Opt: 001 & 002. Powerful, easy-to-use analysis software for HP 9000 Series 200/300 Computers. 0.6 ppm for 24 hours in dc Volts. 2.2 ppm for 24 hours in Ohms. We will do our best to resolve any issues.
This DMM was designed by the same generation of engineers that put people on the moon, but contrary to the moon program it is still relevant (and selling by HP/Agilent/Keysight) today. You get true 8.5+ digits of resolution at affordable price.
My only note - remember about 4 hours warm-up, do daily self-calibration if you want to stay within 4/8ppm DC accuracy