Sure it isn't a combo just thermometer. Hygrometers need to be calibrated they typically are crumby out of the box. salt test is easy and simple.
ebay item number 270744134684
hygrometer
http://www.neptunecigar.com/pr/analo...RC=ShoppingCom
I actually bought my hygrometer from a local store. The price was slightly higher but about the same with shipping. I got a better price the second time I went in and bought 12 of them, they thought I was odd but hey 25% off I was happy. Two of them were more than 8% off so I adjusted them down. I check them every 8 months so far only one needed re-calibration. Most wouldn't bother to change them if they are off by less than 5% (ok I admit it I have to have them all the exact same, no not necessary but I just can't stop myself!!!)