Can I measure AC voltage with the U1241B/U1242B Handheld Digital Multimeter (DMM) if there is a DC offset?

Yes, you can measure AC voltage with the U1241B/U1242B Handheld Digital Multimeter (DMM), even if there is a DC offset. Just perform the AC measurement in manual ranging mode by pressing the RANGE button. (Under the auto-ranging mode, the meter may keep scanning across its range for input signal that consists of AC+DC value).