The Danfoss Photocell LD/LDS sensors are based on the phototransistor principle in connection with an amplifier and convert light from the flame into a current.
The flames characteristics and the location of the sensor influence the size of the photocurrent created in LD/LDS. For this reason, LD/LDS is available in two sensitivity levels.
If a strong enough signal is not produced with the selected sensor, select a sensor with a higher sensitivity level.
If the flame cannot be detected at the highest level of sensitivity, use the Danfoss UV sensor. To determine the quality of the signal, use the following guidelines.
For no flame/darkness, the value must be ≤ 5 μA; for flame/light the value must be ≥65 μA.