Cleaning the ILS Matrix
Grease and dirt can make the ILS matrices harder for the sensor to read. So when necessary, clean the ILS Matrix with a soft cloth dampened with methylated spirit. Some solvents can damage the readability of the matrices, but not Methylated Spirit. Do not use cleansers containing solvents.
Be careful not to scratch the surface of the ILS Matrix. It can affect the performance of the positioning.