HA243821
Issue 5 Mar 98
Section5
Page 5 - 19
MODEL 346 INSTALLATION AND OPERATION MANUAL
5.6.2 MATHS FUNCTIONS (Cont.)
F value
F Value (Sterilization Constant)
where:
Fo
t
= Current Fvalue
Fo
t-1
= Last time’s F value
Input 1 = input temperature
Input 2 = sterilising temperature
Input 3 = 'z’ value.
The constant 0.00839166 is a minutes/sample factor, derived by dividing the sample time of 503.5 msec. by 60
Fo reset sets the Fo
t-1
term to zero.
Should Input 3 (z value) ever be zero, the output limits at 99999.
RH Relative Humidity.
The % relative humidity equation requires the following inputs:
Input 1 = wet bulb temperature (in ˚C)
Input 2 = dry bulb temperature (in ˚C)
Input 3 = atmospheric pressure (in BAR)
Input 4 = psychrometric constant (6.660 x 10
-4
)
ZRO2Sensor
ZrO
2
Sensor - Zirconia Oxygen Probe.
The output is the partial pressure of oxygen
where:
Input 1 = partial pressure at electrode in %
Input 2 = probe emf in mV
Input 3 = Probe temperature in degrees Rankine (Fahr 460)
Fo
t
=
Fo
t
−
1
+
0.00839166
×
10
Input1
−
Input2
Input3
Output =
Input 1
10
B
B =
Input 2
0.0496
×
Input 3