Portable handheld luxmeter for measuring illuminance, luminance, PAR, irradiance (across VIS-NIR, UVA, UVB and UVC spectral regions or measurement of irradiance effective according to the UV action curve). In addition to instantaneous measurement the instruments calculate the acquired measurements time integral Q(t). Storage of maximum, minimum, average value and the integral Q(t), RS232 C output for data transfer in real time to a PC or printer. Functions: REL, HOLD and auto power off which can be disabled, IP 67 protection degree. LP471.. series probes with SICRAM module are suitable. The probes and cables for data download have to be ordered separately.