Abstract: A lamp connector assembly for an ultraviolet (UV) water treatment vessel includes a sealing collar configured to connect to a headplate of the UV treatment vessel. The sealing collar includes a first lamp collar interlock feature. A lamp collar is configured to releasably connect to the sealing collar. A release member is moveably connected to the lamp collar. The release member has a locked configuration that engages the first lamp interlock feature to prevent movement of the lamp collar relative to the sealing collar and an unlocked configuration that disengages the first lamp interlock feature to allow movement of the lamp collar relative to the sealing collar.

Abstract: A diagnostic apparatus includes a measurement head, a translating calibration element, and a calibration element actuator. The measurement head includes a diagnostic light source, a light sensor, and a measurement head body. The diagnostic light source operates at a diagnostic wavelength ?D and the measurement head body supports the diagnostic light source and the light sensor in a spaced apart relationship across a target fluid passageway to define a diagnostic light path extending from the diagnostic light source to the light sensor. The translating calibration element is partially transparent to light at the diagnostic wavelength ?D and the calibration element actuator is structurally configured to move the translating calibration element into and out of the target fluid passageway. A size and geometry of the translating calibration element is such that the translating calibration element occupies a substantial entirety of the diagnostic light path when moved into the target fluid passageway.

Abstract: A diagnostic apparatus includes a measurement head, a translating calibration element, and a calibration element actuator. The measurement head includes a diagnostic light source, a light sensor, and a measurement head body. The diagnostic light source operates at a diagnostic wavelength ?D and the measurement head body supports the diagnostic light source and the light sensor in a spaced apart relationship across a target fluid passageway to define a diagnostic light path extending from the diagnostic light source to the light sensor. The translating calibration element is partially transparent to light at the diagnostic wavelength ?D and the calibration element actuator is structurally configured to move the translating calibration element into and out of the target fluid passageway. A size and geometry of the translating calibration element is such that the translating calibration element occupies a substantial entirety of the diagnostic light path when moved into the target fluid passageway.