[Usefulness of the PEFR (peak expiratory flow rate) measured with Wright's apparatus for the diagnosis of chronic respiratory tract diseases in children].

The measurement error was estimated in 5 peak flow meters of Wright serving for measurements of peak respiratory flow rate in children. The estimation was carried out by two methods: 1) comparing the agreement of measurements with the apparatuses connected to steady flow generator. 2) by means of a biological experiment making possible estimation of the apparatuses as well as the subjects carrying out the measurements. The first method, although disagreeing with the design of the apparatus, makes possible sufficiently accurate estimation, is simple, rapid. The second method demonstrated that the only source of differences between the measurements were instruments and not the personnel carrying out the measurements.