How does the wattage of the tube/bulb compare to UV output?
The design of the lamp fixture can make large variations in the amount of UV that a lamp fixture emits even for fixtures using the same tube/bulb. The size of the filter glass, the shape of the reflector, the material the reflector is made from, the kind of filter glass, hours of use of the lamp, and the internal temperature of the lamp fixture all have major effects on the final output of the lamp fixture. There has been some independent testing of various brands of UV lamps. The information gets complicated and I will devote another section to those details. For this information, I want to stick with easily referenced values, so I will use the values that are published by Philips. According to the Philips catalog at 100 hours of use: a 4 watt tube/bulb emits a total of 0.9 watts of UV C (SW) a 9 watt tube/bulb emits 2.4 watts (overdriving them with a 13 watt ballast, causes them to emit about 3.2 watts) a 15 watt tube/bulb emits a total of 4.7 watts of UV C a 18 watt tube/bulb emits
The design of the lamp fixture can make large variations in the amount of UV that a lamp fixture emits even for fixtures using the same tube/bulb. The size of the filter glass, the shape of the reflector, the material the reflector is made from, the kind of filter glass, hours of use of the lamp, and the internal temperature of the lamp fixture all have major effects on the final output of the lamp fixture. There has been some independent testing of various brands of UV lamps. The information gets complicated and I will devote another section to those details. For this information, I want to stick with easily referenced values, so I will use the values that are published by Philips.
