What diesel fumes alarm?

[mudnomad]

I have an Eberspacher diesel heater in my camper. Professionally fitted etc but still I would like to have some sort of alarm for this 0.00001% that something gets disconnected and I am sleeping with the fumes getting inside.
What sort of alarm works for that? Is that carbon monoxide?

[Jonboy_t]

Would be carbon monoxide you’d need