| Observation | Possible causes | Recommended solutions |
|---|---|---|
| High event rate | Air bubble in the sheath filter or flow cell | Remove the air bubble from filter |
| Sample is too concentrated | Dilute the sample | |
| Sample flow rate is set on HI | Set the sample flow rate to MED or LO | |
| Threshold level is too low | Increase the threshold level | |
| PMT voltage for the threshold parameter set too high | Set the PMT voltage lower for the threshold parameter |
