In order to measure UV intensity from the a UV Lamp output a sensor is required to be installed on the UV Chamber for access to the water. The SC320-DWS22 system does not have the option to add a sensor to the UV Chamber. There is no available retrofit kit from the manufacturer for this system. You would have to replace the installed UV system with one that has the sensor option. Please contact us if you have any additional questions at 1-877-432-4117.