9
4.
Product and method terminology
Term
Explanation
UV system
The UV system is the complete system, consisting of the UV
reactor, the switch cabinet and the ancillary equipment.
UV reactor
Core component in a UV system, consisting of a reactor housing
plus reactor chamber, UV emitters, immersion tubes and UV
sensors with various screw fittings.
Switch cabinet
Core component in a UV system, consisting of a switch cabinet
housing with ballast units to supply the UV emitters with power,
an analysis unit for the UV sensor and electrical components to
operate the UV system.
UV emitter
Component in the UV reactor that generates UV light. The UV
emitter is integrated into the immersion tube.
Immersion tube
Component in the UV reactor that is immersed in water. The
immersion tube contains the UV emitters.
UV sensor
Component for the continuous measurement of the UV-C
irradiation strength in the irradiation chamber.
Deposit
Deposition of waterborne substances in the irradiation chamber,
and esp. on measurement window and immersion tube.
Shutoff valve
Used to shut off the flow of water in inlet/outlet, manually or
automatically.
Irradiation chamber
Part of the UV reactor where water flows through.
Disinfection
Killing off/inactivation of microorganisms, including pathogenic
microbes.
Minimum irradiation
strength
A value for measuring irradiation strength, specific to the type of
UV disinfection device and application, measured with a UV
sensor. The minimum irradiation strength and maximum flow
rate must be maintained during operation of UV disinfection
equipment to ensure the required level of disinfection is
achieved.
UV dose (fluence)
Specified in J/m
2
or mJ/cm
2
. The amount of UV light that must
be applied in order to achieve a specified disinfection result. A
metric for disinfection capability.
UV transmission
Relationship of emitted irradiation to incident irradiation. UV
transmission is measured in % on a layer thickness or specified
as a spectral absorption coefficient of the wavelength 254 nm
(SAC-254).
The SAC measurement encompasses both absorbent water
constituents (colour) as well as the scattering of light by
suspended particles (turbidity).
W/m²
Unit of measure for UV irradiation strength.
UV-C
Shortwave (200–280 nm) UV light, a part of the electromagnetic
spectrum.
UV light
Light invisible to the human eye, generated by the sun or a UV
emitter.
Boot phase
Time from when the UV system is switched on to “System ready
for use”.
Minimum flow rate
Required to avoid overheating.
Emitter lifespan
Expected usable lifespan followed by degradation of UVC 254 nm
output
HG lamps
UV-C mercury lamp
HGA lamps
UV-C doped mercury amalgam lamp
