Turbidity sensor with improved flow path

Abstract

Systems and methods for increasing the accuracy of a turbidity sensor are disclosed. The systems include a turbidity sensor and a flow module with a specialized flow path, with the turbidity sensor engaging with the flow module such that a measurement zone of the turbidity sensor is disposed within a flow path of the flow module and a bypass path of the flow module does not pass through the measurement zone. The methods include flowing a fluid containing bubbles into a system that separates the fluid in the flow module into a first stream of fluid containing relatively more bubbles and a second stream of fluid containing relatively fewer bubbles, the first stream flowing through a bypass path that does not pass through the measurement zone, and the second stream flowing through the measurement zone of the turbidity sensor.

1 . A system for measuring the turbidity of a fluid, the system comprising:
 a turbidity sensor having a light source and a measurement zone; and   a flow module having a top end, a bottom end opposite the top end thereof, an inlet, and an outlet, the inlet and outlet defining a flow path therebetween;   wherein the turbidity sensor engages with the flow module such that the measurement zone of the turbidity sensor is disposed within the flow path of the flow module.   
     
     
         2 . The system of  claim 1 , wherein the inlet of the flow module is located along a first side thereof and the outlet is located along a second side thereof, the first side located opposite the second side. 
     
     
         3 . The system of  claim 1 , wherein both the inlet and the outlet of the flow module are located along the second end thereof. 
     
     
         4 . The system of  claim 1 , wherein the turbidity sensor extends into the flow path through an opening in the flow module. 
     
     
         5 . The system of  claim 4 , wherein the opening in the flow module extends from the top end into the flow path. 
     
     
         6 . The system of  claim 4 , wherein the opening in the flow module is located on a first side of the flow module, and the inlet and the outlet are located on a second side of the flow module opposite the first side of the flow module. 
     
     
         7 . The system of  claim 1 , wherein the inlet of the flow module is located below the measurement zone of the turbidity sensor, and the outlet of the flow module is located above the measurement zone of the turbidity sensor. 
     
     
         8 . The system of  claim 1 , wherein the inlet of the flow module is located closer to the bottom end of the flow module than the outlet thereof. 
     
     
         9 . The system of  claim 1 , wherein the turbidity sensor is an optical turbidity sensor selected from the group consisting of a single beam turbidity sensor, a ratio beam turbidity sensor, a modulated four beam turbidity sensor, a surface scatter turbidity sensor, and a transmittance turbidity sensor. 
     
     
         10 . The system of  claim 1 , having a plurality of turbidity sensors, each turbidity sensor extending into the flow module through a corresponding opening in the flow module. 
     
     
         11 . The system of  claim 10 , further comprising a plurality of compartments, each compartment having an inlet, an outlet, and an opening, wherein the number of compartments is equal to the number of turbidity sensors extending into the flow module. 
     
     
         12 . The system of  claim 1 , wherein the flow module includes a bypass path that does not pass through the measurement zone. 
     
     
         13 . The system of  claim 12 , wherein the bypass path runs between an inner wall of the flow module and an outer sidewall of the turbidity sensor, above and around the measurement zone. 
     
     
         14 . A method for increasing the accuracy of a turbidity sensor, the method comprising:
 flowing a fluid containing bubbles into a system, the system comprising:
 a turbidity sensor having a light source and a measurement zone; and 
 a flow module having a top end, a bottom end opposite the top end thereof, an inlet, and an outlet, the inlet and outlet defining a flow path therebetween; 
   placing the turbidity sensor in engagement with the flow module such that the measurement zone of the turbidity sensor is disposed within the flow path of the flow module; and   measuring the turbidity of the fluid as the fluid flows through the measurement zone of the turbidity sensor.   
     
     
         15 . The method of  claim 14 , further comprising separating the fluid in the flow module into a first stream of fluid containing relatively more bubbles and a second stream of fluid containing relatively fewer bubbles, the first stream flowing through a bypass path that does not pass through the measurement zone to the outlet, and the second stream flowing through the measurement zone of the turbidity sensor to be measured. 
     
     
         16 . The method of  claim 15 , wherein the bypass path runs between an inner wall of the flow module and an outer sidewall of the turbidity sensor, above and around the measurement zone. 
     
     
         17 . The method of  claim 14 , wherein the inlet of the flow module is located along a first side thereof, and the outlet is located along a second side thereof, the first side located opposite the second side. 
     
     
         18 . The method of  claim 14 , wherein both the inlet and the outlet of the flow module are located along the second end thereof. 
     
     
         19 . The method of  claim 14 , wherein the inlet of the flow module is located below the measurement zone of the turbidity sensor and the outlet of the flow module is located above the measurement zone of the turbidity sensor. 
     
     
         20 . The method of  claim 14 , wherein the inlet of the flow module is located closer to the bottom end of the flow module than the outlet. 
     
     
         21 . The method of  claim 14 , wherein the turbidity sensor is an optical turbidity sensor selected from the group consisting of a single beam turbidity sensor, a ratio beam turbidity sensor, a modulated four beam turbidity sensor, a surface scatter turbidity sensor, and a transmittance turbidity sensor. 
     
     
         22 . The method of  claim 14 , wherein the fluid contains cells or cell debris, and is processed in a cell bioreactor before being flowed into the system.