Calibration stability test after 2 years time, of all ITTSB reviewed multimeter

[Kiriakos GR]

Today made one inspection at the batteries which powering up my reference voltage source (yearly inspection), and found the opportunity to perform one large scale test.
What I was looking to discover was how my meters hold their calibration stability after two years time.

FLUKE 28II  arrived to me 7 October 2010 (personal purchase)
Agilent U1272A ..... 17 June 2011
BRYMEN BM869 ..... 7 November 2011
Agilent U1273A ..... 27 April 2012
HIOKI DT4282  ...... 21 March 2013

I performed this quick test by warming up the meters for 15 minutes prior taking the pictures.
One DC calibration stability test is not a full test, but it does have it value.
What matters to me is that all of them are in pristine condition and their manufactures worth to feel proud for their products.

U1272A from it arrival it was one count less at the last digit compared to U1273A, therefore time did nothing to it regarding this difference.