The detector in the LC/MS is a high-energy-dynode (HED) electron multiplier. The detector receives the ions exiting the quadrupole mass filter. It generates a signal current proportional to the number of ions it receives. This signal is passed to the electronics for amplification and processing.
The HED is the voltage applied to the beginning of the high-energy-dynode electron multiplier. It is applied in kV.
All active components of the HED electron multiplier are located out of the direct path from the end of the mass filter. This greatly reduces the noise caused by neutral particles.
The detector features a replaceable electron multiplier horn. The HED electron multiplier can also be removed from the LC/MS in order to clean the high energy dynode. Both of these procedures are included on the Agilent 1100/1200 Series LC/MS or CE/MS Maintenance CD-ROM. Both procedures should be required only infrequently.
| Minimum | Maximum | Default |
|---|---|---|
| -10 kV | 10 kV | 10 kV |
See Also