Certain embodiments include a sensor system for measuring chlorine concentration in water. The sensor system can have a manifold including one or more flow passages for receiving fluid flow. The sensor system can have a probe for measuring chlorine concentration in fluid communication with a flow passage of the one or more flow passages of the manifold. The probe can have a probe body oriented to direct incoming fluid from one or more flow passages of the manifold toward an end of the probe body. The probe can have a plurality of flutes defined on an outer surface of the probe body. The flutes can be shaped and oriented to direct fluid from the end proximal to the electrodes, back toward the one or more flow passages of the manifold.