Flow monitors for disinfection variables Membrane-covered sensors for water disinfection (e.g. free chlorine or total chlorine, ozone, chlorine dioxide, etc.) must be operated with a minimum flow rate of 15 cm/s. The flow monitor is integrated into the sample water supply line, in series with the disinfection sensor, and monitors the required minimum flow to the sensor. Below the minimum flow velocity, the sensors measure values that are too low. This can cause a connected control system to dangerously overdose or underdose. Above the minimum incident flow velocity, the measuring signal is only slightly influenced by the incident flow velocity. The flow monitor consists of a flow body, a needle valve insert for flow regulation and an inductive proximity switch, which is controlled by a float in the medium flow. When the minimum flow velocity is reached or exceeded, the float rises and the contact of the inductive proximity switch switches. The contact can be used, for example, to control a binary input of the controller for standard signals, JUMO AQUIS 500 AS. If the flow is too low, the controller is set to the ‘HOLD’ state. This prevents incorrect dosing.   Areas of application Flow monitoring when using sensors for free chlorine, chlorine dioxide, ozone, hydrogen peroxide or peracetic acid