A sensor system for measuring chlorine concentration in water, comprising: a manifold, comprising: a manifold inlet, in fluid communication with a fluid supply line, for receiving a manifold flow rate from a source to the manifold, a manifold outlet, in fluid communication with a fluid return line, for returning the manifold flow rate from the manifold to the source, a primary flow passage defined in the manifold and in fluid communication with the fluid supply line and the fluid return line, the primary flow passage adapted to receive a first flow rate from the manifold inlet, and a secondary flow passage defined in the manifold, the secondary flow passage adapted to receive a second flow rate from the manifold inlet, the second flow rate being substantially smaller than the first flow rate; one or more sensors (210, 220, 230) in fluid communication with the primary flow passage for measuring one or more fluid properties of the fluid flowing through the primary flow passage; and a probe for measuring chlorine concentration, the probe being positioned in fluid communication with the secondary flow passage, the probe comprising: a probe body defining a hollow portion, the probe body having a first end and a second end opposite to the first end, the hollow portion adapted to receive the second flow rate proximal to the first end, the probe body shaped and oriented to direct the second flow rate toward the second end of the probe body, and from the second end of the probe body toward the secondary flow passage, a plurality of electrodes (240, 250) positioned in the hollow portion proximal to the second end and contacting the fluid in the hollow portion, the electrodes (240, 250) adapted to generate a current in response to the concentration of chlorine present in the fluid; and wherein the primary flow passage and the secondary flow passage are oriented such that the fluid from the second end of the probe body flowing through the secondary flow passage mixes with the fluid directed toward the primary flow passage. a manifold inlet, in fluid communication with a fluid supply line, for receiving a manifold flow rate from a source to the manifold, a manifold outlet, in fluid communication with a fluid return line, for returning the manifold flow rate from the manifold to the source, a primary flow passage defined in the manifold and in fluid communication with the fluid supply line and the fluid return line, the primary flow passage adapted to receive a first flow rate from the manifold inlet, and a secondary flow passage defined in the manifold, the secondary flow passage adapted to receive a second flow rate from the manifold inlet, the second flow rate being substantially smaller than the first flow rate; one or more sensors (210, 220, 230) in fluid communication with the primary flow passage for measuring one or more fluid properties of the fluid flowing through the primary flow passage; and a probe for measuring chlorine concentration, the probe being positioned in fluid communication with the secondary flow passage, the probe comprising: a probe body defining a hollow portion, the probe body having a first end and a second end opposite to the first end, the hollow portion adapted to receive the second flow rate proximal to the first end, the probe body shaped and oriented to direct the second flow rate toward the second end of the probe body, and from the second end of the probe body toward the secondary flow passage, a plurality of electrodes (240, 250) positioned in the hollow portion proximal to the second end and contacting the fluid in the hollow portion, the electrodes (240, 250) adapted to generate a current in response to the concentration of chlorine present in the fluid; and wherein the primary flow passage and the secondary flow passage are oriented such that the fluid from the second end of the probe body flowing through the secondary flow passage mixes with the fluid directed toward the primary flow passage. a probe body defining a hollow portion, the probe body having a first end and a second end opposite to the first end, the hollow portion adapted to receive the second flow rate proximal to the first end, the probe body shaped and oriented to direct the second flow rate toward the second end of the probe body, and from the second end of the probe body toward the secondary flow passage, a plurality of electrodes (240, 250) positioned in the hollow portion proximal to the second end and contacting the fluid in the hollow portion, the electrodes (240, 250) adapted to generate a current in response to the concentration of chlorine present in the fluid; and wherein the primary flow passage and the secondary flow passage are oriented such that the fluid from the second end of the probe body flowing through the secondary flow passage mixes with the fluid directed toward the primary flow passage.