Thank you for your comment. It is a good clarification on the difference between ‘no maintenance’ and ‘failure’. The Optimus™ OPT100 DGA monitor is designed so that it does not need any maintenance actions by user to maintain its measurement performance. However, with modern electronics, it is possible, although unlikely that a component fails, for example. This has been considered in OPT100 development by implementing self-diagnostics procedures which continuously monitor its critical components and operational functions informing the user if any issue arise.
And like you said, obviously the quality of the on-site installation is an important factor as well for reliable long-term online monitoring.