In the ceramic production the thermo-element is
the hot working monitor and the test measurement tool, is playing the
vital role. In in the current each kind of ceramic product
production technical process, the examination technology and its the
apparatus are more and more important, especially in carries on to
each kind of product and the component not damages the abrasion, the
survey and the measurement aspect, the ceramic thermo-element function
has lasting achievements, regarding enhances the ceramic product the
quality and enterprise's economic efficiency is indispensable.
The thermo-element principle of work is connects two kind of
different conductors and the semiconductor the closed path, again
respectively sets at its two contacts to the temperature each is T and
in the T 0 heat sources, then then produces in this return route
热电动势, also calls 热电? this kind of phenomenon is called
the pyroelectric effect. But the thermoelectric force is in the
identical conductor beginnings and ends one kind which different
produce because of its temperature 热电? Because high
temperature end (T) the electronic energy is bigger than the low
temperature end electronic energy, thus runs from the high temperature
end to the low temperature end 电子?runs from the low temperature
end to the high temperature end must be more than, its result is the
high temperature end loses the electron but to bring the positive
charge, the low temperature end because of to obtain the electron but
to bring the negative charge, thus forms an electrostatic field.
Like this then has a corresponding potential difference in the
conductor beginnings and ends is the thermoelectric force. Like
this turns on the third kind of material in the thermo-element return
route the wire, so long as the third kind of wire beginnings and ends
temperature is same, then the third kind of wire introduction cannot
affect the thermo-element the electromotive force. The root
according to the above the nature, introduces each kind of measuring
appliance, the connecting lead in the return route and so on, Don't
worry to the thermo-element the influence, therefore also may use
焊接?makes the thermo-element. At present in the newspaper
advertisement the numeral demonstrated the thermo-element is becoming
the mainstream.
Ceramic thermo-element type. Has the platinum rhodium -
platinum thermo-element, a nichrome nickel silicon thermo-element, the
nichrome - tests type and so on copper thermo-element.
1 platinum rhodium - platinum thermo-element: Is uses the
precious rare metal material to make, (platinum 90% with rhodium 10%)
is made by the diameter 0.5 m m pure platinum wire and the same
diameter platinum rhodium silk, indicated by mark L B. Mark W R
refers to the thermo-element. In L in the B thermo-element the
platinum rhodium silk is a positive electrode, the pure platinum wire
is a cathode. This kind of thermo-element may in 1,300 ?below
Fan length of perimeter time use, be possible the short-term to survey
1,600 ?high temperatures in the good use environment. As a
result of the chemical development, is easy to obtain the high-purity
platinum and the platinum rhodium material, therefore L the B
thermo-element manufacture precision and the survey accuracy are high,
may use in the precise temperature survey with to make the datum
thermo-element use. The platinum rhodium - platinum
thermo-element is the ceramic industry fires most commonly used
measured the warm apparatus, generally may use in to construct the
sanitary earthen ware, the ceramics for daily use and the fine arts
ceramics product production. L the B thermo-element has the
higher physical chemistry stability in oxidability or in the neutral
medium. Its main insufficient lies in 热电势is weaker.
Fires in the environment in the high temperature easily to
return to original state the vapor and the metal vapor violation which
the gas sends out deteriorates. In recent years used the high
aluminum 瓷套管and the silicon carbide drive pipe changes the
thermo-element protection material quality, but effectively resisted
the noxious gas the corrosion, lengthened the service life.
Because L the B thermo-element is the expensive rare metal
material manufacture, therefore the product cost is very high, needs
to use gives devotedly illuminates protects. Its selling price
standard acts according to its length size to decide, massively uses
the advanced 窑衬 material, the kiln wall along with the new kiln
stove changes thinly, the thermo-element length also has reduces the
tendency. Usual length 30 c m ~ 60 c m L B thermo-element,
selling price between 1,200 Yuan - 5,000 Yuan.
A 2 nichromes nickel silicon thermo-element: Are made by
the nichrome and the nickel silicon, uses mark E U to indicate.
The thermo-element silk diameter generally is 1.2 ~ 2.5 m m.
The nichrome is the positive electrode, the nickel silicon is a
cathode. E the U thermo-element chemical stability is high, may
the long time surveys 900 ?below in oxidability or in the neutral
medium the temperature, the short-term survey may reach 1200 ?
If uses in the reducible medium, then can very quickly receive
the corrosion, only can use in to survey 500 ?below the
temperature. E the U thermo-element has the duplication well,
has 热电? the linearity in a big way is good, merit and so on
price small advantage. Its measuring accuracy slightly somewhat
low, but also can completely satisfy the ceramic industry survey
request. In the low temperature ceramics color fever, the low
temperature ceramics roasts the flower and the half-finished product
dry aspect in particular, may become the commonly used one kind of
thermo-element. At present, our country started by the nickel
silicon material to replace the nickel aluminum alloy material.
Uses thermo-element which the new material makes, and
热电势the stable aspect all has the very big enhancement in the
anti- oxidation, but its material quality is crisper also the welding
performance and 抗辐射 the energy balance. Because two
kind of thermo-elements thermoelectricity performance are nearly
consistent. Therefore the original nichrome - nichrome
thermo-element gradually substitutes for the nichrome - nickel silicon
thermo-element.
3 nichromes - test the copper thermo-element: By the
nichrome material and the nickel, the copper alloy material are
composed, uses mark E A to indicate. The thermo-element silk
diameter generally is 1.2 m m ~ 2 m m, the nichrome is a positive
electrode, tests the copper is a cathode. Is suitable to the
reducibility or the neutral medium, the long-term application
temperature cannot surpass 600 ? the short-term survey may reach
800 ? E the A thermo-element characteristic is the
thermoelectricity sensitivity high, price cheap, but it measured warm
scope low also narrow, tests the copper alloy silk to be easy because
to oxidize deteriorates. Hard but is not easier as a result of
the material quality of material to obtain the even line diameter.
This kind of type thermo-element may use to, ceramic heat
interchanger place and so on ceramic 坯体 drying, in order to
obtains the more precise temperature parameter, enhances dry and
effect and so on energy conservation.
4 platinum rhodiums 30 - platinum rhodiums 6 thermo-elements:
Is by platinum rhodium 30 (platinum 70%, rhodium 30%) is the
positive electrode, platinum rhodium 6 (platinum content 94%, rhodium
6%) is a cathode. It may use in to survey the high temperature
for a long time to reach 1,600 ?temperatures, the short-term may
survey 1,800 ?superelevation temperatures. L the L
thermo-element performance stable, the precision is high, is suitable
uses to oxidability and in the neutral medium. But it produces
热电势young, also the price is expensive. At present, the
special ceramic in particular high temperature structure ceramics
product fires (for example zirconium oxide ceramics, 99 aluminum
oxides ceramics) the temperature reaches as high as 1,600 ?~ 1,800
?scopes, uses L the L thermo-element is completely feasible.
Along with the special ceramic product series expansion, each
kind is suitable the ceramic thermo-element which fires to high
temperature and the superhigh temperature kiln stove can obtain a
bigger use.
The conventional thermo-element unceasingly expands while
ceramic production use, has a better function the special
thermo-element product unceasingly to be published. If the
tungsten rhenium is a thermo-element, it is one kind of better
superhigh temperature thermo-element material, its highest application
temperature the insulation material limit, generally may achieve 2,400
?exploitation conditions. If when vacuum by bare wire survey
may use a higher temperature. At present, our country production
tungsten rhenium thermo-element, it take the tungsten rhenium 5 as the
positive electrode, the tungsten rhenium 20 makes the cathode.
The use scope is 300 ?~ 2,000 ? divides a precision to be
possible to reach ± 1%. At present, on the international
certain nitrided silicon ceramics agglutinate the temperature to
achieve 1800 ?above, use the tungsten rhenium thermo-element to
carry on measured warm is completely feasible. In addition is
suitable the superconductivity ceramics production use the golden iron
- nichrome low temperature thermo-element, rapid reaction thin film
thermo-element and nonmetallic thermo-element material, because has
each kind of merit and the price inexpensive, the resources is rich,
obtains the encouraging progress.
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