UV-C Radiometer for disinfection effectiveness and safety of UV-C LEDs and germicidal lamps

The X1-1-UV-3726 radiometer enables the effectiveness of UV germicidal irradiation (UVGI) to be accurately determined for both low pressure mercury (254nm) germicidal lamps and UV-C LEDs. Additionally, the device has sufficient sensitivity to detect if undesired exposure poses a photobiological safety risk to users. UVGI is a sterilization method that uses UV-C light to break down microorganisms such as viruses and bacteria by altering their DNA and RNA, rendering them unable to replicate.

The germicidal effectiveness of UV-C radiation depends on its dose (µJ / cm2) and wavelength. The dose is determined by measuring the irradiance (µW / cm2) and duration of exposure. The effectiveness of germicidal activity is wavelength dependent with a maximum around 265 nm which makes the potential germicidal efficacy of available UV-C LEDs greater than 254 nm emission Hg lamps.

The X-1-1-UV-3726 radiometer measures UV-C irradiance over a very wide dynamic range to beyond 100 mW / cm² with a resolution of 0.0001 µW / cm². It is calibrated for its spectral responsivity from 250 nm to 300 nm. Wavelength dependent calibration factors given in 5 nm increments are incorporated for measuring UV LEDs with known nominal wavelength. Additionally, a 254 nm calibration is included for Hg lamps as well as a general purpose 260 nm to 290 nm calibration for non-specific UV-C LEDs.

The X1-1-UV-3726 offers sufficient sensitivity to check for safety compliance and the effectiveness of personal protection equipment (PPE) in accordance with the accepted occupational exposure limit to actinic UV (ICNIRP). This requires irradiance levels to be < 0.2 µW/cm2 at 254 nm and < 0.1 µW/cm2 at 270 nm over 8 hour’s exposure. The handheld meter provides a real time display of irradiance or dose and includes a peak-hold function. The device may also be operated via its USB interface. Each meter is supplied with a traceable calibration certificate from the Gigahertz-Optik laboratory.