Fluorescent lamps
BIOLUX
FH/FQ
- Brightness control
- Difference between FH and FQ
- Gas in fluorescent lamps
- Reduction of UV percentage
- Three-band lamps
- Type L 40/79K
General infromation on fluorescent lamps
- Application underground car park
- Change in light color with dimming
- Change in light colour with fluroescent dimming
- Connecting starter
- Daylight-white light colours
- Extended life by switching off
- Fluorescent lamp temperatures
- Fluorescent lamps in/for US
- Glowing of fluorescent lamps
- Lamps with low UV radiation
- Lamps with protective tube, splinter protection
- Light colour 19
- Light colour 23
- Light colour 26
- Light colour 36
- Light colour 39
- Light colour 62 YELLOW
- Light colour against algae growth in aquariums
- Light colours for colour matching
- Light colours in the office
- Operation at 60 Hz
- Radiation
- Reduction of UV percentage
- Reduction of thermal loading of fluorescent lamps
- Service life of fluorescent lamps
- Short-term operation
- Switch cycles
- Tandem circuit
- Temperatures on the lamp
- Tube of fluorescent lamps
- UV absorption of a black light lamp
LUMILUX, LUMILUX PLUS, LUMILUX PLUS ECO
- Burning in T 5
- Burning position of T 5 (16 mm) lamps
- Coloured T 5
- L 115W/20 SA
- L 40W/...S, L 65W/...S lamps
- LUMILUX, LUMILUX PLUS, LUMILUX PLUS ECO
- Luminaires with T 5 lamps
- Specifications of L 33W fluorescent lamp
- T 5 (16 mm) fluorescent lamps
- T 5 in exterior lighting
Old types
Well being with BIOLUX
Question
Is the well being increased if one interchanges the lamps in one's work place with a BIOLUX?
Answer
Due to the low efficiency of the BIOLUX we advise against the installation of this lighting in the workspace.
UMINUX SKYWHITE brings a very positive effect on motivation and quality of life - please gather details from the brochure (to be found in the download area).
Brightness control
Question
Are the types L 40W/21DS and L 65W/21DS for brightness control still available or which alternatives exist for these?
Answer
No, lamps of this kind with a 38 mm diameter and provided with an ignition foil originated in the early 1980s and have been replaced by T 8 (26 mm) lamps in conjunction with dimmable ECGs that can be controlled very well in the range from 100 to 1 % luminous flux. The dimmable ECGs are designed as fully electronic, one-piece units to enable easy conversion. Here it is an advantage that normal T 8 (26 mm) lamps can be used instead of the previous expensive special lamps.
Difference between FH and FQ
Question
What is the difference between the types FH and FQ for the T 5 (16 mm) fluorescent lamps?
Answer
FH or HE lamps offer extremely high luminous efficacies up to 104 lm/W. FQ or HO lamps offer very high lumen packets of up to 7000 lm. Linear T 5 (16 mm) fluorescent lamps have four lamp lengths and are 5 cm shorter than the lengths of the T 8 (26 mm) lamps as a basis (55, 85, 115 and 145 cm), i.e. a FH lamp and a FQ lamp have the same length with different wattages (e.g. same length of 115 cm for FH 28W and FQ 54W).
FH (14 to 35 W) lamps are lamps with a very high luminous efficacy with values up to 104 lm/W, FQ lamps (24 to 80 W) are lamps with an increased lamp wattage and higher luminous flux values per lamp for direct and indirect lighting, high rooms and for industrial lighting. FH can be used for offices and good architectural design with a high energy efficiency. FQ lamps are therefore used where a high luminous flux value per lamp unit is required, as the luminous efficacy of the FQ lamps is around 90 lm/W.
The use of the respective design FH or FQ is dependent on the type of system and on the luminaire type.
FQs are particularly well-suited for direct/indirect lighting, high rooms and for industrial lighting. FH can be used for offices and good architectural design with a high energy efficiency.
Gas in fluorescent lamps
Question
Which gas is contained in fluorescent lamps? (Transport - Dangerous Goods)
Answer
Fluorescent lamps are generally filled with the inert gas argon or with mixtures of argon, neon and krypton. In addition, part of the mercury required for radiation generation is in the vaporous state, while the main quantity is liquid under normal conditions. As a result, fluorescent lamps are subject to disposal laws in the commercial sector. In household use this will become law in the EU beginning in March 2006 with the WEEE (Waste of Electrical and Electronic Equipment) Directive.
Reduction of UV percentage
Question
By how much is the UV radiation reduced if a COLOR control L58W/940 UVS is replaced with an L 58W/940?
Answer
The filtering tube stops the UV light to 99%.
Three-band lamps
Question
What is understood by "three-band lamps" and which types do they include?
Answer
"Three-band lamps" are the currently day-to-day standard, and are offered by OSRAM under the brand LUMILUX. Hereby light is effectuated by three phosphors, whose combination causes a white light of great quality.
| 827 | 2700 K INTERNA |
| 830 | 3000 K Warm White |
| 835 | 3500 K White |
| 840 | 4000 K Cool White |
| 865 | 6500 K Cool Daylight |
| 880 | 8000 K SKYWHITE |
Application underground car park
Question
Which fluorescent lamps can be used to illuminate underground car parks in which the lamps are also frequently switched?
Answer
Single-lamp luminaires with a cover (damp-proof luminaires) for 58 W fluorescent lamps equipped with a suitable warm-start ECG are recommended.
The device QTS 1 x 55-58/230-240 from OSRAM is recommended as the ECG. It is especially matched to the properties of the lamp in conjunction with frequent switching. In addition to the selection of the lamp, luminaire and ECG, it should also be ensured that each illuminated cycle is not less than 10 min. (15 min. is better). The reason for this is that following ignition of the lamp, its electrodes require a certain time for the so-called free burning.
The use of a dimmable electronic ballast (1 - 10 V interface) is ideal. Here the lamp is then operated in the so-called "off position" with 1 % luminous flux with short-circuited control terminals; switched on then means open control terminals, and therefore 100% luminous flux. This means the control terminals are used for switching. This operating mode has the advantage that the lamp electrodes are always sufficiently maintained at the emission temperature. The disadvantage is the energy consumption of approximately 13 % even during so-called "off position" due to the continuous preheating of the electrodes.
The solutions described are considerably better than the operating mode with a choke/starter with regard to the service life of the lamps, however short-term operation results in a reduction in the service life of the lamp which, on the other hand, remains within reasonable limits with the described operating mode with an ECG.
Change in light color with dimming
Question
How does the change in the light color with dimming show itself? (T5)
Answer
The change in the light color is hardly noticeable in applications with freely suspended, dimmed lamps.
During an operation in e.g. narrow or closed luminaires, changes in the light color may appear due to significant temperature differences around the lamps (through heat accumulation within the luminaires).
Change in light colour with fluroescent dimming
Question
Does the light colour change when fluorescent lamps are dimmed?
Answer
For a colour matching procedure OSRAM offers the COLOR proof (5400 K) according to Standard D50.
Connecting starter
Question
How is the starter connected to the fluorescent lamp?
Answer
A circuit diagram for this purpose is located at the end of Chapter 4 in the Lighting Program.
Daylight-white light colours
Question
Which light colours of OSRAM fluorescent lamps belong to the daylight lamps?
Answer
According to DIN 5035 and CIE the group of so-called daylight white fluorescent lamps include those lamps with a colour temperature > 5000 K. The line of daylight white lamps include the following models:
| Light colour 765 | approx. 6500 K | BASIC-Lampe |
| Light colour 954 | approx. 5400 K | LUMILUX DE LUX |
| Light colour 865 | approx. 6500 K | LUMILUX |
| Light colour 965 | approx. 6500 K | LUMILUX DE LUX |
| Light colour 880 | approx. 8000 K | LUMILUX SKYWHITE |
The light colour 965 can be viewed as the more or less standardized light colour D65.
Extended life by switching off
Question
When is it worth it to switch off fluorescent lamps?
Answer
The service life of fluorescent lamps is defined by the switching rhythm of 165 minutes ON and 15 minutes OFF specified in the IEC.
A lighting system with fluorescent lamps should therefore not be switched off when the interruption times (OFF times) are less than 10 - 15 minutes.
Fluorescent lamp temperatures
Question
How does an FQ fluorescent lamp behave at temperatures between 80 and 120°C?
Answer
The luminous efficacy drastically decreases, as ECGs (electronic control gear) are generally only approved for use up to ambient temperatures of 50°C. In addition, under these conditions the permissible base edge temperature is exceeded (for all FH and FQ max. 120°C), depending on the luminaire design.
Fluorescent lamps in/for US
Question
Are there comparable fluorescent lamps that can be used both in Europe and the US?
Answer
As a European development (HE, HO), the new system of the T 5 (16 mm) tubular fluorescent lamps is also available in the US, which results in excellent matching.
On the other hand, there is no agreement for the T 12 (38 mm) and T 8 (26 mm) lamps, as due to the different voltage systems (120 V/60 Hz, 277 V/60 Hz) other operating systems with different lamps also exist in the US.
Glowing of fluorescent lamps
Question
Why do fluorescent lamps continue to glow the entire night, although they are switched off?
Answer
Fluorescent lamps do not necessarily act this way. It depends on the luminaire - if following switch-off a potential is present compared to the surrounding area, mercury atoms will be excited to produce UV radiation, which, as is also otherwise the case, is converted in the phosphor to visible light. It is not a storage effect!
Lamps with low UV radiation
Question
Which fluorescent lamp from OSRAM has a very low level of UV radiation?
Answer
The UV radiation of normal fluorescent lamps is so low, as very little UV radiation reaches the outside due to the phosphors selection and absorption properties of the tube glass, and even with higher illuminance values and long operating times no health problems are to be expected, particularly since the distance between lamp(s) and persons and/or materials is usually also large.
However, for some critical materials such as pictures etc. it is an advantage due to a usually relatively long exposure time to use fluorescent lamps with a very low UV percentage. Here COLOR control in light colour 940 (4000 K) is recommended, which is characterized by an excellent colour reproduction (level 1A). Due to the protective tube applied to the lamp, the already very low UV radiation level is further drastically reduced.
The product range of COLOR control incorporates:
- L 18W/940 UVS
- L 36W/940 UVS
- L 58W/940 UVS
- L 58W/954 UVS
The average service life is 10,000 hrs. (limited by changes in the tube material)
Lamps with protective tube, splinter protection
Question
Does OSRAM have fluorescent lamps with a protective tube in its product line that can be used in certain areas of the food processing industry?
Answer
Yes, the so-called SPLIT control (SPS) on which an additional protective tube is applied to the lamp that holds the lamp parts (glass etc.) if the lamp breaks as the result of mechanical influence on the lamp. This prevents parts of the lamp from being able to fall out of the luminaire.
Light colour 19
Question
Fluorescent lamps for colour matching with the designation 19 Daylight 5000 de Luxe are still installed in a system. Which light colour can now be used?
Answer
For a colour matching procedure OSRAM offers the COLOR proof (5400 K) according to Standard D50.
Light colour 23
Question
What does light colour 23 mean ?
Answer
This is the light colour 3500 K in a halophosphate (BASIC) lamp. For historical reasons this light colour is preferred in Great Britain (UK), although even here the trend is headed towards lamps with 4000 K.
Light colour 26
Question
What does light colour 26 mean ?
Answer
This refers to the light colour 3500 K in a triphosphor (LUMILUX) lamp. For historical reasons this light colour is preferred in Great Britain (UK), although even here the trend is headed towards lamps with 4000 K.
Light colour 36
Question
OSRAM also offers fluorescent lamps with the light colour designation 36. Which is the replacement model?
Answer
These are the so-called NATURA lamps, which are now available with improved characteristics under the light colour designation 76. Lamps of this kind are specifically set to illuminate groceries in professional areas.
Light colour 39
Question
What is the replacement model for the previous light colour 39?
Answer
What is the replacement model for the previous light colour 39?
Light colour 62 YELLOW
Question
What recommendations are there for operating the light colour 62 YELLOW?
Answer
The yellow light of this lamp is achieved in conjunction with a yellow tube that not only provides excellent radiation filtering below 500nm, but simultaneously serves a protective function. The average lamp life is 10,000 hrs. The reason for this limitation is the ageing of the tube material (depolymerisation) as a result of the thermal loading and of the UV radiation, both of which directly affects the material.
Light colour against algae growth in aquariums
Question
Which light colour will suppress algae growth in my aquarium?
Answer
Here we recommend light colour 865-6500K.
Not more than 100,000 lux should be present at the water surface!
Light colours for colour matching
Question
Which light colours of fluorescent lamps can be used for colour matching purposes?
Answer
For colour matching OSRAM offers the COLOR proof with a Ra of 98 and light colour 5300 K (Norm D50).
Light colours in the office
Question
Can fluorescent lamps with the light colour BIOLUX (6500K) also be used in office lighting?
Answer
Due to the low efficiency of this lamp compared to LUMILUX and LUMILUX DE LUXE lamps we advise against this condition. In any case a much lower luminous flux should be considered when resupplying and an inspection of the minimum illumination is necessary.
Operation at 60 Hz
Question
Can fluorescent lamps also be operated at 60 Hz?
Answer
Yes, in conjunction with corresponding conventional control gear (CCG, VCG) or with electronic control gear (ECG) designed for 60 Hz.
Radiation
Question
Do fluorescent lamps give off radiation between 800 and 900 nm?
Answer
Normal temperatures between 20 and 40°C:
T8 fluorescent lamps switch over to stable Hg discharge very quickly here, i.e. an Hg line first becomes noticeable at 1040 nm.
The smaller the tube diameter, e.g. T4 for DULUX EL, the greater argon is excited and it takes a finite time after ignition until discharging only takes place via Hg. This means a small percentage of radiation between 800 and 900 nm results here.
Temperatures < 20°C, especially temperatures below freezing:
Here as well, there is a dependence on the tube diameter, i.e. following ignition argon is excited for a long time or forever and unfortunately radiates especially in the wavelength range of 800 - 900 nm.
The absolute IR radiation percentage is naturally dependent on the lamp type, however at low temperatures a more or less high argon radiation percentage always remains following ignition in the range of 800 - 900 nm, which does remain for different lengths of time.
Reduction of UV percentage
Question
By how much is the UV percentage of an L 58 / 22- 940 reduced when an L 58 / 22 - 940 UVS is used?
Answer
The filtering tube stops the UV light to 99%.
Reduction of thermal loading of fluorescent lamps
Question
How can the thermal loading of fluorescent lamps be reduced?
Answer
With corresponding design of the luminaires that enables sufficient convection in the luminaire.
Service life of fluorescent lamps
Question
How long is the service life of fluorescent lamps?
Answer
The specification of the average service life (SL) indicates that 50 % of the lamps used often may have failed up to this value, whereby the test must be conducted under standard conditions. For fluorescent lamps, this primarily means operation at nominal voltage and at an ambient temperature of 25° C, as well as switching at most 8 times per 24 hrs. (switching rhythm 165 min. on, 15 min. off).
In addition, the term economic life (EL) is often used, and strictly speaking this specification also applies only to a system containing several lamps. The economic life is reached when the luminous flux drops below the limit of 80 % in the system. The economic life is the result of the two factors lamp failures and light deprecation. The light deprecation for fluorescent lamps is partially highly dependent on the phosphor and its ageing behaviour or from the coating technology. Major differences result for the BASIC light colours and the lamps coated with LUMILUX phosphor (three-band phosphors with single-layer technology).
Of course, the operating mode also has a major effect on the economic life of the lamp. Higher values are achieved with the ECG operating mode (warm-start ECG) compared to the CCG/VCG operating mode. The following values are specified for the main lamp types:
| Lamp | Control gear | Average durability (50%- mortality) | Beneficial durability (80% luminous flux) |
| BASIC T8 (26mm) BASIC light colours (10 - 58W) |
CCG | 13.000 | 5.000 |
| LUMILUX T8 (26mm) (10 - 58W) |
ECG | 20.000 | 18.000 |
| BASIC T12 (38mm) (20 - 65W) |
CCG | 10.500 | 4.500 |
| LUMILUX T5 HE (16mm) FH (14- 35W) LUMILUX T5 HO (16mm) FQ (24 - 80W) |
ECG | 24.000 | 18.000 |
| LUMILUX T5 (16mm) (4 - 13W) |
ECG | 7.000 | 5.000 |
| BASIC T5 (16mm) (4 - 13W) |
CCG | 5.000 | 2.500 |
| LUMILUX T5 FC (16mm) (22 - 55W) |
ECG | 16.000 | 9.000 |
| LUMILUX T2 (7mm) (6 - 13W) |
ECG | 8.000 | 6.000 |
Remarks : |
LUMILUX (three-band phosphors with single-layer technology) BASIC (halophosphate lamps) |
||
Short-term operation
Question
Can fluorescent lamps also be used for short-term operation, e.g. in display lighting with short sequences in individual segments or for clocking?
Answer
Fluorescent lamps and compact fluorescent lamps are designed for longer operating times per switching; shorter burning times automatically result in a shorter lamp life. This effect can be reduced to a certain degree when corresponding high-grade electronic ballasts are selected. A general recommendation cannot be given, as each case consists of different specifications or presettings for use (e.g. different on and off times).
Switch cycles
Question
How are the switch cycles with fluorescent lights / discharge lamps defined?
Answer
The switch cycles of discharge lamps are:
| Type of lamp | Switch cycle | Remarks |
| Fluorescent lamps | 3 h (2 hrs. 45 min ON, 15 min OFF). | IEC |
| 12 h (11:30 ON, 00:30 OFF). | In preparation |
Lamps involved in industrial applications are increasingly based on 12 h switch cycles (11 h on, 11 h off); Here OSRAM's preparations on the according economic lifetime for the lamp palette are in process.
Tandem circuit
Question
Can fluorescent lamps also be used for short-term operation, e.g. in display lighting with short sequences in individual segments or for clocking?
Answer
Fluorescent lamps and compact fluorescent lamps are designed for longer operating times per switching; shorter burning times automatically result in a shorter lamp life. This effect can be reduced to a certain degree when corresponding high-grade electronic ballasts are selected. A general recommendation cannot be given, as each case consists of different specifications or presettings for use (e.g. different on and off times).
Temperatures on the lamp
Question
What temperatures can occur on the new-generation T 8 (26 mm) and T 5 (16 mm) fluorescent lamps?
Answer
The following values are the limits (maximum values) of the cap edge temperature that must be complied with by the luminaire manufacturer:
| T 8 - fluorescent lamps up to 36 W | 120° C | |
| T 8 - fluorescent lamps up to 58 W | 140° C | |
| T 5 - fluorescent lamps | 120° C |
These are safety-related values of the cap edge temperature.
To provide additional information several temperatures are named for fluorescent lamps in freely burning operation :
| Lamp | Lamp centre °C | Electrode area °C |
| T8 / L36W | 45...55 | 100...120 |
| T8 / L58W | 50...65 | 110...130 |
| T5 / FH 28W | 40...60 | 160 (200...250 *) |
| T5 / FQ 54W | 50...70 | 160 (200...250 *) |
* Temperatures that occur when lamps are operated on incorrect ECGs, e.g. FH 28W on the ECG for FQ 54W.
As a result, no foils may be applied to T 5 lamps (impermissible operating mode).
Tube of fluorescent lamps
Question
Can the tube of fluorescent lamps with special light colours be pulled off?
Answer
This is not recommended, as the lamp can be damaged in the process.
UV absorption of a black light lamp
Question
A black light lamp is to be installed in luminaires. How much UV does the cover absorb?
Answer
The UV absorption is highly material-dependent, so that unfortunately no general statement can be made. Therefore, the luminaire manufacturer should be asked.
Burning in T 5
Question
Are T 5 (16 mm) fluorescent lamps to be burned in?
Answer
According to the Norm we recommend a firing time of 100 hours to ensure the complete stabilization of new lamps under full load.
Burning position of T 5 (16 mm) lamps
Question
Can the new T 5 (16 mm) fluorescent lamps also be used in any desired burning position?
Answer
Yes, FH and FQ lamps can be used in any burning position. Generally the luminaires are mounted on the ceiling or hung from the ceiling so that a horizontal burning position results for the luminaire. In cases in which the lamps or luminaires are arranged vertically or at an angle, the lamps must be fitted so that the end with the type designation (stamp) is located at the bottom (coldest necessary position for optimum luminous flux at the bottom). With FC the circular T 5 and vertical arrangement, the lamp cap is to be located at the bottom.
Coloured T 5
Question
Does OSRAM also have coloured T 5 fluorescent lamps in its product range?
Answer
Yes. Please gather details off the light programme. The operational attributes of the coloured lamps are identical to those of types usually used for illumination purposes in according colours, i.e. operation with ECG and instructions on arrangements should be taken into consideration.
L 115W/20 SA
Question
What are the data of the fluorescent lamps L 115W/20 SA?
Answer
The L 115W/20 SA lamps are equipped with an external conducting strip and are primarily used for lighting in cold storage buildings, since as so-called high-performance lamps they still have an acceptable temperature-to-luminous-flux behaviour for this application.
Today we recommend T5 HO CONSTANT that can offer a high luminous flux even at low temperatures for these applications.
L 40W/...S, L 65W/...S lamps
Question
What are the main characteristic values of the lamps L 40W/?S and L 65W/...S?
Answer
In the original application the lamps L 40W/?S and L 65W/?S were intended for operation on rapid-start (RS) devices, however can also be used for choke/starter operation. The lamps are used in older road lighting systems in luminaires without or with minimal heat insulation, i.e. usually where low ambient temperatures prevail. They are also used in certain mostly older all-plastic luminaires.
LUMILUX, LUMILUX PLUS, LUMILUX PLUS ECO
Question
What differentiates the terms LUMILUX, LUMILUX PLUS, LUMILUX PLUS ECO for OSRAM fluorescent lamps?
Answer
LUMILUX is the OSRAM brand for fluorescent lamps of Ra > 80. At different points in time the various progresses of this lamp technology were differentiated into PLUS or PLUS ECO - these days all terms have been joined again to LUMILUX.
Luminaires with T 5 lamps
Question
What must be observed when using T 5 lamps in multi-lamp luminaires?
Answer
The distance between the lamps must amount to about 32 mm.The lamps are to be inserted in such a way that the sides with the type designation (stamp) are next to eachother.
When operating vertically the stamps must be arranged at the bottom.
Specifications of L 33W fluorescent lamp
Question
What are the specifications of the L 33W fluorescent lamp?
Answer
This lamp is no longer included in our range.
T 5 (16 mm) fluorescent lamps
Question
Why are two values given for the luminous flux of T 5 (16 mm) fluorescent lamps?
Answer
Linear T 5 (16 mm) fluorescent lamps of the types FH and FQ achieve their maximum luminous flux at a lamp ambient temperature of 35° C (-1 / 3 K), i.e. at a temperature that results during operation in virtually all luminaires for fluorescent lamps. Usually this results in a higher luminaire efficiency.
The luminous flux is generally set at 25°C in the Norm IEC 60081, as this (based on the T8) acts as planning criteria and also as basis for photometric readings. Hence the luminous flux is announced at 25°C for planning and measuring purposes.
T 5 in exterior lighting
Question
Can T 5 (16 mm) fluorescent lamps also be used in exterior lighting?
Answer
T5 were originally optimised for the interior zone - with a luminous flux optimum of 35°C inside temperature.
For the exterior area OSRAM offers the T5 HO CONSTANT as special lamp that offers a luminous flux of > 90% optimum even at only 5°C inside temperature. Depending on the construction of the light (to ensure a high inner warmth) a good luminous flux can also be achieved at minus temperatures.
L 33W lamp
Question
The L 33W lamp is an older type of the T 12 (38 mm) fluorescent lamps and can still be frequently found in older systems due to its overall length. What are the main data of this lamp type ?
Answer
| Lamp wattage | 33 W |
| Lamp current | 0,572 A |
| Lamp voltage | 63,5 V |
| Light color | 25 |
| Luminous flux | 1,650 lm |
| Length | 740 mm |
| Diameter | 38 mm |
| Cap | G13 |
| Starter | ST 151 |
Operating mode: Series connection of two lamps on the CCG for L 65W and 2 x ST 151 or individual operation with two CCGs for L 65W and ST 151 connected in parallel.
L 40W/...SA, L 65W/...SA lamps
Question
What are the main characteristic values of the lamps with external conducting strips L 40W/...SA and L 65W/...SA ?
Answer
These lamps with external conducting strips belong to the group of older T 12 (38 mm) fluorescent lamps and are still used in older lighting systems that are usually present in the area of low or sub-zero ambient temperatures (e.g. in cold storage buildings). The lamps with the connected external conducting strip are preferably operated in the so-called RD circuit (resonance double choke), although operation with a choke and starter (ST 111) is also possible.
Old types L 25W, L 42W
Question
Fluorescent lamps with a 38 mm diameter L 25W (970 mm) or L 42W (1,047 mm) can be found in older lighting systems. What are the new types of the same length called?
Answer
With the introduction of the T 8 (26 mm) fluorescent lamps, major types of the T 12 (38 mm) lamps were replaced with T 8 (26 mm), which also applies to the types with so-called special lengths. Here full replaceability is given, as the length, electrical data and accessories are the same.
| O l d | Replacement type |
| L 42W (1047 mm) | L 38W (1,047 mm) |
| L 25W ( 970 mm) | L 23W ( 970 mm) |
Electrical and luminous data of the 23W and 38W lamps are contained in the OSRAM Lighting program.