Analog-to-digital converters are essential components in modern systems which gather data from the real world to be used, after signal processing, in many ubiquitous applications. This work addresses the effect of the presence of additive noise in the test setup when characterizing these electronic devices using the Histogram Test method. The precision with which the converter transfer function is estimated is directly related to the amount of noise present, the number of data samples acquired and the sinusoidal stimulus signal amplitude. Here an analytical expression that quantifies this precision as a function of the test parameters is given to be used by the engineer when designing the test.