There are several factors that contribute to output voltage error due to the internal IC and external resistance. Factors within the IC include input offset voltage, input bias current, and input offset current. Factors related to the external resistance include the resistance and gain settings and relative resistance error. If the external resistance is too large the effects of the offset caused by the product with the input offset current increases. Also, the relative accuracy of the feedback resistance and input resistance that determine the gain affects the accuracy of the gain. When the gain setting is very high the input offset voltage which is a factor of the internal IC is amplified by the set gain and becomes the output offset.