How Much Is Enough?

How Much Is Enough?
Measuring Output Is Crucial For Tanning Success

by Judie Gaillard

Whether you are a seasoned tanning salon owner or the new kid on the block, understanding lamps and how they work is crucial to continued success. In addition to understanding which lamps are compatible with your tanning equipment, salon operators must have a firm understanding of tanning lamp care and output so they can determine when it is time to relamp equipment, as well as knowledge of maintenance factors that can affect a lamp's performance.

The Numbers Game

Every salon operator knows that the tanning lamp is probably the single most important variable in the tanning equation. In fact, more and more salon owners tell us that their customers are becoming more educated about lamps and asking questions about strengths and output.

Although tanning lamps may seem simple to order and replace, they are complex components that figure heavily into the overall tanning process. Each lamp manufacturer has its own definition of useful life for its product, and each tanning salon has its own set of operating conditions. Although both these points are not very helpful in answering the question of when you should replace your lamps, there are some guidelines that can help determine the right point in time.

When examining the output performance of a lamp, as a rule, about 20 percent to 25 percent of the electrical input will be emitted as ultraviolet radiation. However, this only is true for new lamps that are in optimal operating conditions--meaning that the electrical conditions such as supplied voltage, lamp current and wattage meet the specifications of the lamp manufacturer.

Ballasts and starters (if used) also play an important role. The two major factors responsible for the actual performance of a tanning unit are the aging of the lamps over time and equipment characteristics of the tanning unit.

Any radiation source loses a certain degree of power the longer it is in operation. For example, the reduction in power hardly is noticed in the general lighting of private households. In general, incandescent or fluorescent lamps are not replaced until they stop functioning.

Unfortunately, this is not as simple with the UV lamps used for indoor tanning. Tanning units are expected to meet certain requirements with respect to their tanning effectiveness over a given period of time. With increased use, they are no longer able to meet such expectations because of a marked performance decline, even though they are still in full working order from an electrical point of view. With tanning lamps, the recommended "useful life" is considerably shorter than the electrical life.

Normally, manufacturers give recommendations on the "useful life" of their lamps, but these recommendations only can be used as a guide because there is no clear and official definition of the term "useful life." Each manufacturer can make its own definition. Additionally, different operating conditions, as well as equipment-related factors, have in certain cases a considerable effect on the actual useful life of a tanning lamp.

To Replace Or Not To Replace

General consensus indicates that the best and most reliable means of determining when lamps should be replaced is through the correct use of a UV meter. The basic rule of thumb is when the output level has dropped to 70 percent to 75 percent of what it was when the lamps were new, the lamps should be replaced.

Generally, lamps show the highest decline in their output performance during the first 100 hours of operation. For this reason, some lamp manufacturers define their lamp's nominal output performance after 100 hours of operation.

The drop in power between zero and 100 hours can amount to about 10 percent to 20 percent, depending on the properties of the phosphor used inside the lamp. Most of the published maintenance curves were obtained with "free burning" lamps under optimal operating conditions. Therefore, the actual decline in the output of lamps in tanning beds often differs significantly when taken from the salon environment.

There are two different classes of phosphor available for tanning lamps. One type is used in standard tanning lamps and shows a stronger decline in performance, recommending replacement after approximately 300 hours to 500 hours of operation. Another type of phosphor is considerably more expensive and largely used in the professional market of tanning lamps. The gradual decline in performance of these lamps extends their useful life up to 800 to 1,000 hours.

Measuring UVA irradiance is often part of a daily routine for tanning salon operators. For reasons of practicality and cost, the UVA measuring instrument preferred for this purpose is generally an inexpensive pocket-sized type. For financial reasons and customer satisfaction, there should be the best possible assurance that the salon owner can depend on the readout from his or her UV meter.

A UV meter can be a great tool when used properly; however, all too often salon owners are under the misconception that it is an exact measurement for output. If salon owners choose to rely on the UV meter, they should be sure to follow the same format for measuring output which is outlined below.

• Take an initial reading upon the installation of new lamps.
• Make sure the measuring conditions always are kept the same. Measure at the same location of your tanning unit, at the same distance and observe the same electrical conditions for each single measurement.
• Make sure that the acrylics and reflectors are clean. It is imperative that acrylics are changed according to the manufacturer's specifications.
• Wait for your measurement until your tanning unit is in a state of "thermal equilibrium," which takes about 20 minutes to 30 minutes after turning it on.

If these steps are followed, measurement readings for comparative purposes will be obtained. Pocket-sized UVA meters are used to measure UVA values. Although these meters only register UVA levels, it can be assumed that the UVB values will diminish by approximately the same relative amount.

Factors That Affect Output

The total operating time of the lamps is probably the most important factor determining output performance. However, some additional factors stem from the brand of tanning unit used and how well it is functioning.

Equipment-related factors such as dirty or dusty reflectors will reduce power. These issues can be avoided by regularly cleaning your equipment. Other factors include the permeability of the acrylic cover and the cooling system.

Acrylics
Acrylic care is probably the most overlooked element of tanning bed maintenance. It must be noted that it is essential to optimize lamp performance through the use of acrylics that allow for proper transmission of UV energy.

Make sure to check that the reduction of irradiance is not due to insufficient permeability or penetration of the acrylic sheet. Simply use your UVA meter and compare the readings made with and without the acrylic sheet. If UVA readings obtained with the acrylic sheet on the tanning unit are more than 20 percent lower compared to those without the sheet, you probably have an aging acrylic sheet which acts as a filter.

Additionally, yellowing of the cut edges on acrylics indicates it is time to replace the acrylic sheet. It is important that the acrylics be changed with the manufacturer's specifications.

Cooling Systems
As is generally known, a lamp can provide maximum power only if it is operated within an optimum temperature range that is approximately 108 degrees Fahrenheit. If the temperature is too low or too high, it will lead to a drop in output. To check whether the cooling system of your unit conforms to the optimal operating conditions of the lamps, the following procedure can be recommended.

During the warm-up phase of up to approximately 30 minutes after switching on your unit, constantly record the UVA irradiance by use of a UVA meter. The best readings will be obtained in the center of the tanning area. If the reading becomes steady at maximum UVA values, it can be assumed that the cooling of the unit is proportioned correctly.

If, on the other hand, the measured values pass through a maximum before settling at a lower reading, the flow of cooling air is probably too weak. If there is a constant rise in the readings throughout the entire warm-up phase, but without a noticeable maximum being obtained, this should be interpreted as a sign that the unit may be over-cooled. Such problems can be adjusted if the unit allows you to change the cooling airflow. If not, contact the manufacturer of the unit.

Lampholders
Salon operators also should make sure their lampholders are in proper working condition since they support fluorescent lamps and provide electrical connection. There are numerous types of fluorescent lampholders available for the different types of lamp bases.

The most frequently used connector for preheat and rapid start bi-pin lamps is the twist-turn type. Spring pressure push-pull lampholders also are used for bi-pin base lamps. For single lamp ballasts and dimming ballasts, special circuit-interrupting bi-pin lampholders are available. In the case of some single pin lamps, support comes in the form of a high-voltage lampholder with a low-voltage circuit-interrupting feature. This type of connector prevents voltage from being applied to the pins of the lamp until it is secured firmly in both lampholders, reducing the possibility of shock when installing the lamps.

Ballasts & Starters
Ballasts and starters also contribute to lamp performance. Ballasts regulate the flow of electricity into the lamp and they are rated according to the wattage of the lamp for which they are designed. In other words, a 100-watt lamp requires a 100-watt ballast.

Traditionally, ballasts are either electronic or magnetic. The electronic ballasts have the advantage of being lighter than their magnetic counterparts. Magnetic ballasts, while heavier, are more resistant to heat and have fewer parts to fail.

Because of their weight, the placement of ballasts in the top portion of a bed is sometimes used for balance, making the top easier to open and close. If a ballast needs to be replaced, the new one should be attached in the same place as the old, to avoid altering the balance of the canopy.

Separate starters most often are found in beds of European origin. Starters are the spark plugs of tanning beds. When current is applied to the lamp circuit, the starter sends a high-voltage pulse through the electrodes, warming up the lamp and initiating the arc between the electrodes. If starter output is inconsistent or incorrect, you may notice blackening of the lamp ends.