MONITORING APPARATUS

摘要

This invention relates to monitoring apparatus and, in particular, but not exclusively to such apparatus for use in association with main water supply facilities. A water work (10) has a water main (12), in which is located a filtration unit (13) having a filter (17). A pressure transducer (17a) monitors the pressure drop across the filter (17) to initiate backwash. The conditions of backwash are monitored by a control unit (20) which operates valves (21 to 24) so that when abnormal conditions are detected a sample of the backwash fluid can be captured in reservoirs (25 to 27) in accordance with the degree of abnormality.