The RS925D Resistance Standard is a switchable, rack-mounted resistance standard providing 10 significant figures of resolution. Total value, 1.2 Mohm, achieved in 8 decades plus a 105 division rheostat (0.0001 ohm per division). Intiial adjustment of decades is ?20 ppm. Stability is ?(20 ppm + 1 mohm) from initial value for 1 year.