Help using my light meter for 16mm film

[Cale Boys]

I'm beginning to want to shoot more 16mm film lately and I'm curious if my light meter is set-up correctly and a couple questions regarding some features. 

I've currently got a 400ft roll of 500T, so my settings are: 500 ASA, 25fps, 180 shutter. Why is it in my sunny lounge room still giving me a reading of 2.8? Also the little 00 next to the F-stop reading, I can either go + or - . If I were to add a ND of 1.2, would I then + 1.2 to tell my light meter I'm using an ND with 1.2? 

 

 

[David Mullen ASC]

I have no idea what the [00] area is for.  Are you sure your shutter angle is 180 or your shutter time is 1/50th for 25 fps?

I find the best way to check my meter is to set it to 50 ASA at 1/50th and go outside and point it at the sun at midday in clear weather. You should get f/16, maybe a bit more (I always get f/16.3 at 1/48th).  This follows the Sunny 16 rule of photography.