|
1
SPECIFICATIONS
|
TB2 series sensor model
and specifications |
| Model |
TB2A |
TB2B |
| Application
Occasion |
Smoke
or else |
Microanalysis
or High Content Analysis |
| Scale |
-5%
O2~25%O2 |
1ppm
~100%O2 |
| Accuracy |
Less
than ±2%FS |
Less
than ±2%FS |
| Repeatability |
Less
than±1%FS |
Less
than±1%FS |
| Stability |
Less
than±2%FS/M |
Less
than±2%FS/M |
| Response |
Less
than 5s |
Less
than 10s |
| |
(90%response) |
(90%response) |
| Sample
Temp. |
≤1600℃ |
≤1600℃ |
| Sample
Pressure |
10-3
Torr - 0.2MPa |
| Ambient
Temp |
-40~100℃ |
| Warm
Up Time |
About
10min |
| Heat
Power |
Normal
10VA |
2
PRINCIPLE
2.1
Sensing Cell
Sensing
cell is a closed end,90mm
length and 7.0mm
diameter tube made of Zirconium
oxide. When it is red hot, it becomes
a oxygen concentration cell because
of movement of oxygen ions in its
crystal structure. If there are
two different gases having different
oxygen partial pressure on both
side of the cell, a voltage is produce.
Electrodes
of porous platinum are coated onto
inside an outside of the cell and
connected to a panel meter circuit.
Outside(sample side)of the cell
is coated with ceramic filter.
2.2
Oxygen Analysis
When
both side of the cell contact with
gases which have different oxygen
partial pressure, a voltage (EMF)
is produced that is logarithmic
proportional to the ratio of oxygen
concentration of the cell is known
(usually ambient air ---20.95%c),
another side i.e. the sample oxygen
can be directly measured by cell
EMF.
The
cell EMF is also related to cell
temperature. Therefore the cell
is maintained at constant temperature
using (RTD), proportional temperature
controller and electrical cell heater.
For
the oxygen in non-combustible gases,
the oxygen value is calculated from
following formula:
E=0.0496.
T. log(20.95%/x%)+C
Where
T is the absolute cell temperature
and O2
x% is vol % of oxygen
of the sample gas. The sensing cell
therefore, produce no signal when
air is on both side, and the voltage
increases is the sample oxygen content
becomes more different from air.
Under
the vacuum condition, oxygen partial
pressure relates to vacuum. For
example, 760ppm at atmospheric pressure
becomes 1ppm at 1Torr vacuum.
3
OPERATION
3.1
Start up
1)
Turn on the power
supply of Control unit.
2)
About 10 minutes
after, when the display of control
unit will show (CELL TEMP) 735℃, sensor should
be in operating condition.
3.2
Stop
Cut
of the supply of Control Unit.
4
CALIBRATION
l
Condition of Calibration
Gas
1)
Generally, instrument
air (20.95% O2 ) or ambient
air is used for span gas.
2)
100~200ppm% O2
is N2 mixture is
used an zero gas.
l
Periodical calibration
During
operating, we recommend calibration
gas check 1time per 2 or 3 moths.
When analyzer works unusually, gas
check also recommended.
|
