I was playing on a 1 on 1 server and had a health of ten so my Pl dropped. When it reached 0 the other guy said he couln't find me. If there was a way you could get your PL to 0 you wouldn't show up on the scouter.
In fact after ten thousand my PL just disappeared altogether!
I think the scouter should be able to zoom in and out, so you can see wider areas.