 BIPM:The IPK in three nested bell jars |
| NIST:K20, the US National Prototype Kilogram resting on an egg crate fluorescent light panel |
| BIPM:Steam cleaning a 1 kg prototype before a mass comparison |
| BIPM:The IPK and its six sister copies in their vault |
| The Age:Silicon sphere for the Avogadro Project |
| NPL:The NPL’s Watt Balance project |
| NIST: This particularRueprecht Balance, an Austrian-made precision balance, was used by the NIST from 1945 until 1960 |
| BIPM:The FBBatakan:Nbhyph2 flexure-strip balance, the BIPM’s modern precision balance featuring a standard deviation of one ten-billionth of a kilogram (0.1 µg) |
| BIPM:Mettler HK1000 balance, featuring 1 µg resolution and a 4 kg maximum mass. Also used by NIST and Sandia National Laboratories’ Primary Standards Laboratory |
| Micro-g LaCoste:FGBatakan:Nbhyph5 absolute gravimeter, (diagram), used in national laboratories to measure gravity to 2 µGal accuracy |
