A validated calibration method for hydrogen peroxide vapour sensors

A method of calibrating hydrogen peroxide vapour sensors is described which is based on the well-defined saturated vapour pressures of hydrogen peroxide over its aqueous solutions at fixed temperatures. The calibration technique was developed for use with amperometric gas sensors but could be applied to other sensor types. The method can be used over the entire range of vapour pressures that are likely to be of practical interest in the context of isolator sterilisation and has been reliably validated by quantitative volumetric analysis. The method depends not only on the well understood underlying principles but also on the solution of practical problems associated with ensuring full saturation of the carrier gas stream and, simultaneously, the elimination of aerosol droplets which might otherwise interfere with the calibration.