title: [Air flow rate converter errors depending on the manufacturing precision].
abstract: Among the most promising converters of air (gas) flow rate into pressure differential employed in systems for the respiration parameters measurement should be counted the ones based on the viscous friction resistance, made in the shape of plane-parallel channels formed by packs of plates, with pressure take-off along sections of the laminary flow from each channel via orifices and collectors Individual converters of the same type and size may differ substantially from one another in their conversion ratio, depending upon the degree of precision with which the instruments are made, and then mainly due to deviations in the thickness of the plates (the height of channels). In order to exclude such variations and to obtain a standard signal it is recommended that the making of the instruments  should include a tuning operation of the clear opening area in the resistance, or correction of the distance between the pressure take-off points. This will make it possible to utilize standard secondary convertes and thus cut down the cost of measuring systems incorporating such devices.
mesh_terms: D000403:Airway Resistance; D003951:Diagnostic Errors; D005069:Evaluation Studies as Topic; D006801:Humans; D012123:Pulmonary Ventilation; D011786:Quality Control; D012129:Respiratory Function Tests / Q000295:instrumentation*
vernacular_title: Pogreshnosti preobrazovateleĭ raskhoda vozdukha, sviazannye s tochnost'iu ikh izgotovleniia