How to Measure UV Radiation

Hi, I am currently doing some tests on light (UV) activated polymers. Sunlight did the job very well during summertime. As we are in winter now (southern hemisphere) the natural light intensity is not enough. I built an artificial source of UV using a 400W- Pro Osram HQI-T lamp from which I removed the shielding glass and placed it in a light fixture (reflector) from which I also removed the glass. This fixture was then fixed to the inner wall of a sealed cabinet and the bottle containing the polymer was placed in front of the light source, 50 cm apart. The experience did very well, but the polymerization speeded up at a point, creating bubbles in the polymer; which is undesired. My idea is to measure UV at different distances from the lamp in order to determine at what distance / UV amount the bubbling does not happen. Do you think this is feasible? I also evaluated the possibility of placing a temperature sensor in the polymer in order to cool it down when it reaches a certain temperature.