This chapter provides test procedures with measurement recording tables, test equipment setups, and verification tables to verify the measurement accuracy of the MA241xxA and MA242x8A USB power sensors. Test and verification is performed by comparing the sensor to a reference sensor with a specified cal factor and linearity performance or uncertainty. The reference sensor should be calibrated by a reputable standards laboratory using NIST instruments with low published measurement uncertainty values. Sensor test limits in these procedures are set appropriately to the specified comparison equipment. All tests must be performed at an ambient temperature of 20 ºC to 25 ºC to optimize the power sensor’s performance.