This application note gives a procedure for performing quick checks on an Analog to Digital Converter (ADC) system gain, offset and linearity.  The technique uses a ramp signal from a function generator to stimulate the system, including signal conditioning at the ADC front end.  A mixed signal oscilloscope (MSO) is used to look at both the signal into the system, as well as the digital signals out of the ADC to evalsuate conversion.  In this case, the MSO is used to uncover a problem with offset error.