Study of the noise in adsorption–desorption phenomena using the Allan variance and a quartz microbalance

A method to investigate the characteristics of noise of the adsorption–desorption phenomena is presented. The method is based on the Allan variance which allows the evaluation, in counting experiments, of noise spectral densities also in case of 1/f or Lorentzian noises. A first application to quartz microbalances coated with metalloporphyrins interacting with volatile compounds is here reported. The results indicate the presence of a 1/f noise component in adsorption phenomena.