Channel Photomultipliers

CPMs offer a new technology for more accurate and efficient photon detection. For decades, researchers have relied upon glass photomultiplier tubes (PMTs) for measuring and analysing light emitted at levels so low that detection of single photons is required. However, PMTs have severe limitations, and as applications grow in number and sophistication, so does the need for more precise and efficient instruments. This is why PerkinElmer introduced its line of (CPMs) which exceed the capabilities of PMTs by eliminating many of the disadvantages.

PerkinElmer CPMs are available in 3 sizes - please see table below. Devices in each range are optimised in their sensitivity to detect wavelengths from near UV to IR (115nm to 900nm). Software is available from IGI Systems for the RS-232 enabled Photon Counting Modules - click here for more details.

The technology

CPMs operate according to the same general principles as PMTs, but are built from different materials and lack the PMTs internal parts. Photons enter both devices through an entrance window and hit the photocathode, inside which the photons are converted into electrons, which are emitted into the vacuum. CPMs have a simplified structure, and operate with far less background noise. In the CPM, the vacuum channel is virtually silent, and dark counts originate from the photocathode alone. The lower background level of a CPM results in a high dynamic range and significantly better detection limits.