METHOD OF CALIBRATION OF NOZZLE AND DEVICE FOR CALIBRATION OF NOZZLE Russian patent published in 2018 - IPC G01F25/00 

FIELD: measuring equipment.

SUBSTANCE: invention relates to the field of flow measuring technology and is intended for transferring a unit of gas volume flow from the reference nozzle to a calibrated with minimal influence of the transfer function of the comparator on the final transmitted unit of flow. In the method for critical nozzle calibrating, through which gas is passed through the calibrated reference nozzles and the calibrated nozzle in a critical mode and the gas flow rate is measured, according to the invention, two gas flow rates are formed from at least two sets of parallel and previously calibrated reference nozzles, greater and smaller than the estimated flow rate of the calibrated nozzle, alternately connect to a flow indicator – a comparator – a calibrated nozzle and each set of calibrated reference nozzles, the gas is passed in a critical mode and accordingly the pressure drop across the comparator is measured when each set of calibrated reference nozzles is connected and the pressure drop across the comparator is connected when the calibrated nozzle is connected, and the flow rate of the calibrated nozzle is determined from the expression:

where Q1, Q2 – expenses of reference nozzles (less and more than verified), ΔP1, ΔP2 – pressure drops on the comparator when working reference nozzles, ΔP is the pressure drop across the comparator when the calibrated nozzle is being operated, and the pressure difference at the comparator is measured at a portion of the developed laminar flow.

EFFECT: increase in the accuracy of transmission of the unit of flow, stability of the readings in time and independence of mechanical resistance, as well as reducing the influence of the comparator on the accuracy of the result.

6 cl, 1 dwg