On another forum someone wanted an alarm for excessive water/coolant temperatures; so there were several suggestions including 'in hose' temp measurement. This is what I posted:-
"Now that I've spent another few minutes thinking about it; a water PRESSURE warning light/alarm is the way to go and not water temperature.
Coolant temperature is NOT engine temperature!
Whilst measuring temperature of water seemed to make sense at the outset.
What temperature do you set it at as a warning?
The system is designed to operate at or above 100 deg C.
However:
For any given system, temperature of coolant is limited by its maximum pressure which is determined by the coolant filler cap.
For every individual car the mixture of coolant :: water; and the coolant boiling characteristics, will be somewhat unique and will even vary from time to time within the same car.
The only constant will be what pressure will crack open the filler cap. (Caps do vary in themselves too); including leakages due to crud build-up [eliminated by annual inspection ].
An alarm/ flashing LED on the instrument panel linked to a preset pressure will inform the driver of imminent coolant loss be it from impending over heating or the start of a gasket leak.
:lol: Miser's Must-Have Monitors Ltd" :lol: