OSRAM POWERTRONIC PT-FIT I ECG for HID lamps, with cable clamp - Manual (Page 5)

1. The system HID lamp and ECG
THE SYSTEM HID LAMP AND ECG
1.1. High-pressure discharge lamps
Metal halide lamps and high-pressure sodium vapor lamps
both belong to a group referred to as high-pressure dis-
charge lamps. In contrast to what happens in low-pressure
discharge, the discharge tube in such lamps operates at
high temperatures and pressures. The light in discharge
lamps is generated in a gas discharge that takes place in
the arc tube between two electrodes after ignition. In the
case of high-intensity discharge lamps, the arc tube is ge-
nerally housed in an evacuated outer bulb, which thermally
insulates the hot arc from the environment in a similar way
to the principle used in a thermos fl ask. However, there are
also discharge lamps that do not have any outer bulb, and
also ones with an outer bulb fi lled with gas.
During gas discharge, the metal halide additives and mer-
cury or calcium amalgam are excited by the fl ow of current
and emit excitation energy in the form of the radiation
characteristic of each of the elements it contains. The
mixture of different radiation components produces the
desired color temperature and color rendering properties.
5
Figure 1: Structure of a quartz burner
The illustration above shows the structure of a metal
ha lide lamp as an example of a double-ended lamp with
a quartz burner.
Metal halide lamps and high-pressure sodium vapor lamps
are also referred to as HID lamps, which stands for High
Intensity Discharge lamps.
Metal halide lamps can also be referred to as HIT lamps
(using the "LBS" lamp designation system):
H: High-pressure
I: Iodide
T: Tubular
They are also often called MH (Metal Halide) lamps.
Metal halide lamps are principally characterized by
the following properties:
• Good luminous effi cacy
• Long service life
• Very good color quality
• Good to very good color rendering
• Point light source, with benefi ts in light control
and lighting brilliance
More detailed information on metal halide lamps can be
found in the following application guide: "Metal halide
lamps – hints on application and use"
Sodium vapor lamps are also referred to as HS
("High-pressure Sodium") lamps. They are principally
charac ter ized by the following properties:
• Optimal energy effi ciency
• Long service life
• Good reliability
• Very high luminous effi cacy
• Very good lumen maintenance
• Good dimming behavior
More information on sodium vapor lamps can be found in
the following application guide: "High Intensity Discharge
lamps"
1.2. The POWERTRONIC ® ECG
Electronic control gear (ECGs) for the operation of metal
halide lamps with ceramic (HCI) or quartz burners (HQI)
or sodium vapor lamps (NAV) are all referred to using the
term POWERTRONIC
® at OSRAM.
POWERTRONIC ® ECGs replace all the conventional
system components of a luminaire (choke, ignition unit
and correction capacitor), thus making the assembly
substantially simpler. Other benefi ts include the ability to
optimally operate the lamp so as to maximize the lamp
service life and minimize the lumen loss.
Electronic control gear has become the right choice for
operating metal halide lamps with ceramic burners, as its
technical properties are able to make the most of the full
potential of such lamps.
Discharge
arc Heat
Reflector UV Filter Outer bulb
(Quartz)
Arc Tube
(Quartz)
Contact
Plate
Molybdenum
Foil
Molybdenum
Foil Metal
Halides Electrode Mercury Getter
Lead-in
wire Base
OPERATION MODE OF A HIGH-PRESSURE DISCHARGE LAMP