Dendrochronologically-matched Irish Oak samples covering the period of 200-4000 BC are measured at intervals of 20 years with a high precision system, then compared to other published data and used to provide a ¹⁴C time scale calibration. Inter-laboratory comparison has shown good agreement in the results. The ¹⁴C measurements presented in this paper, combined with previously published measurements, provide a 6,000-year high-precision curve for the conversion of ¹⁴C dates to dendro-age. For related work, see also <i>AATA</i> <b>Vol. 15, Abstract No. 230</b>, PARIS No. 86892, <b>Vol. 18, Abstract No. 1240</b>, PARIS No. 82287, <b>Vol. 21, Abstract No. 151</b>, PARIS No. 74165, and <b>Vol. 22, Abstract No. 88</b>, PARIS No. 70094. -- AATA