Abstract: A manually operable measurement apparatus for measuring level, temperature and transition zone between two different liquids. The measurement is carried out by letting a probe through a sluice and valve means into a tank. The probe is combined in one unit and is sensitive to both relative dielectric constant and loss factor as well as the temperature of the surrounding medium(s) to be measured. The invention is particularly suitable for measurement in tanks having an internal pressure being different from the atmospheric pressure and in explosive environments.