VWR Collection PCR Workstation
22
MEASURING UV TUBE INTENSITY
As UV tubes age, intensity and germicidal destruction rate decreases. We recommend you change
the UV tubes after 1000 – 1500 hours of operation (please refer to "Checking and resetting the hours
of durty", page 19). Otherwise it is important to monitor the efficiency of the tubes to ensure
germicidal requirements are met. The germicidal destruction rate is a function of the UV intensity at
wavelength 254 nm and exposure time. The lower the tube intensity, the longer the lamps must be on
to accomplish the same objective.
A UV Intensity Meter with 254 nm sensor will allow the user to measure the 254 nm emissions from
the tubes. When it is time to measure the UV intensity inside the PCR Workstation, the sensors can
be placed on the floor of the PCR Workstation. Close the front panel and turn on the UV tubes.
Please refer to the UV radiometer manual on how to perform the measurement. It is recommended
that the user records an initial value upon receipt and assembly of the PCR Workstation.
To measure the UV intensity from the UV Air Recirculator tube, open the cover lid on the back of the
PCR Workstation and perform the measurement as described in the UV radiometer manual. Wear
protective eyewear and shielding when operating the UV Air Recirculator with the ventilation cover
open. Replace the cover and screws after the measurement is completed.
