10 Вольт измеряютинтересно это:
Our three old Lab DVMs 1x Fluke 8502A and 2x HP 3456A, that came to us about 19 years ago and that were never adjusted in all those years, exhibit offsets of -13.6 ppm, 12.7 ppm and 3.1 ppm according to the measurements in Stuttgart. (10 V DC measurements) Those DMMs did receive some maintainance like recapping power supplies and the like. The difference between the two HP 3456A was measured as 6.5 ppm in 2008 and increased to 9.6 ppm since then. Good news that confirms Franks statement of "1 ppm/year" being within reach technically. Of course, if someone needs certificates for legal reasons, that's another story.
Т.е. моя идея найти 3 3456А - за цену менее чем 100, починить\исправить откалибровать + дешево\разумный стандарт, я думаю это предел для домашнего использования. Кстати все приборы почти выровнялись - я подозреваю это влажность , температура примерно та-же +19. но лето и дожди ... вот и получил изменение ... влажность показывает 45 -50 было 30 ( чегото там ) +2ppm ..
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