On the reliability of instruments for environmental monitoring: some practical considerations.

Within monitoring networks, knowledge about the reliability of the instruments is more and more necessary because of the increase in complexity of the measurement systems. The quality of collected data, the frequency of breakdowns and the survival of the instruments are all greatly dependent on the environmental conditions under which those devices operate; the conditions can reach extreme levels and can be demanding for both electronic and mechanical parts. In this paper the effects of the operational environment on the instruments used for "in-situ" measurements, are analysed.