PIR False Alarm?


I have a couple indoor Sentrol PI6000 PIRs attached to my 2 month old Elk M1G. I have been logging activity via Homeseer. Last night I received 2 motion entries in my log about 1 hour apart. No exterior doors were activated and all my windows were locked. I am fairly sure no one was in my house. Wife said she wasn't up, kids have door sensors and we have no indoor pets. So, what are some common causes of false triggers? I'm just wondering what I should do.

2 sensors that tripped? or 1 sensor that tripped twice?

near heat vents or any usual weather?
1 sensor tripped twice.

Not directly near any vents.
It was raining pretty hard, but hey, It's Washington!
Go to the keypad system zone diagnostics under user menu 8,6,3 and see what the zone voltage is reading. EOL resistor zones should be around 7.5 volts, and normally closed zones should be 0 volts. Any voltage out of these values by more than 2 volts could be a problem in the wire, wiring, or sensor.

Was you having any winter time lightning during the rain storm? Sometimes lightning transients can make sensors trip.
* Tested the voltage, it looks good.
* No lightning - but lots of rain
* Don't think there are any mice - and wouldn't they be too small to set one off anyway?

AND... It happened again when my wife was in town today. Just one ON/OFF, so it isn't like there is someone walking around. Also, the motion in the other room doesn't trip and a person would probably go to more than one room. I don't want to rely on this if it is going to be flaky. Any other thoughts?
I use motion sensors to track any potential incursion of mice, but I do use cheap ones, not sure if the better models would pick them up.
Hmmm. Interesting. I've seen one case were PIRs installed in the summer, falsed in the winter when the sun came in at a different/lower angle than when the units were installed. But you said it was raining at the time.

Any leaks in the roof? :unsure:

Is there anything in the PIRs field of view that could cause a sudden temp change? Any movement. I have a plant in my Great Room that has leaves around 8" long by 5" wide. The suckers around 8' high now, and a leaf falling from the top will trigger the nearest PIR if the sensitivity is at max.