Calibration standard BN-LH250

irradiance

Calibration standard lamp for use as reference spectral irradiance standard One of the most common optical radiation measurement quantities is irradiance. This measures the radiation power incident on a reference surface in W / m². The photometric equivalent of radiometric irradiance is illuminance which is measured in lux. Calibrated light sources are required to calibrate instruments for measuring spectral irradiance (spectroradiometers) and illuminance (luxmeters). These sources must have a continuous spectrum over the spectral sensitivity range of the instrument to be calibrated and a calibration traceable to a National Metrology Institute (NMI). The lamps used must meet high requirements with regard to their short- and long-term stability. Halogen lamps are most commonly used for calibration. These offer a continuous spectrum from approximately 250 nm to 2500 nm. The lamps must be operated with a constant current. To calibrate the measuring instruments, the calibration lamp is arranged at a predetermined distance from its input optics, typically a cosine diffuser. Reference standard BN-LH250 The reference standard BN-LH250 is based on a 250 W halogen lamp. This lamp exhibits excellent short-term and long-term stability due to its very stable filament. The quartz envelope itself is frosted for a more uniform radiation. The lamp base of the BN-LH250 fixes the lamp by means of a clamp. The electrical connection is made via two laboratory sockets on the stand. The protective cover with a transparent crosshair target enables the precise and reproducible alignment / positioning of the reference standard in the measuring arrangement.