Photo Gallery

MA/V outer pressure

This is my MA/V 400w lamp under an external field to show the outer gas is at low pressure. It may also be just possible to see the gap in the start resistor lead.
Keywords: Lamps

MA/V outer pressure


This is my MA/V 400w lamp under an external field to show the outer gas is at low pressure. It may also be just possible to see the gap in the start resistor lead.

carbon.jpg Thorn_MB21U_400W_-_UK_1969.jpg Mmedp.jpg _IMG2041.jpg _IMG1977m.jpg
Lamp/Fixture Information
Manufacturer:Osram
Model Reference:MA/V
Lamp
Lamp Type:medium pressure mercury
File information
Filename:Mmedp.jpg
Album name:Tuopeek / Mercury Vapour
Keywords:Lamps
Filesize:284 KiB
Date added:Dec 14, 2024
Dimensions:2400 x 1479 pixels
Displayed:25 times
DateTime Original:2024:12:14 21:27:08
Exposure Time:1/60 sec
FNumber:f/4.8
File Source:Digital Still Camera
Flash:No Flash
Focal length:38 mm
ISO:12800
Model:NIKON D3400
Software:Adobe Photoshop Elements 2.0
White Balance:0
URL:https://trad-lighting.net/gallery/displayimage.php?pid=611
Favorites:Add to Favorites

Comment 1 to 5 of 5
Page: 1

Sammi   [Dec 19, 2024 at 06:54 PM]
Yep, can just see that. Wonder
Ria   [Dec 19, 2024 at 10:18 PM]
Zooming in, it looks like there's a faint whisker of wire just making the link Wonder
Max   [Dec 20, 2024 at 12:10 AM]
Very nice! I really had no idea that pressure could be that low in the outer jacket of this lamp type, which now makes me wonder if that outer atmosphere ever reaches 1 atm during operation as I had always assumed. Maybe the reason for a low-pressure outer fill is to ensure a reasonably homogeneous temperature distribution of the large glass burner during operation in the vertical position...

That being said, Crompton's MA lamps had an outer jacket at atmospheric pressure for sure due to their open design... which raises the question of their real performances compared to MA lamps with partially evacuated sealed jacket.
Tuopeek   [Dec 20, 2024 at 07:20 PM]
That's an interesting point about pressure change from cold to hot. Hopefully there isn't much of a chance for a discharge to occur in the jacket with a hot restart. Yes, I also have wondered about the efficiency of the Crompton MA lamp, although I have always question the design of this lamp, as it 'breaths' with thermal cycling creating a slow build up of deposits on the inside where that can't be removed. I can't imagine not sealing off this lamp saved much in manufacturing.
Ria, how much the resistor is hanging on depends on the viewing angle, I'm fairly sure at some angle it looks like a tiny break.
Max   [Dec 31, 2024 at 09:53 AM]
Dirt buildup was certainly a problem in those Crompton lamps. As for the risk of flashover in hot MA lamps, I wouldn't worry too much about that as the pressure increase would not result in any change of gas density in the sealed outer jacket, so the resulting (glow) discharge properties should remain quite constant.

Comment 1 to 5 of 5
Page: 1