Difference between revisions of "Philips ML"

*Soft glass (100, 160 and 250W) or Hard glass (250 and 500W)

The only slight drawbacks are the lamp's sensitivity to positioning and operating voltage, along with slightly lower than average service life, especially compared with modern lighting technology. The lamp's low efficiency is caused by the compromise of its internal construction. The warm light generated by the internal filament also comes with massive heat radiation, which is similar to typical tungsten lamps that were previously popular.  

The pleasant light is suited both as general lighting in homes as well as gardens or workshops. A good selection of lamps can be used if power consumption is not critical and a specific scene or effect is desirable. Unfortunately, especially in small spaces, the lamp can contribute to heating, which may be advantageous as well as undesirable, depending on application. Special care should be taken when cleaning the lamp as vibrations, dirt accumulation and improper handling can easily crack the bulb, especially on soft glass lamps. Any dirt present on the lamp may be trapped longer due to melting and subsequent adhesion to glass. This means that lamp cleaning has to be as thorough and careful as on old tungsten lamps. While the lamp has a very high output when started and slowly reduces on warm-up, with a corresponding change in light colour, it is not unpleasant. At the beginning most light is output by the internal incandescent fillament rather than the mercury discharge. Lamp restart in case of failure occurs in less than 2 minutes and is less unpleasant than on other high pressure discharge lamps.

This type of mercury vapour lamps were popular mostly before the oil crisis that occured in the 1970s. Many years have passed since use of this lamp was basically non existant, meaning that stocks are not very large. Although the lamp could directly replace even less efficient tungsten or incandescent lamps, this market very rapidly diminished as soon as compact flourescent lamps with screw bases were made available. These had a much longer life, had no restriction on mounting, were highly energy efficient and had even better colour reproduction. There were few fixtures specifically designed for Philips ML lamps. They could operate on typical high pressure mercury vapour fixture but this was uncommon. There was a market for street-lighting in France, many decades ago, as the lamp offered a pleasant light and energy was quite cheap. Due to the lamp operating restrictions as well as simple use, free standing or hanging mounting were quite common, even if lighting efficiency was diminished.

Philips has been releasing lamps for many decades. Lamps produced in the 70s and early 80s are probably not commonly found today. In the 90s and early 2000 Philips was manufacturing lamps in Holland and other countries, while in the last years they were doing the same thing in China. Quality was severely affected as, realistically speaking, there were some occasional lamp defects even in their Holland produced lamps due to average manufacturing quality. It should be noted that mercury vapour lamps were mass manufactured and considered low-cost products, meaning that quality was not paramount.