Roche cobas b 123 User Manual

Roche Diagnostics
Instructions for Use · Version 13.0 43
cobas b 123 POC system 2 General description
Consumable information
BG sensors
BG sensors measure pH, PO
2
, PCO
2
and Hct parameters.
Figure 2-20 BG sensor
PO
2
sensor Uses the Clark measurement principle. Oxygen is diffused through a membrane to a
gold multi-wire system with negative electric potential inside of the sensor. Oxygen is
reduced here, which generates an electric current that is proportional to the amount
of oxygen in the sample. This measurement is amperometric.
PCO
2
sensor Uses the Severinghouse principle. CO
2
diffuses through a membrane similar to the
PO
2
sensor. In the sensor, change in CO
2
concentration affects the pH. This
measurement is potentiometric.
pH sensor The pH sensor consists of a pH-sensitive membrane. Depending on the pH value of
the sample, electric potential is generated at the boundary layer between the
membrane and the sample. This potential can be measured potentiometrically by a
second sensor, the reference sensor (in the ISE sensor part).
A Conductivity contact E CO
2
measuring contact
B O
2
measuring contact F pH sensor (BG)
C O
2
reference contact G Conductivity contact
D CO
2
reference contact
E
F
C
D
A
B
G

Roche cobas b 123 Specifications

General

Brand	Roche
Model	cobas b 123
Category	Medical Equipment
Language	English