A method for measuring a voltage (V, V n), in particular a full voltage and/or a partial voltage (V n), between a first terminal and a second terminal, wherein the first terminal is spatially separated from the second terminal and wherein the voltage (V, V n) creates an electric field between the terminals (1a, 1b), the method comprising the steps of arranging at least one first electro-optical light transmitting element (2, 2a) in the electric field between the first and the second terminal, passing light through the first electro-optical light transmitting element (2, 2a), measuring at least one first signal (S n) from the first electro-optical light transmitting element (2, 2a) and further measuring a second signal (S n ') from a second electro-optical light transmitting element (2, 2a, 2b, 2c), wherein both signals (S n, S n ') are periodic functions of the voltage and have a relative phase shift other than zero, deriving the voltage (V, V n) and resolving an ambiguity in the deriving of the voltage (V, V n) from the first (S n) and the second signal (S n '), characterized by the steps of: (i) using the first signal (S n) as a base signal (S n) indicative of the electric field over the first electro-optical light transmitting element (2, 2a), (ii) using the second signal (S n ') as a reference signal (S n ') for resolving the ambiguity in the deriving of the voltage (V, V n), (iii) determining from the first signal (S n) at least two hypotheses (h +, h -) corresponding to different possible voltage values (V n h+, V n h-) of the voltage (V, V n), (iv) deriving an expected value (S n h+, S n h-) of the second signal (S n ') for each of the hypotheses (h +, h -), (v) comparing the expected values (S n h+, S n h-) to a measured value of the second signal (S 2), and (vi) taking a binary decision between the hypotheses (h +, h -) by validating that hypothesis (h +, h -) for which the expected value (S n h+, S n h-) is closest to the measured value of the second signal (S n '), wherein a waveform of the applied voltage between the first terminal and the second terminal is reconstructed using a plurality of electro-optical light transmitting elements (2a, 2b) without requiring a quadrature signal for each electro-optical light transmitting element (2a, 2b), wherein the electro-optical light transmitting elements (2a, 2b) are arranged in series in an axial direction between the terminals (1a, 1b), and wherein further only one signal (S n) per electro-optical light transmitting element (2, 2a, 2b) is measured. (i) using the first signal (S n) as a base signal (S n) indicative of the electric field over the first electro-optical light transmitting element (2, 2a), (ii) using the second signal (S n ') as a reference signal (S n ') for resolving the ambiguity in the deriving of the voltage (V, V n), (iii) determining from the first signal (S n) at least two hypotheses (h +, h -) corresponding to different possible voltage values (V n h+, V n h-) of the voltage (V, V n), (iv) deriving an expected value (S n h+, S n h-) of the second signal (S n ') for each of the hypotheses (h +, h -), (v) comparing the expected values (S n h+, S n h-) to a measured value of the second signal (S 2), and (vi) taking a binary decision between the hypotheses (h +, h -) by validating that hypothesis (h +, h -) for which the expected value (S n h+, S n h-) is closest to the measured value of the second signal (S n '),