A measure which indicates how closely the coordinates of a point in Ordnance Survey map data agree with the true National Grid coordinates of the same point on the ground. As the true position can never be known exactly, the statistic is quoted relative to the best known position determined by precise survey methods.
Found on
http://www.encyclo.co.uk/local/20195
A measure of the uncertainty of an instrument reading compared to that of a primary standard traceable to a National standard.
Found on
https://www.encyclo.co.uk/local/20687
No exact match found.
