|Powerstar HCI-T 70W/WDL
|Industrial High CRI lighting
|Arc Tube Length:
|Inner: Quartz. Outer: UV-Stop Quartz
|Colour Rendering Index:
|Peak output wavelength:
|Total light output:
|6,200 Lumens - 89 Lm/W
|3 Minutes/approx 5-15 minutes dependant on ballast type
|Place of manufacture:
|Date of manufacture:
|Not known, code .q828 shown on lamp cap
While ceramic metal halide lamps had been envisioned right from their early days in the 1960s, it was only relatively recently that a product making use of this technology made it to market. This is because while ceramic materials are far more resistant to the corrosive nature of metal halide salts and can operate at far higher temperatures than quartz (allowing the vapour pressure - hence colour rendering index and lamp efficacy to similarly be improved), coming up with a solution to sealing the metal lead wires into a ceramic arc tube that was resistant to attack by the halide salts was a difficult problem to reliably solve. It took until the mid 1990s for Philips to finally come up with a practical solution to the problem. Virtually overnight this opened up an entire new segment in the discharge lighting market for these new lamps.
Interestingly, rather than keeping the secrets of how they had made this technology work close to their chest, Philips instead entered into a patent exchange agreement with most of the major lamp makers, thereby allowing them to develop and bring similar products to market - such as this example from Osram, which is largely identical to the Philips products of the same ratings.
This type of lamps produces an exceptionally good quality of light and sees far less variance in colour between lamps and during lifetime than quartz types. The only real challenges they have faced have been relatively high costs both of the lamps and the control gear compared to halogen incandescent lamps where existing systems are in place - though they did become quite popular in commercial settings where the power savings and reduction in maintenance compared to incandescent lamps would soon mount up. Generally these were settings where the few minutes required for the lamp to run up were also unlikely to present a challenge.
The high system cost, run-up time of several minutes, and requirement of waiting up to 15 minutes in some cases to restart a hot lamp that has had the power cut off all conspired to ensure that despite numerous factors in its favour that metal halide technology either quartz or ceramic never really made any inroads into the domestic market.
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp - General overview
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp - Detail of lamp cap
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp - Close-up of arc tube
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp Packaging
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp - Showing size of lamp
Osram Powerstar HCI-T 70W/WDL Ceramic Metal Halide Lamp - Detail of text printed on lamp base
This lamp added to the virtual display shelf on 1st July 2008.
Acknowledgements: Many thanks to the website reader who donated this lamp to the collection.
This page last updated:
18th June 2023: Updated page text (which was previously largely missing!), made some changes to the page format to improve readability on mobile devices and some background code changes to improve search engine behaviour.