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photon flux maintenance

[2.23.1]

The ratio of the photon flux of an electric light source at a given time in its operational life to its initial photon flux.

Notes:

  1. Photon flux maintenance is usually expressed as a percentage.
  2. For the purpose of measurement, the electric light source is assumed to be operated under specified controlled conditions. In field measurements, the value may vary due to uncontrolled conditions.
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