Lamp Terms Explained

Tanning lamp lingo can be a lot like text-messaging lingo—a bunch of letters and numbers mixed together that somehow can be interpreted to mean something. While I’m not able to really explain the texting thing, I can offer some insight into what those letters and numbers on tanning lamps mean.

No, Not Mr. T

Most fluorescent tanning lamps have certain descriptions printed on the lamp, such as T12. In the lighting industry, a “T” describes the shape of the tubular glass used to make fluorescent lamps. (Yes, tubular—a term most of us haven’t used in more than 25 years.) In the context of contemporary lamp technology, the number after the T describes the maximum outside diameter of the lamp in units. Each of these units equals an eighth of an inch—so, 12 is equal to 12 eighths of an inch. Therefore, T12 refers to a tubular glass lamp with a 1 1/2 inch diameter.

Since fluorescent lamp wattage may be affected by the length and diameter of the glass, a smaller diameter lamp can mean lower operating wattage. For instance, T8 lamps (or 1-inch diameter tubular lamps) are often used for facial tanning applications. Likewise, another popular facial lamp is the T5. (Side note: The tanning industry often refers to T5 lamps as spaghetti lamps—although T5 lamps are not recommended as a source of food, they do appear to have dimensional proportions similar to a strand of pasta.)

When it comes to general lighting fixtures, such as those used in office buildings, energy efficiency is very important. As a result, there has been a trend towards using smaller diameter fluorescent lamps in general lighting for lower wattage. However, with tanning lamps, uniform ultraviolet (UV) light output is more important than energy efficiency, which is why tanning equipment tends to use T12 lamps.

What the ‘F’?

The lighting industry also uses the letter ‘F’ to describe lamps as fluorescent. This is often followed by a length designation. For instance, F71 is a term used to describe a lamp of a nominal length. Ignoring specialty leg tanner and shoulder-length T12 lamps, common T12 lamp lengths include F59, F72, F73, F74, F75 and F79 variations. Now, to really make things confusing, the actual measured length of the lamp is rarely the same as the nominal length used in the lamp description. To add even more to the puzzle, the glass component used to make the lamps are also referred to by number—the glass component for an F75 lamp is 77 glass. So, depending on the lamp manufacturer, F75 lamps can be described as F77, 1.9-meter or ‘long’ lamps.

‘R’ We There Yet?

The letter ‘R’ is used to describe lamps with a reflector coating. For example, FR71 refers to a fluorescent reflector 71-inch nominal length lamp. Reflector coatings concentrate UV output from the lamp in one direction only (inward, or towards the tanner in the unit). This makes built-in reflector shields unnecessary in the equipment.

HO or VHO?

Relax. This has nothing to do with the infamous comments that got Don Imus in trouble. Since fluorescent lamps may be run on a wide range of ballast wattages, certain lamp classifications are described as HO (high output) or VHO (very high output). HO tanning lamps are typically run on 100-watt, 105-watt or 120-watt ballasts. VHO tanning lamps use 140-watt, 160-watt, 165-watt, 180-watt, 200-watt, 240-watt and now even 250-watt ballasts depending on the length of the lamp and the electrode type. Since HO lamps can be operated on a variety of HO ballasts, and VHO lamps on VHO ballasts, some lamp manufacturers have begun to show a range of applicable wattages on the same lamp. For instance the marking on the lamp may read F73 HO 100 watt – 120 watt.

Will ‘BP’ Help Me Fill Up My Tank?

When printed on a tanning lamp, BP refers to bipin—the pair of brass electrical-contact pins protruding from each end of the lamp. BP lamps usually are inserted into the lamp holder and require a quarter-twist to seat the pins properly on each contact point. To that end, filling up your fuel tank with tiny brass pins probably won’t get you very far.

123’s and RDC’s

RDC stands for recessed double contact and refers to the black plastic cap and contact points at each end of the lamp. RDC lamps require a paired system of lampholders using one fixed-position lamp holder and one spring-loaded moveable plunger-type in the tanning equipment. RDC lamp holders have superior electrical contact due to the constant spring pressure on the contact points. RDC is the ideal contact point for today’s very high output tanning applications, however, bipins are still the most popular type used in VHO tanning equipment. In addition to electrical contact with the bipin or RDC lampholder, high output bipin or RDC lamps often have very different electrical characteristics.

Other Confusing Descriptions

Information on high output lamps may include the words preheat or rapid start. This lamp description actually makes an important difference in lamp performance, even though it is frequently ignored in regard to indoor tanning applications. For example, 71-inch bipin preheat and 72-inch RDC rapid-start fluorescent lamps have slightly different glass length. In this case, since the length difference is small, RDC adapters are placed over the brass pins of 71-inch preheat lamps for use in true 72-inch RDC rapid-start applications. Although the spring travel on RDC lamp holders compensates for the length difference between 71- and 72-inch lamps, it will not compensate for the electrical difference and starting characteristics between preheat and rapid-start lamps. For optimal tanning lamp life and starting characteristics, it is recommended to use a genuine rapid start 72-inch lamp for equipment requiring 72-inch rapid-start lamps.

Reading Between the Lines (and Letters and Numbers)

The question of whether to believe everything you read on a lamp is a good one, particularly in regard to the term “everything.” As mentioned earlier, wattage is more often used to give the perception that only a 105-watt lamp can be used in a bed—when, in fact, a high-output 100-watt lamp of similar glass length (assuming UV compatibility) can be used in a 105-watt application or even a 120-watt application. In other words, the HO lamp operates at the wattage that the HO ballast tells it to operate at.

Even the UV strength index printed on the end of the lamp can be either a meaningful or meaningless source of information. Since the actual UV output from the lamp depends on factors including the phosphor blend coated in the lamp, the use of reflector, glass length, electrode type and the ballast powering the lamp, 5.0 does not necessarily mean 5.0. Ultimately, lamps are compared on a case-by-case basis.

Some day, fluorescent lamp manufacturers will be able to better control inventory by making tanning lamps the same way that sausage is made: Cut it to length and cap it! And, at that time, there will only be one question: How would you like your tan—mild, spicy, sweet or hot?

Andrew Anello has been the national sales and market manager for Voltarc Technologies since 2006.

Editor’s Note: After this article was published in Looking Fit magazine, Voltarc Technologies sold its assets to LightSources Inc. For more information, click here.

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