Abstract:
This research describes air flow measurement device based on microcontroller .The design of the air flow meter includes sensors which allow the microcontroller to measure three parameters – air velocity , pressure and temperature . The software compensates the measured air flow for both temperature and relative pressure.
The air flow meter software is almost entirely written in BASCOM –AVR -1.11.9.0 . The program consists of a main program and six cases ( Air flow meter _set , Temp _set , Pressure _set , and input value ), ADC channel ( 0 ……..5) . The design also includes seven-segment LED displays and variable resistance to allow selective display of airflow, temperature and pressure.
Airflow is continuously compared with a program-defined set point if the measured airflow exceeds the set point, an output relay will be energized.
The percentage measurement error (% error) is calculated from the following equation :
% error = %100(Qmt – Qref ) / Qref
Where Qmt and Qref are the Airflow meter rates from the measurement being evaluated and the reference flow meter .
