What are the factors that influence Background?

If the background value of the laser particle size analyzer is high on most detectors, but the 1st and 2nd units near the center are normal, the reason is often stains on the sample cell glass, dust on the lens, and residual particles in the medium. The medium temperature is lower than room temperature, causing fog droplets on the outer surface of the glass. If the detection unit close to the center of the detector, especially the 1st and 2nd units, is too high, it is generally caused by poor beam centering. If the background signal of all detection units is too low, it is most likely caused by a decrease in laser power or a shift in the filter pinhole. After identifying the cause of the background signal being too high or too low, the above problems should be eliminated to restore the background intensity to normal.