Since the conditions in the duct can vary, the data are recorded at the beginning, middle and end the sampling period for each sampling point.
Reference:
Erasmus, T. 1973. A computer programme for evaluating the dust burden of dust-laden gases flowing in large ducts. http://hdl.handle.net/10204/12933 .
Erasmus, T. (1973). A computer programme for evaluating the dust burden of dust-laden gases flowing in large ducts Retrieved from http://hdl.handle.net/10204/12933
Erasmus, TC A computer programme for evaluating the dust burden of dust-laden gases flowing in large ducts. 1973. http://hdl.handle.net/10204/12933
Erasmus T. A computer programme for evaluating the dust burden of dust-laden gases flowing in large ducts. 1973 [cited yyyy month dd]. Available from: http://hdl.handle.net/10204/12933