X1-1-RCH-116-4

In UV-A and blue light radiation curing, liquids (e.g. inks, coatings and adhesives) are excited by irradiation with high-intensity UV-A and blue light radiation. The curing process is activated by photoinitiators absorbing the UV or blue light energy which triggers the polymerization reactions (crosslinking). In the past, only gas discharge lamps provided sufficient intensity withinthe photoinitiators’ wavelength range for this purpose. Today, these are increasingly being replaced by LEDs that emit in the UV and blue spectral range. In order to ensure optimal triggering of the polymerization, the irradiance of the UV lamp must be set in accordance with the corresponding process parameters. In continuous operation, the constancy of the irradiance must be regulated and readjusted when necessary depending on the aging of the lamps. The required UV radiometer, especially its detector, must be able to withstand the high-intensity UV and blue light radiation as well as the relatively high temperatures.

Radiometer with detector for measurement of UV-A and blue light

The X1-1 radiometer from Gigahertz-Optik features an RCH-116-4 detector and is ideal for measurement of the irradiance of high power LEDs in the UV-A and blue light range. The device can accurately measure irradiance levels of up to 40,000 mW/cm². One of the outstanding features of the RCH-116-4 detector is its proven concept of a passive radiation absorber coupled to a UV sensor. This provides stability even in high temperature and intense UV radiation environments. In addition to the passive radiation absorber, the device also has a cosine-corrected field of view. The sensor’s housing also serves as a handle. The battery-powered X1-1 optometer supports a usable dynamic range from less than 1 mW/cm² to 40,000 mW/cm² thanks to its high-end signal amplifier. It can be used to perform precise measurements of up to 5 standard LED wavelengths for which the detector was calibrated for active irradiance. In addition to the CW measurement function, the device also has a dose measurement function. The radiometer can be used with other detectors from the RCH series. e.g. for gas discharge lamps.  Remote control of the device is possible via its user software and a software development kit is offered for integration of the device in the user’s own software.

Calibration of the X1-1 RCH-116-4

One essential quality feature of photometric devices is their precise and traceable calibration. The RCH-116-4 detector is calibrated for standard LED wavelengths: 365 nm, 375 nm, 385 nm, 395 nm, 405 nm, and 430 nm. The calibration is performed by Gigahertz-Optik’s calibration laboratory that is accredited by DAkkS (D-K-15047-01-00) for the spectral responsivity and spectral irradiance according to ISO/IEC 17025. The calibration and calibration values are confirmed by a calibration certificate for every detector.