BCO, as far as I understand there are recommendations (European-wide?) as to the amount of smoke which should cause a smoke detector to operate. I don't know what these recommendations are specifically.
The amount of smoke is measured by it's obscurity to light. Obviously there must also be recommendations as to type of smoke (Apollo use the description 'grey smoke') and, I would imagine the intensity of light, used when testing.
Most detector manufacturers 'pre-set' their detectors to operate at a specific level, although the Apollo Discovery Multisensor has 'user pre-settable' modes that cover levels within the 1.1-4.2% per m, as per my previous post.
I've just also also remembered that the Apollo Discovery Optical also has these 'modes' and, on checking, I can confirm that these cover the range 1.4 - 2.8% per m.
I know of no detector where total adjustment of the sensitivity is provided for adjustment by the 'user'.
I know of no control panel that allows you to adjust the response of a smoke detector by varying the % obscuration.
Some analogue addressable panels allow some means of adjustment of sensitivity (in as much as at what point the panel reacts to the information the detector is sending to it) but I know of none where this is measured as a % obscuration. In all events, I would imagine that the range of adjustment made available is always only within the range of the recommendation mentioned in the fiirst line of this post.
It might be a good idea for you to contact a detector manufacturer for more advice.
In my fire alarm servicing days, I well remember numerous occasions where unwanted alarms were attributed to invisible amounts of smoke from small bonfires flowing through open bedroom windows.
