Measuring equivalent background illumination of image intensifier assembly by low light level illuminometer

Equivalent background illuminance is an important parameter which directly reflects the background illuminance and the background noise of image intensifier assembly. It is analyzed and tested respectively in this paper that the method to measurement equivalent background illuminance based on luminance meter and illuminometer. The results show that the equivalent background illuminance of image intensifier assembly with gallium arsenide photocathode can be measured by the luminance meter or the illuminometer. However, because the background illuminance of image intensifier assembly with aluminum gallium nitride photocathode would be lower than the effective measurement limitation of the luminance meter, it can only be measured with a low light level illuminometer. Error analysis result of using an illuminometer to measure the equivalent background illuminance shows that the measurement error of this method is 9.1%, which can meet the requirements of the equivalent background illuminance measurement of image intensifier assembly. The research of this paper can provide an effective solution for testing the equivalent background illumination of more image intensifiers assembly.