Conditional Formatting numbers only, not text

I have a spreadsheet where I record water sample results,
I want to add conditional formatting to highlight cells that exceed the limits for the parameters being tested,
However some results come in the form of <0.10, so even if my limit is 1.0, any cell with a less than symbol will also get highlighted,

Is there anyway around this?

Try replacing it in you CF rule, something like

=--(SUBSTITUTE(A3,"<",""))<0.1

So do I enter this into the conditional formatting?
I want to keep the less then symbols, generally any cell with one has it because it is very low and should not be over the limit
I just don't want it highlighted

Actually I figured out what you meant,
Thanks so much!