...yes the Bushido Cowgirl is back and in need of some information I am having trouble tracking down.

First FAB III. It is listed with a cost in Street Grimoire (Force x 25,000 per 1 cubic metre). I know what it basically does but never remember it having a Force Rating. So looking for what the rating refers to as yes it is very expensive (but I have a character that might be able to secure some).

The next is how would the yield of a Thermobaric device (FAE) determined in 5E? There were specs back in 3E based on the amount of fuel the device contained, but nothing in R&G about it (even though FAEs are mentioned in passing in a couple sourcebooks). Basically the same character as mentioned above has a 208 L drum FAE she acquired and for an upcoming job it might come in real handy (she already has the method of delivery figured out). From the description Atomisers sound more like a "room fogger" that fills an area with explosive vapours which is then detonated producing no "fallof" of power within the cloud's radius. An FAE is an airdrop device designed to produce an extremely powerful shockwave similar to a low yield tactical nuclear detonation (hence why in some circles they are referred to as the "poor man's nuke")

In SR4, the rating was used for the opposed test when a FAB III cloud was using its energy drain power. It was also used to determine when the cloud would split into 2 smaller clouds. One would assume it does the same in 5th ed but hey, it's 5th ed and it was probably just a copy/paste error. Now it likely confers some wireless bonus or sets some limit to social tests or something equally inane.

4th ed didn't really deal with thermobaric devices beyond one mention in Eurowar Antiques as an option to add to an obsolete Russian missile called the Vikhr. In that case it did 18 P damage with a -6/-2 AP depending on target (people vs vehicles). There was also an explosive atomizer like you mention that does the same task as the one in 5th ed. Unless someone else knows of a better example for 5th ed, I think in this case you may have extrapolate from what a FAE device does in 3rd ed and convert it to 5th ed.

...thanks. Yeah Fab III sounds icky because if you have any awakened members on your team it might go after them.

For FAEs sort of worked out the specs between researching RL thermobaric devices 5e demolitions, and the information in 3e (Man & Machine). In RL a hydrocarbon mist FAE (Kerosene or Petrol) has about 4 times the power of an equivalent amount of TNT. Since 1L is 1 KG in mass using that and the Modified DV formula in 5e (R&G) it would be ridiculously powerful (288 DV in a 208 m diameter cloud falling off at -1 for every 1 M from the edge of the cloud out to 144m) so just used the base rating for TNT (5) which calculates to 72 DV which is still pretty powerful. Again within the cloud damage of an FAE is constant so that's a pretty big whopping area taking 72 DV..

Going on a really big bug hunt.