What the letters after the wattage mean, and why two lamps of the same wattage are not interchangeable.
The only reliable identification is the part number etched or printed on the lamp base or on the label wrapped around the anode end. Boxes get reused. Photograph the label before you throw anything away, and send that photo when you ask for a quote.
The part number tells you four things: wattage, lamp family, base and cable configuration, and sometimes the life version. The lamphouse decides which of those combinations fit, so a 3 kW lamp of the wrong family will not mount, or will mount and burn in the wrong position.
An OSRAM code reads like XBO 4000 W/HS XL OFR. XBO is the family (xenon short-arc). 4000 W is the nominal wattage. The letters after the slash describe the version: H = horizontal burn, HS = horizontal with a flexible cable on the anode, HSC = HS with a different cable termination, HTP = horizontal with terminal posts, CA = a cathode-adapter version for particular consoles.
Digital-cinema versions carry projector-specific codes: DHP (Barco), HPN (NEC), DTP and DTS (Christie), HPS (Sony). XL means 'Xtreme Life', a longer-warranty version. OFR means ozone-free — the quartz blocks the short UV that would otherwise generate ozone in the booth. Almost all cinema lamps today are OFR.
UXL is USHIO's film-era xenon short-arc family: UXL-30SC is a 3 kW lamp with a cable (SC). The two digits after the dash are the wattage in hundreds of watts (30 = 3000 W, 40 = 4000 W, 70 = 7000 W).
DXL is the digital-cinema family. The letters after the wattage tell you the projector: BA/BAF = Barco, SN = NEC, SRX = Sony. A suffix after a slash gives the life version: /L = Long Life, /LU = LUMINITY (extreme life). So DXL-40BAF/L is a 4.2 kW long-life Barco lamp, and DXL-45SN/L is a 4.5 kW long-life NEC lamp. Some NEC projectors can also run UXL film lamps with an adapter.
Christie's own-branded lamps are CDXL followed by the wattage in hundreds: CDXL-30 (3 kW), CDXL-45, CDXL-60. Suffixes such as SD, SP, SUP and UP denote successive brightness or life generations for the same wattage. Older PXL codes are the pre-CDXL equivalent.
Two lamps with the same wattage can differ in overall length, light-centre length, base thread, cable length and burn position. The suffix encodes those differences. When you request a replacement, quote the full part number including everything after the slash, and tell us the projector or lamphouse model so we can confirm the mechanical fit before quoting.
Send the part number or a photo of the label and your equipment model. We confirm fit and quote within 24 hours.