29 RECORDING OF METEOROLOGICAL ELEMENTS General Meteorological data can be obtained by direct readings of measuring instruments, and by instruments providing ab bcontinuos record of the parameter overtime. Instruments for direct readings are usually simpler and cheaper than the latter, but the type of information obtained is of instantaneous character and the amount of data which can be collected depends to a large extent on the availability of trained staff. Recording instruments have been designed for practically all meteorological parameters using various physical principles as described in the previous sections. Generally they can be divided into mechanical and direct