Press release submitted by Gigahertz-Optik.
Gigahertz-Optik, Amesbury, Massachusetts, a manufacturer of innovative UV-VIS-NIR optical radiation measurement instruments, has developed a line of UV spherical irradiance detectors for the measurement of effective spherical ultraviolet germicidal irradiance (thus fluence rate) applied in air and water sterilization applications employing low and medium pressure Hg, pulsed Xenon lamps or LED based sources. Versions of the RCH-XXXs type detector would also be useable in any full immersion UV/VIS/NIR measurement or monitoring application.
Since the UV signal is received over nearly a full 360°, more like the actual target of irradiation, it provides a better gauge of UV dose or fluence rate than the standard planar irradiance detector.
Planar cosine corrected UV detectors are the industry standard for measuring UV irradiance impinging on flat surfaces in UV germicidal applications and they work well in this role. However, for upper room UV germicidal irradiation set-ups using wall, corner and ceiling (pendant) mounted UV fixtures the aerosolized airborne pathogen (viral, fungal, bacterial) is not necessarily a one flat surface target. It is three dimensional, take a droplet for example. In a properly designed set-up irradiation should engulf the target from all directions. Now a direct measurement of spherical irradiance is possible eliminating cumbersome and time consuming calculation of fluence rate based on multiple planar irradiance measurements or chemical actinometry.
The RCH-XXXs series spherical UV detectors are configured based on the particular light source employed. For example, for low pressure Hg lamps the detector would be designed and traceably calibrated for use at 254nm. Or the detector may be set-up for and calibrated at several key LED wavelengths with the user selecting the appropriate LED wavelength by menu function on the radiometer used.
The measurement range of the radiometer will depend on the detector specifications and those of the particular meter. For example, the X1 Radiometer with RCH-122s for 254 nm will measure from an NEI of 1.2 μW/cm2 to max 50 W/cm2.
The detectors can be used in combination with any Gigahertz-Optik filter radiometer. For the widest dynamic range the P-21 Radiometer is recommended. Adaptation of the detector to work with existing radiometers should be discussed with the factory.
All RCH type detectors are uniquely designed to withstand and remain stable in high intensity UV and heat environments. The sensitive components (bandpass filter and photodiode) are encapsulated upstream from the irradiation zone. A light guide connects the filter detector capsule to the input optic directing the optical radiation piped through to it at much lower intensity. See schematic diagram below.
Both rigid and flexible fiber light guide versions are available.
For more information, visit www.gigahertz-optik.com.
