To have good background status, the laser particle size analyzer
should simultaneously satisfy the following five points: low value (1-4), short length (within 20 channels), sloping shape (decreasing gradually from left side), positioned at the very left of the axis, and stability. Factors of background state include:
(1) Poor alignment;
(2) Dust or fog on the sample cell;
(3) Impurity in the medium;
(4) Aged laser.
In addition, factors such as measure without medium, too much dust in the air, and dirty lens can also lead to abnormal background state. If background is abnormal, the following should be checked:
• Cleanness of sample cell and the lens;
• Whether there is medium in the sample cell;
• Whether the medium is pure;
• Laser brightness;
• Communication between the instrument and the computer.
After checking the original cause of the background abnormality, the fault should be eliminated in time to restore the background to normal state, and then the particle sizing can be carried out. If you can't find the cause of the background abnormality, you need to contact the particle size analyzer manufacturer