@b1gduk: Its an interesting question whether multi-stage deployment of the airbag might be disabled by this mechanism as you allude to.
It certainly sounds worthy of investigation if you typically have younger/petite folk in the front passenger seat.
Actually, I meant to remove that post and start again. For some reason there is a problem with those readings so please ignore.
I took some fresh readings today in proper daylight with 4 people of various sizes. Here are the results.
109KG - 1.7K Ohms - Me
78 KG - 2.3K Ohms - Neighbour
58 KG - 2.7K Ohms - Wife
15 KG - 7.5K Ohms - 4 Year Old
The readings would wander a bit but those are the ballpark figures. Also the position you sit, ie towards the front of the seat or right at the back and also how much pressure you are putting on the front part of the seat with leg position affect the readings to some degree.
So they are not linear but I cannot be sure we were all affecting the same sensor pads under the cloth.
I then proceeded to check what reading I would get it with more weight so I say my wife on my knee. Went down to 1.2 ish.
I then pulled up on the seat to see if I could get a max sort of reading for heaviest and that read 1.12K not saying the Hulk could get a lower reading but to be honest, I dont think it would be much lower.
I then put my hand on the sensor and removed pressure slowly and saw readings going up the high 19.xK but never 20K. That is probably like a wallet on the seat in the correct position to affect a pad.
I guess from these results then one could conclude that to actually get a 10K reading you would have to be a baby or not sat down properly.
So baring in mind there would be no point in a weight sensor unless there was also control over the speed of inflation of the airbag ( micro switch would be cheaper for on/off) then 10K might not be the best compromise although I am sure it would work as it is possible to get readings up to nearly 20K but that is feather light touch with hand on cushion.
I would say any reading beyond 20K should register a fault with the ECU as open circuit or something ?
So this is where I would like some technical person to contribute because the way I see it I would rather the airbag not deploy inadequately if an adult ie WIFE was in the sat. Children this small should not really be in the front seat anyway or you should disable the aigbad with the switch on the side of the dash.
So I personally would be much happier seeing a 2K Ohm Resistor there.
Hope this is useful and may spark a debate :~)
Oh Disclaimer. I am offering observations, not suggestions , any remarks that could be interpreted as a suggestion was expressed without proper command of the English language. I do not want anyone following my observations and finding out the hard way they are flawed. If you choose to use them you do so at your own risk.