Hello I plan to use an arduino in my car (temperature control for LPG vaporisation and engine) easiest positioning will gives -20 (winter in the mountains though i can get away with the system not working as long as it is not distroyed) to 80° requirement (need to work at such temps) a little more work and we get to 60° max. The question is will it survive under the hood ? Who has tried similar use ? when will it fry/ freeze ? Any experience someone ? Any component to change ? Philippe
Most semiconductors are specified to work in a 0 to 70C ambient. However, you can get the more expensive military specified devices to work up to 80C. So look to replace all semiconductors and the crystal. The capacitors will probably be all right as they continuously degrade with increasing temperature, despite having a so called maximum temperature.
The hotter something is the less reliable it is and the quicker it will ware out. (if it has a ware out mechanism).
A car is a very hostile environment and probably not one in which to try something like this. Commercial car electronics undergo extensive hot / cold testing to remove any weak spots in the design.
I use to sell automotive electronics and under the hood is not where you want to be. It's hot, cold, wet, corrosive and it vibrates worse than a rocket in flight. There may even be gravel and such flying around if you go off-roading!
If at all possible, bring your electronics inside the passenger compartment, away from the top of the dash (nowhere near an airbag!) and out of direct sunlight, and use one of the existing hole+grommet passage into the engine compartment if you need to wire up to a sensor in there.
Don't forget to fuse your power supply and to keep in mind the difference between a battery line (always connected but can drain your car battery at the most inconvenient moment) and an accessory line (battery safe but no power when ignition off).
And my car’s hood is considered one of the hottest (very well insulated by composite fairings…)
Then there will be no escaping wiring the NTC with looong good quality wires and hoping for the best.
Or is there some better king of sensor to use ?
Speaking of sensors one of the purpose of this arduino would be to regulate the butane/propane mix temperature on top of the engine.
(stable temperature allows for a better control of richness of air fuel mix thus less fuel used plus it’s a nice regulation project with plenty of coding to do to optimize regulation. now water temp is from 75 to 90° LPG goes wilder from 15 to 80°).
That would require the following sensors
-water temp before evaporator
-water temp after evaporator
-water temp after radiator (maybe)
-vaporized LPG temp
-bloss (kind of carburator) temp
-throttle position sensor
of which the vaporized LPG temp is the trickiest I would like it to be fast, 5 seconds response time, and it would be working in vaporized butane propane mix which would suggest covered sensor (though strangely it is not mandated by regulation in cars).
Any sensor suggestion…
M'afraid I dunno much about engine management or under the hood sensors for those applications. I believe, however, that there are specialized websites and forums which should have some content for you, but perhaps not linked to Arduino specifically.
Sensor manufacturers might have some application notes that could be of help, as well.
In between the commercial (0-70C) and military grades, there are also industrial (-40 - 85C) and automotive (-40 - 130C) temperature ranges. (Those ranges are approximate, and depend on the particular part and manufacturer.)