mõõtevahend, mis on ette nähtud kahe sama sagedusega elektrilise suuruse faasinurga mõõtmiseks, kus ühe suuruse faasinurk on tugifaasinurk, instrument intended to measure the phase difference between two alternating electrical quantities of the same frequency, one of which is taken as the phase reference, device for measuring the difference in phase of two alternating currents or electromotive forces