| 摘要 |
A mass spectrometer or ion mobility spectrometer comprises a first vacuum chamber 2, a first vacuum pump 8, an inlet orifice 6 (e.g. a capillary or aperture) arranged between an ion source and the first vacuum chamber 2, and signal means for indicating that said inlet orifice 6 is partially blocked or clogged when a detecting means determines that the pressure within the first vacuum chamber 2 has fallen below a threshold. The detecting means may be a pressure gauge for the first vacuum chamber 2, or it may comprise monitoring a reduced gas flow rate pumped out of the first vacuum chamber 2 by the first vacuum pump 8, a reduction in the amount of power or current drawn by a second vacuum pump 10 connected to a second vacuum chamber 4, a reduction in the rotation speed of the second vacuum pump 10, or a reduction in a temperature of the second vacuum pump 10. |
