Setting co with gas analyser

[djtez]

This is more a question of can it be done with this type of reading, the mot bay at my work (kwik-fit) a have my car on the mot ramp often as it's the only it will get on,
Am
Looking to sort it out a bit on fuel but the reading
It gives me is in a % factor.. I.e 1.2% etc. Being a pre cat by law it's maximum 3.0% but pushing that aside am wanting ti know a rough area where ma car should be for maximum pase.

Thank you in advance for any replies