[header] How to measure dc offset [title] Purchase a multimeter. [step] A multimeter is a handheld device for measuring electrical current, resistance, or voltage. Multimeters are available in either digital or analog models, and can sport a variety of different features. 
The important consideration when choosing a meter to measure dc offset is the lowest available voltage range. [substeps] Because dc offset readings will be quite small (usually under 100 mv), you need a meter with a small range (sensitivity) so that the readings will register correctly.