How Luminescent Dissolved Oxygen Works:
Our Hach dissolved oxygen instruments are equipped with a measuring LED that emits a pulse of blue light and a photo diode as a light detector. The instruments are also equipped with a sensitive luminescent coated spot that is exposed to the sample.
- The measuring LED emits a pulse of blue light which irradiates the back of the oxygen sensitive spot. The coating material reacts with luminescence and emits a pulse of red light where the intensity and time delay are measured.
- When oxygen is present in the sample stream and contacts the coating, the intensity and time delay of the luminescent light emission are changed.
- The more oxygen molecules come into contact with the coating, the lower the intensity and the shorter the duration of the red radiation. These changes in the profile curve are used to determine the measurement.
