Illuminometers for measuring brightness in lux, fc or cd/m². Some Illuminometers are equiped with internal memory or ²a data logger to record the measurments. The measurment of light intensity with these illuminometers are, each day, becoming more important in the workplace where protective screens are needed. The technique of measuring enviromental conditions, to which the measurement of light belongs, also occupies a lead position in scale of importance. Illuminometers with data loggers as shown inour on-line store, are highly regarded especially due to their cosine correction of the angle of incident light. These illuminometers have memory to store measured values, and software to analyse readings.