Noobie.. How can I tell if my humidifer works?

I guess I'll go try and pick up a cheap hygrometer. My humidor was 40, and all the hygrometers i've seen are 20. I shouldve just gotten a 60 dollar desktop humidor with a built in hygrometer.
It hasnt been seasoned. The inside is lined with foam and leather, so I'm not sure about if it needs to be. I'm thinking of just selling this one and buying a desktop humidor. Kind of a mistake buying this instead of a real cedar one.