What happens at a pain management clinic during a psychological test?

I have chronic pain due to an accident in 2004. After 2 surgeries,(and another in two weeks), physical therapy, and treatment through my general practitioner, I have been refered to a pain management clinic. My first appointment left me hopeful. They scheduled me for routine psychological testing appointment that they do for all patients they are going to take as patients. I have never had testing of this sort. What does it entail and what should I expect?