Comparison of mass flow rate sensors for ginning stripper-harvested cotton

Real time mass flow sensors are needed at various locations' in the cotton gin if process control is to reach its full potential, Several devices, inc luding belt scales, light array bars and a microwave flow meter were evalua ted for their suitability in detecting the flow of cotton and the mass flow rates of stripper harvested cotton. The readout from the truck scales was used to provide the lot weight for the study. Although equipment problems p revented us from resting the accuracy of the scale units under varying rate conditions, these units should provide the most accurate method of measuri ng mass flow. The mechanical nature of the scale units, however limits thei r usefulness in commercial gins which use primarily pneumatic systems to co nvey the cotton. The microwave-based sensor was unsuitable for measuring ma ss flow but did provide art excellent indication of the presence of pow in the pneumatic pipes. The signal from the light bar array correlated very we ll with the mass flow rate of the cotton through the pipes (R-2 = 0.98) and requires only minor modifications to the pipes used to convey the cotton. All devices need estimates of moisture and trash content to improve accurac y.