The Z.L. experiment consists of 3 photometers which are mounted rigidly into the s/c with orientations of about 15°, 30° and 90° south of the s/c – XY-plane, which coincides in orbit with the ecliptic plane (see Fig.1). Helios is spinning uith 1 Hz, and the integration time of the experiment is 513 revolutions. The 90° – photometer always looks to the south ecliptic pole and one revolution of the s/c is divided into 8 sectors to get information on the polarization of Z.L. The polarization is measured by a fixed polaroid foil within the photometer which is rotated by the s/c. In the other two photometers one revolution is split into 32 sectors with different angular resolution. Near the antisun where the gradient in Z.L. intensity is small, the sector length is 4 times the length near the sun (see Fig.2). In these 2 photometers the polarization is obtained by 3 differently oriented polarization foils moved by stepping motors. Intensity and polarization of Z.L. is measured in 3 different colors, which are near the international UBV – system (Ažusienis and Straižs 1969), the effective wavelength shifted by about 100 Å to the blue end.