An Approach to Design a Wireless Air Flow Transmitter Using Flex Sensor

In process industries, air flow rate measurement and transmission are usually performed by various passive conventional sensors. Here, air flow rate for moderate flow applications is sensed by resistive type flexible bend sensor having the characteristics of light weight, tiny size, cost-effective, fine linearity and also good repeatability. The flexible resistive type bends sensor which acts as a cantilever beam derives the linear relationship between air flow rate and the change in resistance of the sensor in the form of an electrical signal. For transmission purposes, the generated electrical signal passes through the electrical communication system which is not permeable in hazardous and inflammable areas of the process industry. Henceforth, for the data transmission purpose, Internet of Things (IoT) is being introduced in industries for avoiding explosions due to electric spark and also the real-time data is transmitted throughout the globe with the help of internet. The proposed air flow transmitter has been theoretically analyzed in this paper and the relationship of air flow rate with a transmitted voltage signal has been derived. The experiment has been performed on the fabricated prototype air flow measuring unit. The experimental results are presented in the paper which is matched with the theoretical one. The proposed IoT based air flow transmitter unit shows linear characteristic with good repeatability. The higher value of air or any clean fluid flow rate can be measured by this prototype flow transmitter by only changing the dimensions of the cantilever type bend sensor.