R6 is able to be populated with a 0 ohm resistor for testing purposes to easily allow testing of the common mode voltage range vs supply. R7/R8 and R9/R10 are voltage dividers between V+ and V- to allow a simple fixed voltage input to the IA. R3 and R4 allow either input to be easily connected to ground. CL and RL allow for testing to data sheet load conditions, or CL and RO can be used to apply an output low pass filter.