This paper presents a technique to evaluate for the standard uncertainty of temperature uniformity. In general, when considering the temperature test chamber as a constant temperature chamber that has achieved an arbitrary uniform temperature, the uncertainty at that achieved temperature can be separated into the two factors of chronological temperature fluctuation in time, and spatial temperature fluctuation, referred to as temperature uniformity. Temperature uniformity is represented through two methods: temperature variation in space base on the center of the working space, and temperature gradient considering the entire working space. To represent a linear integer mathematical model applied to evaluate temperature uniformity. The numerical illustrations and results substantiate that the model proposed is useful to simultaneously consider x and y axis when determining temperature uniformity. Moreover, we found that the linear integer model made a significant impact on uniformity of the temperature chambers.