The MS DC parameter controls a dc offset voltage applied to the quadrupole mass filter.
This voltage affects peak widths and ion transmission. It has its greatest effect on the transmission of higher mass ions.
| Polarity | Minimum | Maximum | Default | Typical |
|---|---|---|---|---|
| Positive | 0 | 20 | 3.0 | 0.0 to 5.0 |
| Negative | -20 | 0 | -3.0 | -5.0 to 0.0 |
During manual tuning, the MS DC voltage can be ramped to find an optimum value, but ramping the MS DC voltage is not a reliable way to find an optimum value. Ramping the MS DC is used primarily as a diagnostic tool.
Ramp defaults and limits are:
| Default (volts) | Limits (volts) | |
|---|---|---|
| Start (From) | 0 | 0 to (Stop - Step) |
| Stop (to) | 13 | (Start + Step) to 13 |
| Step Size (by) | 0.1 | 0.1 to (Stop - Start) |
| Default (volts) | Limits (volts) | |
|---|---|---|
| Start (From) | -13 | -13 to (Stop - Step) |
| Stop (to) | 0 | (Start + Step) to 0 |
| Step Size (by) | 0.1 | 0.1 to (Stop - Start) |
See Also