IES LM-61-20 PDF Download

The IES LM-61-20 standard addresses the challenges faced in accurately measuring the performance of luminaires in real-world conditions. While laboratory testing provides controlled environments for precise measurements, field measurements are often influenced by various factors that can deviate from predicted performance levels. This standard specifically focuses on outdoor HID luminaires (such as mercury vapor, metal halide, and high pressure sodium lamps) and low pressure sodium lighting equipment with core and coil ballasts.

The document outlines the potential factors that can cause differences between calculated and measured illuminance and luminance values of these types of lamps and luminaires. It acknowledges that field conditions do not allow the same level of control and accuracy as laboratory conditions. Factors such as luminaire orientation, test distances, ambient temperature, electrical supply and regulation, and lamp stability are identified as potential variables that can affect the measurements. However, it is important to note that this document does not provide solutions to these challenges, nor does it encompass all possible variables that may be encountered in the field.