Question

Can someone please describe how background count is taken into account when measuring half-life

Answer 1

You must measure the background radiation with your instrument with no source present and determine the counts per minute or hour or what ever time although longer is better. In determining the half-life subtract this count rate from each count rate you made with the source present. You can determine the half-life by plotting count rates at various times on log linear paper until your source has decreased sufficiently . The line will be straight if only one isotope is present. Determine the slope of this line. the half-life is 0.693/slope in units of the abscissa of the plot.