Thermovisi is an instrument used to visualize and detect the hot spots contained in an object using infrared technology. Thermovisi is useful for knowing the condition of the equipment contained in the switchyard. Temperature measurement on an object also has a weakness in obtaining the actual temperature of an object being measured. This is because the emissivity value of an object varies from 0 to 1. The heat temperature on substation equipment is a parameter that is seen and analyzed changes every time. This is related to system reliability and protection at the substation. This final project discusses the validation method to test that the measurements made are accurate and precise by using manual calculations and using Microsoft Visual Studio C # software according to the parameters used. The results obtained are 68 connections on the terminal in good condition, 5 connections at the terminal under conditions of maintenance checks and 1 connection at the terminal under immediate repair conditions. For the emissivity of the equipment at the substation using 1 type of material, the emissivity value varies due to several factors, with the accuracy of each transformer bay 1 to transformer bay 3 being 97.44%, 95%, 99.97% . And for the precision value of 0.61%, 1.43%, 0.58%, respectively. The results of the measurements are stated to be accurate and precise so that the calculation validation test method can be used.