PaulS:
I was seeing parentheses where I would have put them, not where you didn't put them.You are dividing by a. If a is ever 0, you are doing A BAD THING.
You SHOULD be using parentheses to make it clear how that equation is to be evaluated.
Ok, I have put the equation like this now:
float sensor1 = beta /(log(((1025.0 * 10 / a) - 10) / 10) + beta / 298.0) - 273.0;
instead of:
float sensor1 = beta /(log((1025.0 * 10 / a - 10) / 10) + beta / 298.0) - 273.0;
And it seems fine. Do you agree with that?