Determination Of Co Concentration; Measurement Cycles With The Inpro 5500 I - Mettler Toledo InPro 5500i Instructions D'utilisation

10
3.2.2 Determination of CO
The rise factor (RAMP) the diffusing gas creates
on the TC-chip (resulting voltage) is proportional to
the partial pressure of the CO
p(CO
Using its integrated temperature sensor, the
I nPro 5500i directly measures the process tem-
perature for accurate temperature compensation.
The temperature compensation is needed due to
the dependancy of the CO
selective membrane.
The measured partial pressure of CO
cess temperature allow the exact calculation of CO
concentration (g/L) using Henry's law.
Henry's Law:
At a constant temperature, the amount of a given
gas that dissolves in a given type and volume of
liquid is directly proportional to the partial pressure
of that gas in equilibrium with that liquid.
c(CO
p(CO
c(CO
H = Henry's constant

3.2.3 Measurement cycles with the InPro 5500 i

Purge cycle (app. 10 sec)
The purge gas flushes the measuring chamber until
a flat base line is determined by the TC-Chip.
CO measuring cycle (app. 10 sec)
2
The diffusing CO
(thermal conductivity) and the digital sensor calcu-
lates the CO
The calculated value is sent digitally to the con-
nected transmitter.
h
ISM sensor:
The InPro 5500 i is equipped with Intelligent Sensor
Management (ISM).
Principle: The sensor head contains a microproces-
sor that monitors and controls the sensor and also
stores all sensor data. The data is accessed via the
transmitter.
InPro 5500 i
30 035 328
).
2
) = p(CO ) * H
2 2
) = partial pressure CO
2
) = concentration CO
2
2
concentration.
2
concentration
2
2
permeability of the gas
2
2
(g / L)
2
increases the measured voltage
© 06 /14 Mettler-Toledo AG
InPro 5500 i CO
in the process liquid
and the pro-
2
Printed in Switzerland
Sensor
2
2