Rapidlab 1200 Operator’s Guide: System Overview and Intended Use
1-39
02087462 Rev. V
pO
2
Sensor
The
p
O
2
sensor is based upon the electrode described by Clark.
11
It is a complete
electrochemical cell that incorporates amperometric technology. The sensor
consists of a platinum (Pt) cathode, and silver (Ag) anode, an electrolyte solution,
and a gas-permeable membrane.
Figure 1-32 pO
2
Sensor
A constant voltage, called a polarizing voltage, is maintained between the anode
and the cathode. As dissolved oxygen from the sample passes through the
membrane into the electrolyte solution, it is reduced at the cathode:
−
−
→
+
+
OH
e
O
H
O
4
4
2
2
2
The circuit is completed at the anode, when the Ag is oxidized:
−
+
+
→
e
Ag
Ag
4
4
The amount of reduced oxygen is directly proportional to the number of electrons
gained at the cathode. Therefore, by measuring the change in current (electron
flow) between the anode and the cathode, the amount of oxygen in the electrolyte
solution is determined.
9
1
Cathode contact
2
Anode contact
3
Sample path
Summary of Contents for Rapidlab 1200
Page 1: ...Rapidlab 1200 Systems Operator s Guide 02087462 Rev V 2010 01 ...
Page 6: ...iv Rapidlab 1200 Operator s Guide Using This Guide 02087462 Rev V ...
Page 88: ...1 68 Rapidlab 1200 Operator s Guide System Overview and Intended Use 02087462 Rev V ...
Page 126: ...2 38 Rapidlab 1200 Operator s Guide Operating the System 02087462 Rev V ...
Page 206: ...5 64 Rapidlab 1200 Operator s Guide Maintenance 02087462 Rev V ...
Page 290: ...6 84 Rapidlab 1200 Operator s Guide Troubleshooting 02087462 Rev V ...
Page 344: ...A 4 Rapidlab 1200 Operator s Guide Safety Instructions 02087462 Rev V ...
Page 354: ...B 10 Rapidlab 1200 Operator s Guide Service Ordering and Warranty 02087462 Rev V ...
Page 360: ...D 4 Rapidlab 1200 Operator s Guide Supplies 02087462 Rev V ...
Page 448: ...I 8 Rapidlab 1200 Operator s Guide Index 02087462 Rev V ...