8 ms·
None of these are sold anymore in the country where I live. They are all optical nowadays.
by haarts 3y ago
None of these are sold anymore in the country where I live. They are all optical nowadays.
- flandish 3y agoHere in the US we use both (three types really) for different scenarios; they both have benefits in terms of “quickness” to detect smoke, fire, or heat. Source: am firefighter