HP AGILENT KEYSIGHT 3458A DIGITAL MULTIMETER Opt. 001 Ser # 2823A02567 $5200 PayPal Will list elsewhere in a couple of days but wanted this list to see first Working, Fully Refurbished, New Calibration, Guaranteed . Very good condition, fully refurbished, all new quality electrolytic aluminum can capacitors on both outguard and inguard power supplies (approx. $200) . New Digi-Key Dallas NVSRAMS installed on gold sockets. Previous SCAL constants preserved and copied (approx. $190) . Option 001 installed using fresh Digi-Key 256k SRAMS upgrading A5 PN: 66505 to 66515 . Important - Brand new Keysight "factory fresh board" A3 ADC Assembly PN: 66513 ($1488.33) . Important - Replaced power line mains filter with new Schaffner FN9233-3-06 . Instrument FIRMWARE upgraded to latest Revision 9 updating 6 ROMs to PN: 88890 thru 88895 . Both pin and connector of ALL slip-pin connectors unseated, individually cleaned and reseated . Well-aged A9 Reference board rock solid and now performs as well or better than most Option 002 boards. Cal? 2 values over two decades have only changed 4.3 PPM . A9 Reference LTZ1000ACH heater temperature modified from 90C to 60C per Lineal Technology for better long-term stability. The HP PN: 66509 A9 board accommodates this mod at extra component location X411 . Many week-long continuous graphing through GPIB to verify both long-term (A9 Ref) and short-term (A3 ADC) stability. Results far better that HP Service Note 18A would suggest. . Typical weekly deviation plus-minus 0.2 PPM, stability average (drift) 0.00 PPM if lab temperature remains plus-minus 0.5C, Internal instrument temperature difference from Cal10 temperature is included while graphing, NPLC=500 . Original Operating, Programming and Configuration manual as well as Quick Reference Guide and Front Panel Operation foldout are included. Assembly-Level Repair manual, Calibration manual and CLIP manual available on-line or I can email pdf files Free 1-year artifact calibration. You pay shipping both ways. Calibration instruments used: HP 3458A, calibrated Jun.07,2018 by Keysight Primary Standards Lab, Loveland (see photos) Fluke 732A calibrated Jun. 18, 2018 (10V Ref for artifact calibration) Fluke 742A-10K characterized Jun. 18, 2018 measured 10.000069K (10K Ref for artifact calibration) Fluke 5450A characterized Jun. 18, 2018 used to verify all resistance ranges Keithley 2002-MEM2 calibrated Sept. 05, 2018 by Tektronix Irving, TX (2nd control ref for graphing) HP 3325B-002 calibrated Sept 2018 used to verify SCAL points (HP 3458A used as transfer standard) Datron/Wavetech 9000 calibrated Jun. 19, 2018 (HP 3458A used as transfer standard for all performance verification points) Pictures can be emailed direct if interested. Regards, Don