[Cell definitions and equations] [Student assignment handout] [OpenOffice and Excel Version]
A simulation of measurement of light intensity by a photomultiplier tube (PMT). Includes the effect of load resistance, integration time, wavelength, light flux, applied voltage, and phototube temperature on signal and signal-to-noise ratio of light intensity measurement with photomultiplier tubes. Students compare difference types of phototubes, measure spectral characteristic, observe effects of amplifier overload, display resolution limits, phototube overload, determine lowest flux that can be measured, attempt to improve the SNR by cooling the phototube. There are versions for DC operation (with a continuous light beam) and AC operation (with a chopped light beam). The DC version shows the signal and signal-to-noise ratio numerically; the AC version shows the signal and signal-to-noise ratio graphically.
When used in a lecture-demonstration environment with a computer video projection system, where it is often difficult to use the keyboard data entry in a darkened room, these models can be operated using only the mouse-activated on-screen sliders, pop-up menus, and radio buttons.
DC operation (with a continuous light beam): pmtDC.wkz;
AC operation (with a chopped light beam): pmtAC.wkz.
Wingz player application and basic set of simulation modules, for windows PCs or Macintosh
OpenOffice and Excel Version
Other simulations that
employ a photomultiplier detection system:
Signal-to-noise ratio of absorption spectrophotometry
Fluorescence Spectroscopy Signal-to-Noise Ratio
Comparison of Calibration Curve Fitting Methods in Absorption Spectroscopy
Effect of Slit Width on Signal-to-Noise Ratio in Absorption Spectroscopy
Scanning Fluorescence Spectrometer
Dual Wavelength Spectrophotometer
Effect of Slit Width on Emission Spectroscopy SNR
Spectroscopy of Atomic Absorption
[Return to Index]
Photomultiplier handbook (PDF format)
Getting the best out of photomultiplier detectors (PDF format)
Building your own photomultiplier system
Student handout (WingZ Version)
Light Measurement with Photomultiplier Tubes
Computes the detector signal current and signal-to-noise ratio, given the phototube characteristics and the incident light power (watts) on the photocathode. Includes source flicker, photon, and thermionic emission noise.
Assumptions: Quantum efficiency of photocathode, gain per stage, and collection efficiency are independent of light level and detector current.
Download spreadsheet in OpenOffice format (.ods)
Download spreadsheet in Excel format (.xls)