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ONH-2000
Oxygen
/ Nitrogen / Hydrogen Determinator |
 Oxygen/Nitrogen
model
ON-900
Oxygen/Hydrogen
model
OH-900
Hidrogen
model
H-500 |
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| Overview |
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The ONH-2000 is designed for the rapid and accurate
determination of oxygen, nitrogen and hydrogen in copper,
steel, cast iron, alloys, zirconium, titanium, molybdenum,
nickel, ceramics and other inorganic materials. The
ONH-2000 can be supplied with two independent infrared
cells to provide optimum precision for the analysis
of high and low levels of oxygen. Nitrogen and hydrogen
are detected with a dual range thermal conductivity
cell. The change over from the low to the high ranges
is done automatically during the analysis and does not
require any pre-setting by the operator. The ONH-2000
features a 16-bit microprocessor and solid state infrared
detectors with auto zero and auto range control. The
water cooled high power electrode impulse furnace uses
a graphite crucible to heat the sample up to a temperature
of 3000° C.
On request the ONH-2000 measuring ranges can be optimized
in the factory to suit your requirements, without additional
charges. The sensitivity of the detectors can be designed
to provide maximum accuracy in ranges from low ppm up
to high percentage concentrations.
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| Analysis
procedure |
The sample is weighed on an electronic balance which is interfaced
to the PC. By pushing a button the sample weight is transferred
into the PC. If required the sample weight can also be entered
manually. The sample is placed into the loading head and the
graphite crucible is put on the lower electrode tip. The start
key is pressed and the analysis cycle runs automatically.
The furnace closes, the crucible is outgased, the sample is
dropped into the crucible and the analysis proceeds. At the
end of the cycle, the analysis results appear on the built
in display and are transferred to the connected PC. A manual
loading of the sample is also possible. The manual loading
is necessary for the analysis of powders. |
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| PC
control with Windows 2000/XP software |
Comprehensive
analyser control and easy operation are provided by
the software running on PC, connected to the analyser.
Click software
from the main menu for more information about software.
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| Fractional
analysis |
Every
oxide has a characteristic decomposition temperature.
The furnace power can be raised slowly until a particular
oxide breaks its bond. Continually increasing the temperature
will separate various oxides.
For this purpose the software can control the furance
power, either by ramping or in steps up to a maximum
of 3000° C. The peaks are individually integrated
by the software and the individual values of the different
oxides are displayed. |
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| Applications
memory |
The
settings for different applications can be stored in memory
and they can be recalled for later analysis of the corresponding
material. Due to this feature, the operator does not need
to enter new settings every time he has to analyze a sample
of a material different to that of the sample before. Also
every time new settings are found for a new kind of samples,
the operator can memorize them in the PC software. This facility
is practically a must, especially for fractional analysis. |
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| Infrared
Cells |
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The
infrared cells of the OH-900 do not require any manual
zero adjustments. The zero and sensitivity adjustments
of the infrared cells are permanently and automatically
controlled by the electronics. The detectors utilize
solid state sensors combined with infrared filters.
The sensors are not gas filled, thus eliminating long
term problems due to gas leakage. The OH-900 can be
equipped with up to two independent infrared cells for
oxygen determination. The lengths of both cells can
be individually optimized, to obtain maximum precision
for the target analysis levels of each customer. Each
of the cells can be installed with infrared absorption
lengths ranging between 1mm and 320mm. |
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| Thermal
conductivity cell |
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Hydrogen concentrations are determined by a thermal
conductivity detector. This detector was especially
developed by ELTRA in order to guarantee low drift,
high resolution and wide measuring ranges. |
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| Upper
electrode insert |
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The furnace of the OH-900 features an upper electrode
insert. It can be easily and quickly replaced by the
operator. It is therefore a very economic solution when
the upper contact surface to the crucible is worn out. |
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| Grain
and drillings analysis without tin capsule |
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The design of the sample drop mechanism enables the
analysis of grains and drillings without the risk of
blockages. Therefore the grains can be put into the
furnace without the need of a tin or nickel capsule.
The elimination of the need for a capsule has the following
advantages:
· No blank values of the capsule
material.
· No blank values due to the air
enclosed in the capsule.
· No contamination of the furnace
and of the gas flow system due to evaporation of the
capsule material when analyzing with high power, especially
for nitrogen compounds requiring high temperature.
· No costs and delays for maintenance
due to the capsule evaporation.
· No costs and delays due to the
time required to tare and handling of the capsule and
to put the grains into it.
· No expenses for capsules. |
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| Graphite
tip |
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The
crucible is placed on a graphite tip. Due to the electrical
resistance of the graphite, there is a power dissipation
in it, so that the graphite tip heats up the bottom
of the crucible. This effect moves the hot zone from
the middle of the crucible down to the bottom where
the sample is.
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| Hot
extraction analysis |
The OH-900 can determine the residual hydrogen in the sample,
by heating up the sample at a temperature below the melting
point. This can be obtained by setting the power at a relatively
low level (about 1.2 kW). In order to be able to analyse big
samples, a bigger crucible is used in this case. The big sample
is put directly into the crucible by the operator, using the
manual loading mode of the analyzer. |
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| Saving
carrier gas |
When the OH-900 is in analysis mode, but it has not been used
for a while, the gas consumption will automatically be reduced
to a very low level. This low flow keeps the gasflow system
flooded with carrier gas, preventing the air from penetrating
the system.
As soon as the operator starts using the analyzer again, the
normal flow will be automatically restored. The analyzer will
be again ready for operation in a very short time, due to
the purging with the low flow during the break. |
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| Cooling
system |
The
OH-900 has a primary and a secondary cooling system.
This is to prevent the tap water from passing through
the furnace. Tap water can contain carbonates and, depending
on the tap water quality of each location, it may contain
contaminants which can attack and damage the internal
cooling surface of the furnace. The carbonates can additionally
form a thermal insulating layer on the inner surface
of the furnace, reducing the cooling effect of the water.
The primary cooling system of the OH-900 consists of
a closed loop of clear water circulating from a tank
through the furnace, utilizing a water pump within the
OH-900.
The secondary cooling system is connected to tap water
which flows through a coil of metal tube, cooling the
water in the tank as a thermal exchanger. There is no
mixing of the tap water with the clear water of the
primary system. A thermostatic control opens the tap
water valve at a certain temperature level of the water
in the tank. The valve closes again when the water is
cooled down. The water tank is not inside, but outside
the analyzer. This configuration reduces rapidly the
risk of water problems with the analyzer in case of
leakages. The tank is made of very solid stainless steel.
It can be placed under the desk underneath the analyzer
saving space on the desk. The analyzer's size is small
due to the tank being outside the analyzer. The tank
itself is big, accommodating a big quantity of water
to ensure low variations of the water temperature during
analysis.
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| Residual
hydrogen analysis |
The
ONH-2000 can be supplied with an auxiliary tube furnace
for the analysis of residual hydrogen by hot extraction.
The furnace has a temperature range from near ambient
to 1000° C.
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| Glove
box design |
The
ONH-2000 can be supplied for glove box operation. In
this case the furnace part of the instrument is installed
inside the glove box and the remainder outside. By splitting
the instrument we minimise the amount of contaminated
material and improve access for maintenance.
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| Gas
purifier |
The
external gas purifier is used to remove residual oxygen
in inert carrier gases.
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| Compliance |
The ONH-2000 complies to the specifications of the standards:
ASTM
E-1019, E-1587, E-1409, E-1569, E-1447, E-1937
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Next:
ONH-2000 Specifications |
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