Problems with sumproduct

I'm having a bit of difficulty with sumproduct. I'm using it to work out the amount of time something is spending in a given temperature bracket. The data I have is a long list of temperatures taken at 30 second intervals. What I've done is have two values (e.g. 120 & 139.9999) and doing sumproduct using those.

So if the temperature values are in A1 - A100 and in B1 I've got 120 and in C1 I've got 139.999 the formula would be:

sumproduct((A1:A100>B1)*(A1:A100<C1))

The problem is that it seems to be counting double: in one case I've got 120 data points and it's counting 240 in total.



Is there anything I'm obviously doing wrong or is there an easy way around this short of simply dividing it by two?

Thanks in advance for any help.

Rob

OK, never mind. I spotted my own idiocy. I'd originally done it in 20°C steps and then decided to go in 10°C (with a formula for the steps = cell above plus 10). I'd changed the step value but forgot to change the upper value. So I ended up with 100 - 119.9999, 109.9999 - 129.9999 etc, so I was counting everything twice

Sorry for wasting everyone's time (I had spent 1/2 an hour trying to figure it out before posting, then just after posting noticed what I'd done).

Cheers,

Rob