276
5 – Applications
Figure 112 – Diffusion-limited
current as a function of oxygen
molar fraction x O 2 for a total
pressure of 1.33 # 10
−3
bar.
The equation for the diffusion-limited current is
I
133.4 x
[ A]
O 2 μ
=
,
#
b. The preceding results show that we are dealing with a normal-diffusion
regime when the total pressure and temperature is 1 bar at 400 °C and with
a regime of Knudsen diffusion when the total pressure is 1.33 # 10
−3
bar
at 400 °C.
5. a. Figure 113 shows the curve for the limiting current as a function of
temperature.
Figure 113 – Limiting current
as a function of temperature
for an oxygen molar fraction
of 0.9 at 1 bar.
b. The equation for the diffusion-limited current is
I
1.02 T 563.5 [ A]
μ
=
+
,
The temperature T is expressed in °C.
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