Hi Ralph! Glad you found us! Sorry your first post is about a "problem!"
There are several reasons your two probes could be reading differently. First, if they are in different locations, they could be reading different. Secondly, if one of them is close to bone, it could read different. The only true way to tell is to test both probes. First, test them in a glass of ice water and make sure they read 32°. Next, test them in boiling water and make sure they read ~212°. If the SI probe doesn't read those properly, you can program in an "offset" for the probe reading. Let me know if you need to do that, and I'll help.
Now that you're here, how about telling us about yourself in the Introductions section (like smoking experience)? You might also add Ralph, and your town, to your signature line (in the Forum Profile), so we remember who you are in every post.
Great to have you with us!!