Today a reader Grant Margaryan came to my Lamptest laboratory and brought three metal halide lamps with a luminous flux of 7800, 13000 and 17500 lumens. This is about 20-45 ordinary light bulbs in my home chandelier.
Metal halide lamps (here Wikipedia article about them) have a very high efficiency (up to 111 lm / W) and give white light with high color rendering indices. Such lamps are often used in art galleries and expensive clothing stores.
The 70-150 W lamps themselves cost 1200-1300 rubles, they also need a driver, which costs about 2000 rubles.
The light bulb looks like this (do not pay attention to the contacts, this is "tricky to invent" in the absence of a cartridge for the G12 base).
When turned on, the driver supplies about 5000 volts to the lamp, when it flares up, the voltage drops to 250 V. The lamp lights up for about a minute - while it all looks as if the lamp is faulty - it flashes, goes out, changes colors (the light is reddish, then bluish, then greenish), but after a minute everything stabilizes and the lamp begins to shine even white light.
After the lamp turns off, the sphere inside glows orange for about a minute, so much it gets hot during operation.
The lamp can only be switched on again after it has cooled down.
We measured the light parameters of the lamps using an Uprtek MK350D spectrometer.
Lamp Philips MASTERColour CDM-T Elite 70W / 930 G12 1CT / 12 (70 W, 7800 lm).
Lamp Philips MASTERColour CDM-T 150W / 830 G12 1CT (150W, 13000 lm).
OSRAM HCI-T 150W / 930 WDL POWERBALL G12 lamp (150 W, 17500 lm).
All lamps have a CRI (Ra) color rendering index of about 90, while lamps of the Elite series are higher than R9 and a rise in the spectrum in the red region is clearly visible.
The driver consumes about 10 W, therefore the lamps with the driver consume 80.6, 158.3, 160 W, respectively.
My little half-meter integrating sphere is not designed to measure such bright light sources, we got the results of 7075 lm, 12320 lm and 15390 lm, but I fully admit that these readings are a little underestimated.
Very interesting light bulbs.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, v LJ, Zen, Mirtesen, Telegram.
My projects:
Lamptest.ru. I test LED lamps and help figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in Telegram @ ammo1 and by mail [email protected].