For adhesive bonding and curing through UV radiation, LED spotlights and gas discharge lamps with liquid light guides, whose high irradiance enables curing and polymerization within seconds, are used.

Exact measurements in order to monitor the irradiance and dose are required for the process control. Here, the UV sensor is exposed to the high irradiances and temperatures, which could lead to an impairment of the measurement results. The sensor series XT („eXtrem Temperature“) has been developed for this critical application. The XT sensors are suitable for up to 50.000 mW/cm² and operating temperatures of 150°C. At the same time, the XT sensors are compact and thus flexibly usable where needed.

This is possible due to the separation of sensor-head and sensor-electronics. The XT sensor with its excellent cosine correction guides the light through a light guide into the calibrated sensor-electronic, which is integrated in the handpiece. That way, just like with all our high quality radiometers, several sensors can be connected to one hand-held meter.

For your application you can select between four sensor types. The XTR guides the light through a stainless steel rod into the handpiece and is very quickly usable. Due to the distance between the sensor head and the handpiece, the user is protected from the radiation!
In the XTF, the sensor head is connected with the flexible light guide in order to enable measurements in places that are difficult to access. Both sensors have a height of 10 mm without any impairment of the measuring precision. 
The diameter of the XTR and XTF sensors is 40 mm. By the way, sensor and handpiece are flat so that even here the measurement is optimal and reproducible. XTR and XTF are thus the first choice for UV spot bonding.

For even smaller installation dimensions, we offer the XT sensors as side-on or head-on version. Dimensions of 13 x 13 x 40 mm allow for measurements in places that are extremely difficult to access.

All XT sensors can be connected to the radiometer RM-12 for the measurement of the irradiance or to the RM-22 for measurements of irradiance and dose. Compared to the RM-12, the RM-22 has a higher resolution, an expanded measurement range, data storage in an internal memory of 4 GB, a data interface and the illuminated graphic display.


For precise measurements, we calibrate the sensors to the process light source or the used LED wavelength. For this, more than 20 radiation sources are available in our accredited laboratory. Of course, all our sensors are factory-calibrated, long-term stable and precise upon delivery. Optionally we deliver the XT sensors with a DAkkS calibration.


Operation temperature 0 to 150 °C
Storage temperature -10 to 150 °C
Humidity < 80% non-condensing
Light guide 0,3 m / 1,5 m
Cable length 2 m
Measurement range 0 - 20 W/cm²
  0 - 2 W/cm² (opt. 2)
  0 - 50 W/cm² (opt. f. RM-22)
Resolution 0,01 W/cm²
  0,001 W/m² (opt. 2)
  0,01 W/cm² (opt. f. RM-22)


UVC 200 - 280 nm
UVB 280 - 315 nm
UVA 315 - 400 nm
UVA+ 330 - 455 nm
UVBB (broad-band) 230 - 400 nm
VISB 400 - 480 nm
VISBG 400 - 570 nm
LUX 380 - 780 nm, V(λ)