Yale HSA3070 - Smoke Detector, does anyone know what sensor type?

[sharpener]

I want to fit a smoke detector in my loft space where I will shortly have a PV inverter installed. It would be convenient to add a Yale HSA3070 to my existing alarm system, but I can't seem to find out the sensor type anywhere on the web (even the Yale site does not say).

Does anyone know for sure whether it is ionisation, optical or heat?

Sorry to post here but the alarm pages are locked(!)

TIA

 

[alarm man]

i believe they are optical types