Megger/Biddle 247000 Digital Low Resistance Ohmmeter, Biddle The 247000 Digital Low Resistance Ohmmeter is a highly accurate instrument proving simple, practical, and reliable low resistance measurements in the field. The 247000 is also ideal for production quality control, engineering, and development applications. It operates on the four-wire measurement principle, thus eliminating lead and contact resistances. The 247001 features a internal battery and charger for maximum portability.