- Index of detection electronics
- Introduction to electronics
- Introduction to data acquisition
Search the Dictionary
Pulse counting (called photon counting when making optical measurements) is used for very low signal levels when the signal consists of discrete voltage spikes. A discriminator on the input passes only voltage spikes above a set level (signal) and rejects voltage spikes at lower voltages (noise). In this way The pulse counter counts each discrete input pulse over some time period and outputs a count rate. Gated photon counting For repetitive pulsed signals such as optical fluorescence , the pulse counting can be gated to occur only during a fixed time window, similar to the signal integration by a gated integrator . Similarly to a gated integrator the gate can be scanned in time to obtain the transient. Example ApplicationsCW pulse counting Measurement of weak ion signals in a mass spectrometer when using an electron-multiplier tube or microchannel plate ion detectors. Gateded photon counting Measurement of a weak fluorescence signal after excitation with a laser pulse. Related Topics
Search the Dictionary
Search the Dictionary
