The Medway 2 Residual Analyser is used to indicate the amount of residual chlorine in water. It is installed downstream of a dosing system and by utilisation of the retransmission signal can be used to monitor or control the dosing equipment. It is designed to control the potential event of either dangerous under dosing or wasteful overdosing of chlorine. The monitor is equipped with four manually adjustable alarms and one equipment failure alarm.