Abstract: A mass spectrometer having an ion accelerator and an ion detector utilizing a finite impulse response filter is disclosed. The ion accelerator generates an ion pulse in response to a start signal. A clock increments a register that indicates the time that has elapsed since the start signal. The ion detector is spatially separated from the ion accelerator and generates a measurement signal indicative of ions striking the detector. The measurement signal is filtered through a finite impulse response filter to form a filtered measurement signal. The finite impulse response filter has a filter function that depends on the impulse response of the ion detector. In one embodiment, the mass spectrometer includes a memory that is addressed by the register value and an adder. The adder forms the sum of the data value specified by the register value and the output value from the finite impulse response filter.

Abstract: A summed TOFMS having a filter for identifying detector outputs that are likely the result of noise rather than ions striking the ion detector. The TOFMS stores a plurality of data values at locations specified by a register that counts clock pulses. The filter receives the ion measurements from the ion detector and generates an output measurement value corresponding to each ion measurement. The filter sets the output measurement value to a predetermined baseline value if the filter determines that the ion measurement is noise, otherwise the filter sets the output measurement value to the ion measurement. An adder, responsive to the clock signal, forms the sum of the data value specified by the register value and the output measurement value and stores the sum in the memory at the location corresponding to the register value.