@jamieha
It's often difficult to use tools such as a tuner to check percussive sounds because of their texture & their short length.Therefore it's common practice to do it by ears. A Frequency Analyzer like the free "Span" from Voxengo can also help by displaying the frequency & the corresponding note reference, pointing your mouse cursor over the transient note in Span Gui will display this information at the top.
Beside this there's pros & cons about tuning your drums in key with the track. Pros: the technique is supposed to make the all mix more harmonic & smoother for the ears, cons: having too many of the same frequencies dueling for space in the mix can give you some issues & will require some work to avoid the all mix to sound dull in the end.