It can be on almost all the time when the screen is on. So, if you turn on the phone and it is not on sleep mode(like when you press the lock button), it should be on.
It's also one of the things that a funky OS load can affect. I had issues with my ATT refurb's proximity sensor and when I loaded 7.1 it worked fine. I had not had issues with the sensor on the previous unit, even when it had the same OS the refurb came loaded with.
It can be on almost all the time when the screen is on. So, if you turn on the phone and it is not on sleep mode(like when you press the lock button), it should be on.
Sounds like you're trying to imply the sensor should be active even when a call is not in progress? If so, I don't think that is correct behaviour. Afaik, the sensor is only there to detect face proximity so the screen can automatically turn itself off during a call (supposed to prevent your face/ear from touching the screen but some of us still have that problem anyway!)
It has no use other than on a phone call. A 9900 I had once glitched on 'always-on' mode and I can't tell you how quickly the battery drained on that.
Sounds like you're trying to imply the sensor should be active even when a call is not in progress? If so, I don't think that is correct behaviour. Afaik, the sensor is only there to detect face proximity so the screen can automatically turn itself off during a call (supposed to prevent your face/ear from touching the screen but some of us still have that problem anyway!)
It has no use other than on a phone call. A 9900 I had once glitched on 'always-on' mode and I can't tell you how quickly the battery drained on that.
Yeah this was my concern. My battery has always drained fast but it was especially fast just recently and I noticed the proximity sensor was constantly on, guess that was why.