RADIOMETER ABL800 FLEX Reference Manual

ABL800 FLEX Reference Manual 2. Amperometric measuring principles
pO
2
electrode, Continued
The Ag
+
ions are released into the electrolyte solution where they react with the
Cl
−
ions present, producing AgCl which is insoluble and forms a layer on the silver
rod:
Description
(continued)
Ag
+
+ Cl
−
→ AgCl
Not all Ag+ ions can be removed from the solution. Some reach the cathode where
they are converted back to Ag and form a deposit of silver. This deposit must be
periodically removed with the brush provided in the electrode box.
Designations
The following designations are used to describe sensitivity, zero point and drift:
I(O
2
,gas1)
= Current recorded at the pO
2
electrode from a measurement on
Gas 1
I(O
2
,gas2)
= Current recorded at the pO
2
electrode from a measurement on
Gas 2
pO
2
(gas1)
= Partial pressure of O
2
in Gas 1
pO
2
(gas2)
= Partial pressure of O
2
in Gas 2
FO
2
(gas1) = Fraction of O
2
in Gas 1
FO
2
(gas2) = Fraction of O
2
in Gas 2
B
= Ambient pressure
pHO
2
= Water vapor pressure =6.2571 kPa at 37
o
C.
Sens(pO
2
,
prev)
= Sensitivity of the pO
2
electrode measured at the previous 2-
point calibration
I(O
2
,gas2,
prev)
= Current recorded at the pO
2
electrode from the previous
measurement on Gas 2
The pO
2
electrode is calibrated on two gases with known O
2
content.
Sensitivity
Gas 1 contains 19.76 % O
2
and Gas 2 contains 0.0 % O
2
.
The exact composition of the calibration gases is contained in their bar codes.
The sensitivity of the pO
2
electrode, Sens(pO
2
), is calculated as follows:
pA/kPa
(gas2)O(gas1)O
gas2),I(Ogas1),I(O
)OSens(
2 2
22
2
pp
p
−
−
=
Continued on next page
2-5

RADIOMETER ABL800 FLEX Specifications

General

Brand	RADIOMETER
Model	ABL800 FLEX
Category	Measuring Instruments
Language	English