsure. However the receiving part of the knowledge also need to work with it trying to understand it and to apply it to individual topics. That takes a long time and is tidius. I would by far not see my self as an expert, I never worked in the Lighting industry nor do I plan to do so. I learned most of my knowledge from listening to others and asking questions. And I value every challenge, every demand. I think that does not become clear enough. I am sure most other members here does it as well. Questioning answer and raising (simple) questions is how knowledge works. Nobody knows it all ––Nobody is science!––
.
I think a lots of micro aggression here (––at least for the one of my part––) comes from how we communicate not what we communicate!  I have to work on it myself I know, but maybe we should all accept a few basic rules.

––don´t think the other is dumb
–– don´t think your better then the other
––Ask a question the way you want to be asked. Please and thank you are awesome words. That let the other know you appreciated their answer even if it may have corrected you.
––think about how you write a text. The wording may not change the information in it but how people see it.
––do not write more then you know. Uf you are unsure tell it. this maybe the most difficult one in my eyes. I find it hard to knowledge that you do not know things, especially if they seem very simple. I for example learned in Englisch as well as german class (which is my natural language) that I shall always present my thoughts as facts even though I am unsure. In my Opinion a very risky stunt... This thread is a good example non of us knew it. If you guess you need to tell it like. Formulations involving the words would or I think may be helpful.

Regarding this site, I see the problem that people disappear or reduce their activity. I did it as well. However at the moment I am very active again. I see that we give other knowledge to others. Therefor it is good we have members with so much different levels of knowledge ad area of expertise. I understand however the thin line between keeping a certain clima of respect and post quality and the inclusion of all members. I think we all need to give a compromise here. And I see future for this site. For example it was able to have a very nice and kind discussion on this post

Last I want to encourage everyone, if anybody sees a comment of mine he disagree with or in his eyes are formulated offensive or with subliminal micro aggressions, contact me. I don´t bite! I also make errors. I want also to say that I am open to work or talk with the administration on tis and other topics. Again the sentence previous sentence applies.

Best regards,

Alex

This is about 1200mm long lamp, with T12 tube. So pretty much the same size as a F40 lamp.
But the F40 has to dissipate 40W in it. This puppy has to dissipate 400W, so 10x more heat than the F40. So while the F40 operates slightly warm, 10x higher power will make it scorching hot (my guess at least in the 200..300degC ballpark) even with optimal cooling in the horizontal position. Not much room left for the things like end caps and their cement, or for the internal structures outgassing and so ruining the inner atmosphere. Burning it vertically the temperature may easily rise further 200..300degC, that means reaching 400..600degC. That is very considerable difference...

The above was wrritten with the assumption the convection is the dominant way of cooling things down in the air unless they are really red hot.
 
Well, a quick attempt to calculate just the radiated power had shown with the 360W dissipating from the 0.15m^2 surface (about what this tube makes) yields temperature around just 200degC. With a simplification of unity emission coefficient, but also completely neglecting any convection.
So this means the assumption of "radiation could be neglected" was completely wrong (in the terms of at which temperature the heat radiation starts to play a significant role).

What an honourable and delightlful reply!  I know that I have also made similar mistakes in the past, unfortunately far too long ago to find again and be able to improve.  Although my response did take this thread rather off-topic for which I apologise, I do prefer to avoid secrets and keep discussions in the open.  Experience has taught that the private messages really have little effect at the necessary level.  Some members continue to leave us, and other lighting resources are growing stronger at our expense.

A long time ago another of our former frequent contributors (Globe-Collector) helped me understand this situation, with his memorable re-introduction to the Dunning-Kruger Effect.  That is a psychological learning curve which plots Experience vs Confidence.  It applies to all of us and is rather well illustrated here:


In the beginning when we learn any new subject, we all start with zero competence and as such have little confidence.  Some people just aren't interested in learning, and will remain at that level.  Others proceed to acquire a small amount of knowledge, and naturally this results in rapidly increased confidence.  Such people will begin to answer each other's questions as if they know what they are talking about - but invariably don't actually understand the half of it and will give misleading answers and ask what seem like ridiculous questions.  This phase is known as the Peak of Mount Stupid.  Different people suffer this to varying extents and for different lengths of time.  Some of the most dangerous managers I ever encountered at work had clearly got stuck at that point, and such people are superbly illustrated in another wonderful article from Sylvania's former R&D Director John Waymouth - author of the revered book "Electric Discharge Lamps".  If you have time to read his article to its conclusions about corporate management, see here.

Anyway, nearly everyone who persists with their learning then comes to the realisation that in fact the subject is a lot more complex than they initially thought - and they begin to recognise just how little they actually know.  Despite increasing knowledge, their confidence tumbles and leads them into the Valley of Despair.  Such people are enthusiastic and still want to learn but are scared by how much knowledge still has to be acquired.  Eventually we all pass through this phase, and only afterwards do we genuinely begin to learn valuable information, and become more competent and confident.  This is a necessarily slow process.  It can take a whole lifetime to reach the peak of our productivity in terms of knoweldge.  And unfortunately it doesn't end there - because old age then sets in, and with it comes forgetfulness which distorts our earlier memories and we become once again less confident despite having previously acquired a marvellous rich knowledge!

During my academic studies I loved the science and hated all the psychological and philosphical stuff that we were forced to learn (and then quickly forgot).  Such as the importance of this Dunning-Kruger curve, which I had heard of 25 years before I was eventually reminded of its importance, again thanks to contacts made via LG.  Only after several decades I begin to realise that actually, to be effective at what we do, we all need to have a better understanding of the psychology of how people work and how to maximise their own chances of learning.  An understanding of phenomena like Dunning-Kruger can help us become more tolerant and welcoming.  It is nobody's fault if we think they got stuck at the peak of mount stupid because years ago, we all passed through that phase.  Instead it's our responsibility to help them learn enough to pass as quickly as possible through both that phase as well as the valley of despair.  The problems on an international forum like LG are also compounded by language differences.  English is a wonderfully broad means of communication, but completely lacks the depths of many of the emotions and interpretations that are built into the languages of some of our other members.  Typical translation tools still fail dismally to capture their actual meanings.  What might seem like blunt or rude statements are often anything but that.  So rather than putting the onus on the writer to compose messages in impeccable English, I find it helps if the reader always considers that perhaps the words we are seeing might not actually be the same as people would state in their own languages.  We should try to look past that before reacting too negatively and focus on the technical content - while at the same time recognising that none of us here know it all, and that a lot of what we all think we know is actually still fundamentally flawed.  Sometimes I cringe when I read my own responses of just a few years ago, and recognise how easy it is to speak with apparent confidence but now see that I really didn't understand what I was talking about back then!

Excellent comment James! the Dunning-Kruger effect is certainly extremely relevant in the workplace (academic and other) and there is no doubt that it also applies to communities such as LG. I won't go deeper in this fascinating subject as you have covered it thoroughly enough. I'm just chiming in to mention that beside the present issue with language and the proper conveyance of meaning, there is another, perhaps more critical one, i.e. the fact that we do not evolve equally fast along this experience-confidence curve when exposed to knowledge and experience.

While knowledge and experience is definitely not lacking in this diverse community that LG is, the utilization of this valuable resource differs greatly across the vast spectrum of LG users. While some (most) grow very quickly from their own mistakes and mature thanks to other's insights and corrections, others are (much) slower in that process. Some individuals are even immobile and remain stuck in "mount stupid", either because of cognitive impairments or some disability, or because of sheer laziness. If you combine that with a complete lack of social abilities from some, which results in a way of communication that can be qualified as arrogant or "know it all", as some would say, then it's not so difficult to understand why some LG members are getting under the skin of a groups of others. Especially when some situations have remained unchanged after years of interactions between members.

Although this is deplorable situation, efforts must be done both ways if a perennial solution is to be found... unilateral efforts will work only temporarily as patience usually wears thin over time for people who are unwilling/unable to change. If some people must be more accepting, others must also make more efforts to change (or at least be willing to do that). That's how extrema in a statistical distribution applied to a group of people is to be dealt with, especially when a relatively small group of people is concerned. Addressing only one end of the distribution will only results in a skewed distribution with an unequal demand of efforts required to make things work... and such situation never ends well.

I apologise if my posting of the 'Bang Head Here' sign was taken in the wrong way, I was just venting my frustration over the OP not waiting for a reply from James, Max or somebody else equally knowledgeable on why the lamp was designated Ne/H. 

As it turns out it is possible for the lamp to be burned vertically, but the manufacturers deemed it to be for horizontal burning, and if it's good enough for them, then that's what we'll do when we get ours in a few months time. 

Ok, I think this thread is approaching its conclusion now, so I won't say much more, except that in my personal opinion (and it is exactly that, the opinion of Ria the member not necessarily Rommie the admin), if someone (and that could be anyone, I make no distinctions) makes what I consider to be a stupid comment or statement and sticks to that even though they have been told by someone who knows better than they do and has been proven to know better than they do, then as far as I'm concerned they are stupid and will remain so unless and until they prove to me that they are right and I am wrong.

As far as this lamp is concerned, I will echo what Sammi just said. For whatever reason, the manufacturers deemed it to be for horizontal burning and labelled it as such. If anyone wants to experiment with one and see whether it will work in another position, then that's entirely up to them, and I won't tell them they're wrong to do so with their own lamps. But as far as Sammi and I are concerned, if the lamp is marked /H then in the /H position it will be used, and that's an end of it.

Let's calm down and get back to enjoying the hobby and not taking swipes at each other, shall we..?   

I think breaking it down, the main issue so to speak is not the asking of the question, it is a good valid question! we dont want to discourage the asking of questions!



but I think the problem lies with how members can sometimes unfortunately state things as hard facts without actually thinking about it/looking at what is in front of them "is this fact I have applicable to the lamp in front of me or not"

for example in this very first post Dor states

"Why the British neon floodlight lamps were called NE/H, if they can work in any position (They have gas, not metals)?"

the question itself is valid, but the way its stated "if they can work in any position" thats a statement of fact without actually having anything to back it up so to speak is I think what most people on here get annoyed by

not the questions per-say, but the incorrect hard statement of "fact" if that makes sense! for example before the tests by James where conducted,

where was it stated that they can work in any position? the manufacture does not explicitly state it so its not something I would state as fact even if I suspected it true,

I would state it such as "i cant see any reason why it cant burn vertically, thus it would be interesting to know if it indeed can or if there is some other technical aspect that I am not aware of that would restrict its burning position"



another example of this is in my 1500W GE sports star upload where a comment states the lamp must be run horizontally, and the person keeps stating such, even after I provide the data sheet which says its actually most happiest in the vertical position

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-201174

and its this sort of thing, this hard statement of facts, often times completely not applicable to the lamp in question, is what tends to annoy people, but again its not the questions! I dont want people to stop asking questions because they are worried people will get annoyed

its only when comments like as seen on my link above happen, that I think is what annoy people the most!

Yeah, I agree that there's nothing wrong with asking questions but as others have mentioned, HOW you ask a question can have a dramatic effect on how it's perceived by other people. This is especially true on a medium such as LG where all interactions are text based as opposed to voice. video, or in person. People are less happy to answer a question that's worded in a way that could be perceived as rude, or accusatory compared to one asking the same thing but in a more polite and respectful manner. The phrase "You can catch more flies with honey than with vinegar". The question itself could be valid, but if people see the initial post as rude and accusatory, some might move on from the thread and not bother to answer, some might get annoyed and will reply in a similar manner, etc.

I don't think it's wrong to speculate on things you don't know but a lot of people get annoyed when it's presented as a hard fact instead of a speculation. The is particularly true for lamps that you might not have direct experience with, such as lamps you don't have or lamps from another geographical location that you might not be as familiar with compared to ones in your native country. Simply wording statements as "I think this happens because (explaination)" I think will annoy people a lot less.

Finally another thing worth mentioning is repetitively mentioning a fact, even one you can back up will tend to get boring and annoying over time. Personally if I feel the need to inform about this then perhaps mention it once in a comment or make your own thread about it, then move on from the topic in other threads. Most members that have been here for a while will have already seen it at least once it's mentioned so mentioning it often gets repetitive and causes people to get frustrated and tune you out. As mentioned before comments about the burning position of MH lamps seen to be a common one for it, especially when they're often in contrary to what the manufacturer says. Other comments in a similar vein would be the comments I see about the capacitor in CWA ballast circuits, or comments I see regarding HPF and LPF fluorescent ballasts. While they might be true, seeing another comment about those topics for the 10th time gets boring really quickly.