Photomultiplier Detector
The monochromator receives light from the hollow-cathode lamp through the flame together with the light emitted from the flame. The signal arising at the detector from the flame emission will be rejected and only that from the hollow-cathode lamp will be accepted. The detector used almost universally is a photomiltiplier tube whose current output corresponds to the intensity of the light falling on its photocathode. This feeds the amplifier and output device, which displays the measured signals.