Excess gain of one (1x) describes a state when the measured sensing energy is at the amplifier threshold
If 50% of the original light energy becomes attenuated, then a minimum of 2x (two times) excess gain is required to overcome the light loss. Similarly if 80% of a sensorís light is lost to attenuation
(that is, only 20% of the sensing light energy remains), then an available excess gain of at least 5x is required.
If the general conditions of a sensing area are known, the excess gain levels that follow may be used as guidelines for assuring that the sensorís light energy will not be entirely lost to attenuation.
These guidelines include a safety factor for subtle sensing variables such as gradual sensor misalignment and small changes in the sensing environment