Any factor (water, mud etc.) that could dirty the internal part of the “SUS” optical sensor unit’s cover can influence the TEL-310S correct functioning. So it is essential to protect properly the “SUS” optical sensor unit from weather conditions, leaving anyway the access possibility for cleaning/maintenance.
In any case, TEL-310S has an auto-diagnostics able to alert the user for the maintenance. Sample solution used to protect the instrument (old TEL-310) from weather conditions.