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Metal Halide - Ceramic
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Updated 27-IV-2019 |
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The possibility of employing ceramic arc tubes for metal halide lamps is not a new idea - indeed their use was proposed in the earliest patents on metal halide lamps back in the 1960's. Their potential advantages were recognised even at that time, in that they are more resistant than quartz to the corrosive nature of the metal halide salts within the arc tube. In addition they can operate at temperatures beyond which quartz begins to soften. Ceramics thus offer the possibility to increase the loading in the arc tube, bringing about an increase in wall temperature, which in turn increases colour rendering properties and luminous efficacy.
However while the ceramic arc tube itself is more resistant to halide corrosion, the same cannot be said of the end seals where the metal lead wires pass through the ceramic. The end seals must be kept at low enough temperatures to reduce the rate of corrosion, and traditional metals known for ceramic to metal seals cannot be exposed to the halides.
The first practical solution to this problem was developed by Thorn Lighting in England during the early 1980s, and in 1981 that company exhibited the world's first Ceramic Metal Halide lamp at the Hannover World Light Fair. This so-called 'TSH' lamp is illustrated below, and employs electrically conductive cermet caps to close the ends of the arc tube and make a halide-resistant seal. The unique molecular spectrum of the tin chloride dose also resulted in rather good colour properties for its time. But the marketing division did not take the idea further, since this lamp required a special kind ballast that was not available.
The commercial introduction of ceramic lamps had to wait until 1994 when Philips unveiled its 'CDM' range having the 'Protruding Plug' kind of end seal. In this approach the seal is displaced some distance away from the heat of the arc tube, thus bringing its temperature down to safe limits. An ingenious arrangement of different metallic conductors is contained within the seal both to ensure halide resistance and prevent cracking of these delicate seals. All subsequent lamps are based on this and later variants of the protruding plug seal. |
| | Early Prototypes and Experimental Lamps |
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![](Images/HID Thumbnails/t D MHC Thorn MBIT250 Corstar.jpg) |
Thorn |
250W |
Very early experimental sapphire metal halide |
~1975 |
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![](Images/HID Thumbnails/t D MHC Thorn TSH150.jpg) |
Thorn |
150W |
TSH Tin Sodium Halide with Cermet seals |
~1981 |
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![](Images/HID Thumbnails/t Thorn TSH150 Corstar.jpg) |
Thorn |
150W |
TSH Tin Sodium Halide with Corstar arc tube |
~1981 |
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![](Images/HID Thumbnails/t Thorn CMH70.jpg) |
Thorn |
70W |
CMH Ceramic Metal Halide with cermet seals |
~1983 |
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![](Images/HID Thumbnails/t Toto YAG70.jpg) |
Toto |
70W |
CMI-T with Transparent YAG ceramic arc tube |
~1999 |
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| | Compact Single-Ended Lamps |
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![](Images/HID Thumbnails/t Philips CDMT35.jpg) |
Philips |
35W |
CDM-T Mastercolour 5pc extruded arc tube |
1994 |
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![](Images/HID Thumbnails/t D MHC GE CMHT70-830 5pc.jpg) |
GE |
70W |
CMH-T ConstantColor 5pc extruded arc tube |
1997 |
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![](Images/HID Thumbnails/t D MHC Osram HCIT35-WDL 5pc.jpg) |
Osram |
35W |
HCI-T Powerstar 5pc pressed arc tube |
1997 |
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![](Images/HID Thumbnails/t D MHC Sylvania CMIT70WDL 1pc-cylindrical.jpg) |
Sylvania |
70W |
CMI-T Metalarc 1pc slip-cast arc tube |
1997 |
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![](Images/HID Thumbnails/t D MHC GE CMHT150-830 3pc.jpg) |
GE |
150W |
CMH-T ConstantColor 3pc injection-moulded |
1999 |
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![](Images/HID Thumbnails/t GE CMHTC20.jpg) |
GE |
20W |
CMH-TC first 20W lamp 3pc thin-wall arc tube |
2001 |
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![](Images/HID Thumbnails/t D MHC Osram HCIT150WDL Powerball.jpg) |
Osram |
150W |
HCI-T Powerball 2pc injection-moulded |
2003 |
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![](Images/HID Thumbnails/t D MHC Philips CDMT70-930 Elite 5pc.jpg) |
Philips |
70W |
CDM-T Elite Dimmable 5pc extruded arc tube |
2005 |
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![](Images/HID Thumbnails/t D MHC Osram HCITC70-930 Powerball Shoplight.jpg) |
Osram |
70W |
HCI-TC Powerball Shoplight high CRI |
2007 |
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![](Images/HID Thumbnails/t D MHC Philips CDMTC35-930 Elite 2pc.jpg) |
Philips |
35W |
CDM-TC Elite 2pc cylindrical arc tube |
2007 |
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![](Images/HID Thumbnails/t D MHC Philips CDMT100-930 Elite 2pc.jpg) |
Philips |
100W |
CDM-T Elite 100W 2pc ellipsoidal arc tube |
2010 |
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![](Images/HID Thumbnails/t D MHC Philips CDMT70-930 ELB.jpg) |
Philips |
70W |
CDM-T Elite Lightboost Unsaturated Dimmable |
2011 |
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![](Images/HID Thumbnails/t D MHC Osram HCIT70-WDL Powerball RF.jpg) |
Osram |
70W |
HCI-T Powerball non-radioactive design |
2011 |
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![](Images/HID Thumbnails/t D MHC Philips CDMT70-930 Evo.jpg) |
Philips |
70W |
CDM-T Evolution Ultra high efficacy |
2017 |
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| | Double-Ended Lamps |
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![](Images/HID Thumbnails/t Philips CDMTD150.jpg) |
Philips |
150W |
CDM-TD Mastercolour double-ended |
1997 |
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![](Images/HID Thumbnails/t KK CDMTD150.jpg) |
KK Light |
150W |
First Chinese Ceramic Metal Halide |
2002 |
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| | Screwbase Lamps |
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![](Images/HID Thumbnails/t Philips CDME70.jpg) |
Philips |
70W |
CDM-E Ellipsoidal Fluorescent for U.S.A. |
1994 |
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![](Images/HID Thumbnails/t Iwasaki MT150CEW with box.jpg) |
Iwasaki |
150W |
Ceralux MT150-CEW with Cermet end seals |
2002 |
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![](Images/HID Thumbnails/t GS CMH230.jpg) |
G.S. |
230W |
Lamp of Japan Storage Battery Company |
2001 |
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![](Images/HID Thumbnails/t Philips CDM400.jpg) |
Philips |
400W |
HPS Retro-White High Wattage CDM |
2001 |
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![](Images/HID Thumbnails/t Osram Powerball HCI-T250.jpg) |
Osram |
250W |
HCI-T Poweball 2-Part elliptical arc tube |
2002 |
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![](Images/HID Thumbnails/t GE CMH-TT 250W.jpg) |
GE |
250W |
CMH-TT 250W / 830 Single Piece Arc Tube |
2003 |
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![](Images/HID Thumbnails/t D MHC Sylvania Relumina 85W.jpg) |
Sylvania |
85W |
Relumina 85W Retrofit for 125W Mercury |
2015 |
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| | Reflector Lamps |
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![](Images/HID Thumbnails/t Philips CDMR30.jpg) |
Philips |
35W |
Mastercolour CDM-R PAR30 Reflector |
1997 |
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![](Images/HID Thumbnails/t Philips CDMR111.jpg) |
Philips |
35W |
Mastercolour CDM-R111 Aluminium Reflector |
2003 |
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![](Images/HID Thumbnails/t GE CMH20 MR16SP.jpg) |
GE |
20W |
CMH ConstantColour MR16 Spot Reflector |
2005 |
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![](Images/HID Thumbnails/t Philips CDMRi 25W.jpg) |
Philips |
25W |
CDMR-i Self Ballasted Reflector Format |
2005 |
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