What are the typical % Gain or EHT values for hollow cathode lamps?

These values are typical results only for a standard single element lamp, based on the standard operating conditions for each lamp. Both coded and uncoded lamps should give the same performance. They are not guaranteed specifications as such, but have been issued as a guide to typical performance. Some variation from these figures would be considered "normal". This information has been provided as a guide and to assist with routine trouble shooting.

Notes:

1. The SpectrAA 55 / 220 FS were fitted with the standard wide range photomultiplier (type R 446).
2. The SpectrAA-880 was fitted with a wide range, high sensitivity photomultiplier (type R 955).
3. Instruments fitted with higher sensitivity photomultipliers will generally achieve lower gain values than shown above.
4. The % gain or EHT (photomultiplier voltages) observed during optimization may differ from these values for the following reasons:

• • A multi-element lamp may be fitted
  • A different photomultiplier may be fitted
  • Sensitivity of a photomultiplier can vary
  • Sample compartment windows may have deteriorated (e.g., from dust build up) reducing light throughput and increasing % gain (EHT) values
  • Some accessories, which clip the optical beam and reduce light throughput, may be installed e.g., graphite furnace, vapor generation absorption cell
  • Age of the lamp. Older lamps will show higher values, as the emission intensity is reduced as the lamp ages
  • The optical parameters selected are no longer the default values e.g., switching to a less intense wavelength will change the value
  • Zeeman GFAA instruments have a different optical configuration, and use different optical parameters which may alter the value