I am unsure of how to interpret the uncertainty given for a Multimeter I have been using. Everything is listed as follows ±(0.8%+10). I have never seen uncertainty listed this way, with a +"x" after the percent uncertainty. What range does this correspond to exactly, -10.8% to 10.8% or is it -0.18% to 0.18%? Here is a link to the datasheet: Digital Multimeter Datasheet. Thanks!
It means that there are two parts to the error. One part is proportional to the reading (0.8%), and the other part is a absolute error (10).
For example, if a reading is 174, then there is 174 x 0.8% = 1.4 proportional error, plus the 10 fixed error for a total error of 11.4. A reading of 174 therefore means the actual value is in the range of 162.6 to 185.4.