Fig. 11

Comparison of theoretical relative uncertainties (2σ) for Pb isotope analysis using amplifiers with noise of 4 × 10⁻¹⁶ A/s (equal to Johnson–Nyquist noise for amplifiers with 10¹¹ Ohm resistors; blue lines), and amplifiers with noise of 6.15 × 10⁻¹⁷ A/s (equal to 0.15 of Johnson–Nyquist noise for amplifiers with 10¹¹ Ohm resistors, and representing noise performance of ATONA amplifiers shown in Additional file 1: Table S2; red lines). Solid curves with smaller symbols correspond to 10-min signal integrations, dashed curves with larger symbols—to 60-min integrations. Baseline measurement time is 10 min in all cases. All other parameters are the same as in Fig. 10