UV Radiometer Selection and Use

There are several factors to consider when selecting a UV radiation instrument. These include the size of the instrument and the available space, as well as verifying that the instrument's response has been optimized for the specific UV LED being tested. It is important to note that radiometers designed for mercury light sources may not be suitable for UV LED light sources, so it is cirtical to communicate with instrument manufacturers to ensure compatibility.

Radiometers employ different response methods, and the width of the response of each band is determined by the instrument manufacturer. To obtain accurate LED readings, it is recommended to use a radiometer with a flat response within the ± 5 nm CWL range of interest. Narrower wavebands can achieve flatter optical responses. Additionally, it is advisable to calibrate the radiometer using the same radiation source as the one being measured to optimize its performance. The dynamic range of the instrument should also be considered to ensure its suitability for measuring the specific LED. Using radiometers optimized for low power sources or high power LEDs can result in inaccurate readings that exceed the instrument’s range.

Although UV LEDs generate less heat than mercury-based systems, they still generate some heat transfer. Therefore, it is important to monitor the temperature of the radiometer during static LED exposure and ensure that it remains within the recommended limits. It is recommended that the radiometer be allowed to cool between measurements. As a general rule of thumb, if the radiometer is too hot to touch, it is too hot to make accurate measurements. Furthermore, placing the instrument optics in different positions under the UV LED light may cause slight variations in readings, especially if they are in close proximity to the quartz window of the UV LED system. Consistent data collection methods are essential for obtaining reliable results.

Finally, users should follow the manufacturer’s guidelines for the proper use, care, and cleaning of the instrument. Regular calibration and maintenance of radiometers is necessary to uphold their accuracy.