Does false alarm happen to on-line dissolved gas monitor?
There are two possible reasons for false alarm, which are: 1). Problem due to the monitor itself; 2). unsuitable alarm threshold settings. Practically, the later situation is the main reason for which the false alarm sometimes happens to the composite gas monitor. For example, the user normally sets up the recommended H2 alarm threshold which is 150 mL/L. If one installs a composite gas on-line monitor whose relative sensitivities to H2 and CO are 100% and 18% on a transformer with zero concentration of H2 and 800mL/L concentration of CO, the reading of the monitor would be as high as 144 mL/L (0*1+800*0.18) which is very close to the alarm setting. The false alarm could be triggered soon if the alarm setting leaves unchanged.
