| Active Area |
| The area in a device that actually collects light and converts it to electrons. In our data active areas which are circular are noted with one dimension and quadrilateral squares with two dimensions. Some PMT dimensions are described as 2p, square or hexagonal. |
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| AD Converter |
| Device for converting analogue signals into digital signals |
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| Amplifer/Preamplifier |
| A device for increasing the signal size from a photodector to make it easier to digitize. |
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| Amplifier bandwidth |
| An amplifier's bandwidth (BW) is defined as the difference between the upper and lower frequency cutoff points. The cutoff points are where the signal drops by 3 dB. |
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| Anode luminous sensitivity |
Anode luminous sensitivity is the anode output current (amplified by the secondary emission process) per incident light flux (10-10 to 10-5 lumens) on the photocathode. A tungsten filament lamp, operated at a distribution temperature of 2856K, is used to provide the incident light. Cathode and Anode luminous sensitivity are particularly useful when comparing tubes having the same or similar spectral response.
Anode luminous sensitivity is expressed in A/lm (amperes per lumen). Note that the lumen is a unit used for luminous flux in the visible region and therefore these values may be meaningless for tubes that are sensitive beyond the visible light region. |
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| Average/typical life |
Length of time the lamp usually operates to with 50% of stated specifications, including output energy, drift and fluctuations.
Using a lamp with a longer life leads to the reduction of maintenance cost as well as the time and running cost of equipment. Due to unique electrode structures with minimum electrode wear, Hamamatsu lamps feature unprecedented high stability over extended periods of operating time. |
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