67
M TEMPERATURE INPUT
M TARGET TEMP
M Z FACTOR
M START SOURCE
M END SOURCE
SOURCE
DECPT
M TARGET TEMP
M Z FACTOR
DECPT
BLOCK TO CONFIGURE
M
6
CONFIGURATION – ADVANCED LEVEL…
Temperature Input Source
Select the input source (A1 to A6, B1 to B6 or Math Block M1 to M4) to perform
Fvalue calculation on.
The input sources available depend on the input options fitted – see Section 4.2.
Target Temperature
Enter the target sterilization temperature in
C.
Universally accepted standards:
Steam (Fo)
– 121.1
C
Dry Heat (Fh) – 170
C
Target Temperature Decimal Point
Set the number of decimal places for the target temperature (0 to 3 places).
Z Factor
Enter the Z factor in
C.
The change in sterilization temperature which causes factor-of-10 change in the
death rate is unique to each organism and is called the Z Factor.
Z Factor Decimal Point
Set the number of decimal places for the Z Factor (0 to 3 places).
Start Source
Select the digital source to start or reset the Fvalue calculation.
Example
– Set the high process alarm to start the Fvalue calculation when the
measured temperature reaches 100
C.
End Source
Select the digital source to end the Fvalue calculation.
Example
– Set the high process alarm to end the Fvalue calculation when the
math result reaches 10 Fvalue units.
Return to
Block to Configure
frame.
…6.2.5
Fvalue
An Fvalue calculation has to be calculated for each measuring thermocouple or RTD. The instrument can perform up to four
independent Fvalue calculations.
The input channels should be configured with a zero based range and have a sufficiently large span reading so that they do not go
over range during the purging cycle. Over-range inputs can cause a math block error and result in the Fvalue calculation being invalid.
If the sensors being used are inaccurate, the individual channels can be adjusted using the instrument’s Scale Adjust Facility – see
Section 5.1.3.