Hi and welcome to the forum.
Besides the thermometer, you need a thermostat probe controlling the UTH so it doesn't burn your snake. Personally I'd use foil tape if the heat pad doesn't have any adhesive. It sticks better than electrical tape and is meant to deal with heat.
Here's a link on how to properly set up a glass terrarium:
http://ball-pythons.net/forums/showthread.php?t=201740
Hope this helps.
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