F-value Computation for the Sterilization Process for Pharmaceutical and Chemical Products

Overview

When sterilizing preserved foods by heating, bacteria must be completely annihilated without changing the heat of the product (a degradation of the taste) and the integrated fatality (F value) must be recorded and monitored. By using the computation function of the SMARTDAC+ series Paperless recorder GX/GP (relational computation, four arithmetical operations, and exponential computation), the F value can be calculated and recorded.

Advantages

• The F value at a specified sterilization temperature is automatically computed and recorded as production data.
• Using external input contact, recording can be started or stopped automatically.
• Automatic data file transfer and WEB monitoring are available.

F value

“F value” is The integrated fatality of the bacteria obtained by heat sterilization.  It is the integrated value of the fatality rate (Li) of the bacteria per unit amount of time (Δt),  and Li is a function of the sterilization temperature.

 

Configuration Example on the SMARTDAC+

Ex. Sterilization temp. Tr=121.1degC, Z value Z＝10degC,
      Measurement interval Δt=0.0167min(=1sec)

• Constant
  K1=10, K02=10.0degC(Z value), K03=121.1degC(Sterilization temp.), K04=0.0167min(measurement Interval), K05=100degC(measurement interval)
• Constant K2 to K5 may vary depending on the conditions.
• Equations
  Measurement channel 0001
  MATH channel A001：　K01**((0001-K03)/K02) ←Li value
  MATH channel A002：（A002+A001*K04)*(0001.GT.K05) ←F value

*When the temperature falls to 100℃, the value of A002 is reset to 0.