Disposable, pre-calibrated, pre-validated sensors for use in bio-processing applications
View Patent ↗Disposable, pre-sterilized, and pre-calibrated, pre-validated conductivity sensors are provided. These sensors are designed to store sensor-specific information, such as calibration and production information, in a non-volatile memory chip on the sensor. The sensors are calibrated using 0.100 molar potassium chloride (KCl) solutions at 25 degrees Celsius. These sensors may be utilize with in-line systems, closed fluid circuits, bioprocessing systems, or systems which require an aseptic environment while avoiding or reducing cleaning procedures and quality assurance variances.
1. A method of measuring the electrical conductivity of a bio-processing fluid, comprising:
providing a particular pre-sterilized disposable electrical conductivity sensor assembly having a sensor component, a memory component and a conduit for directing a bio-processing fluid for electrical interaction with the bio-processing fluid flowing through the conduit;
running a bio-processing fluid through the conduit of the particular electrical conductivity sensor assembly;
passing a current through the particular electrical conductivity sensor component during said running of the bio-processing fluid through the conduit and measuring a resulting change in an electrical value across the sensor component, said change in electrical value being indicative of a measured electrical conductivity value of the bio-processing fluid;
retrieving a sensor-specific constant stored on the memory component of the particular electrical conductivity sensor assembly; and
calculating the actual electrical conductivity of the bio-processing fluid, said calculating comprising mathematically combining the measured electrical conductivity value with said stored constant.
2. The method according to claim 1 , further including accounting for fluid temperature variance, comprising:
measuring the temperature value of the bio-processing fluid running through the conduit for measuring its electrical conductivity;
retrieving a temperature offset stored on the memory component of the electrical conductivity sensor assembly; and
calculating the actual temperature of the bio-processing fluid, said calculating comprising mathematically combining the measured temperature value with said temperature offset.
3. The method according to claim 2 , wherein said calculating of the actual electrical conductivity value comprises mathematically combining said calculated actual temperature with said measured electrical conductivity value and with said constant.
4. The method according to claim 1 , wherein said mathematically combining includes multiplying the measured electrical conductivity value by said constant.
5. The method according to claim 2 , wherein said mathematically combining includes dividing the measured electrical conductivity value by said constant.
6. The method according to claim 1 , wherein said providing a memory component comprises providing a non-volatile memory chip.
7. The method according to claim 1 , wherein said providing a memory component comprises providing a non-volatile memory chip that is an EEPROM.