hi DM2 , thank you for your response , my problem is how can i solve this equation k c At exp(-ζdt)/dt2 = k c Ad exp(-ζ dd)/dd2 , in order that i determinate
''dt=the distance at which the detector can detect the design fire''
my questions :
how can i determinate the values of Ad and dd ?
what deas it means ''listing fire test '' ?
could you share a link that explain this issues ?

thank you in advance.