Test strips measure the oxidation potential of the water. Chlorine, bromine, non-chlorine shock and other things have an oxidation potential. The color chart for reading the results are calibrated for what the strips are designed to test for. So, yes, bromine will give a positive reading on chlorine test strips, HOWEVER, the color chart will not be accurate as to how much bromine is in the water (I believe you have to multiply a chlorine reading by 2.25 to get the accurate reading for bromine).