A major Biopharma company in USA now uses the Biomass Monitor 220 to establish a PID control loop for viable biomass. In addition, BioXpert software (Applikon Inc, USA) was used to digitally log biomass and to perform supervisory control.

The following simple setup was used to create the control loop for biomass:

• The 4-20 mA signal generated by the 220 instrument was acquired directly by the Applikon ADI 1030 controller.
• The ADI 1030 controller was scaled to the equivalent viable biomass expressed in cell/ml.
• PID values were modified on the 1030 instrument to optimize control performance.
• A setpoint for biomass was input to the controller. Control was configured so that a media feed pump was automatically engaged when the measured process valued exceeded the setpoint. Both time and/or event based control of the viable biomass setpoint was performed.

The same facility for data logging and process control can be established with any industry standard control system such as Allen Bradley, Delta V or Siemens. The use of fieldbus technology with these control platforms would facilitate process control for viable biomass.