XTP501 & XTC501 User’s Manual
2
99976 Issue 1.1, May 2020
INTRODUCTION
1.1
Sensor Technologies
1.1.1 Thermo-paramagnetic
Michell’s thermo-paramagnetic sensor uses a combination of paramagnetic and thermal
conductivity techniques to accurately measure the oxygen content within a process gas.
Oxygen is a paramagnetic gas, which means that it is attracted to a magnetic field. It
is this property that can be exploited to help determine the level of oxygen in many
background gases. The magnetic susceptibility of oxygen changes with its temperature,
so Michell’s thermo-paramagnetic analyzer uses a temperature-controlled measuring
chamber. The sensing element is in a diffusion chamber out of the direct flow of gas
to ensure a stable measurement that also offers mechanical protection to the sensor.
Advantages of Thermo-Paramagnetic:
•
The thermo-paramagnetic sensor has no consumable or moving parts
which means lower cost of ownership
•
Units are calibrated specifically to maximize the accuracy at the required
measurement range
•
Stable measurements
•
Good balance of price and performance