| 摘要 |
FIELD: physics. ^ SUBSTANCE: method of measuring flow rate of a liquid or gas involves: placing a negative temperature coefficient (NTC) thermistor in the stream of liquid or gas; measuring the initial resistance of the said thermistor; applying an energy pulse to the said thermistor in order to create a temperature difference between the thermistor and the said stream; measuring the start resistance of the thermistor immediately after switching off the said pulse and recording the start time for the said switching off, and calculating the value of cut-off resistance as a predetermined fraction of the difference between the said initial resistance and the start resistance; comparing the resistance of the said thermistor and the said value of cut-off resistance during cool off of the thermistor; recording the cut-off time when the said resistance of the thermistor reaches the cut-off resistance value; calculating the time interval between the said switching off time and the said cut-off time; determining the flow rate of the liquid and gas based on the said time interval. ^ EFFECT: high measurement accuracy, designing devices for measuring flow rate, whose readings do not depend on temperature of the stream in a wide range. ^ 4 cl, 4 dwg |
