This paper presents a method for estimating the value of uncertainty associated with the measure by an electronic measurement system, as metrological component in the process of design and construction of a measuring system generic. In this specific case of a precision magnetometer Hall. The method used is by comparison with a team pattern. It also determines the error as provided by the different components of conditioning system of measurement system. The procedure poses a value for the uncertainty to the extent of the magnetic field of 0.8% and 0.2% error. The mistake is made by the different components of the system instrumentation.