Pinayev, I. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-204-2 10.18429/JACoW-IBIC2019-WEPP042 English 642-644 WEPP042 electron emittance solenoid experiment controls Contribution to a conference proceedings 2019 2019-11 https://doi.org/10.18429/JACoW-IBIC2019-WEPP042 http://jacow.org/ibic2019/papers/wepp042.pdf Measurement of the dependence of the beam size on profile monitor vs. strength of a focusing element is widely used for measurement of the beam parameters. Such measurements are mostly used for the separate planes and assumption that beam satisfied Gaussian distribution. In many linear accelerators the transverse beam dynamics is coupled between planes and distribution is far from the Gaussian. We developed measurement technique of the second moments of beam distribution which does not rely on any assumptions. The theory and experimental results are presented.