Ya that's a good pic.. A infrared laser thermometer is handy as well to check your hot spot temp as the uth won't help ur ambient temp much at all.. And unless u have a thermometer with a probe all ur going to get is ambient..

My set up I'm trying to get dialed in by Sunday uses 2 stick on thermometers for ambient hot/cold side a hygrometer for humidity and the herpstat + with the probe between the tank and uth