EP0616691A1 - Appareillage et procede de detection de traces d'humidite dans des substances solides et liquides - Google Patents

Appareillage et procede de detection de traces d'humidite dans des substances solides et liquides

Info

Publication number
EP0616691A1
EP0616691A1 EP92924722A EP92924722A EP0616691A1 EP 0616691 A1 EP0616691 A1 EP 0616691A1 EP 92924722 A EP92924722 A EP 92924722A EP 92924722 A EP92924722 A EP 92924722A EP 0616691 A1 EP0616691 A1 EP 0616691A1
Authority
EP
European Patent Office
Prior art keywords
windings
moisture sensor
gas
cell
moisture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP92924722A
Other languages
German (de)
English (en)
Inventor
Roland Wagner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BERGHOF LABOR- und AUTOMATIONSTECHNIK GmbH
Original Assignee
BERGHOF LABOR- und AUTOMATIONSTECHNIK GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BERGHOF LABOR- und AUTOMATIONSTECHNIK GmbH filed Critical BERGHOF LABOR- und AUTOMATIONSTECHNIK GmbH
Publication of EP0616691A1 publication Critical patent/EP0616691A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/56—Investigating or analyzing materials by the use of thermal means by investigating moisture content
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/416—Systems
    • G01N27/42—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte
    • G01N27/423—Coulometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/0004—Gaseous mixtures, e.g. polluted air
    • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
    • G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
    • G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component

Definitions

  • the present invention relates to a system apparatus and a method for the determination of traces of water in solid and liquid substances, in particular water content determinations in the ppm and percentage range are carried out.
  • This apparatus works according to a method for determining traces of water in solid and liquid substances with the following method steps:
  • the carrier gas is subsequently dried in a molecular sieve to less than or equal to 3 ppm and is then fed via a changeover valve to a temperature cell which, after a certain temperature profile or a temperature program from room temperature to about 800 ° C is heated, whereby any amounts of water in the substance are converted into the vapor phase.
  • the process step for example, of splitting any hydrocarbon compounds present in a so-called pyrolysis unit, has a particularly advantageous effect, so that the hydrocarbon compounds which may have been expelled enter the water cell only in split form, which protects the water cell serves.
  • the determination of traces of water in the substance to be examined can be carried out in an impressively simple and precise manner by electrochemical means.
  • a coulombmetric sensor for the selective determination of the water content, as he, the sensor, described in the second part of the application, which emits an electrical signal to the corresponding electronic units, which ultimately is used ⁇ means of a microcomputer is evaluated and displayed on a corresponding monitor.
  • the result displayed on the monitor can also be displayed graphically by means of a further recording device, such as a plotter.
  • the system apparatus according to the invention is therefore an advantageous analytical measuring device for determining the smallest amounts of water in solid and liquid substances. Contrary to the traditional wet-technical investigation methods, the advantageous system apparatus works according to a direct method, so that an expensive sample preparation is no longer necessary.
  • the system apparatus according to the invention operates with an accuracy in a range that was previously only the wet technology The procedure remained reserved.
  • the system apparatus which is operated according to the method according to the invention, is able to reliably determine water fractions both in the ppm and in the percentage range.
  • the method according to the invention is similar to thermal analysis with a highly sensitive coulombmetric sensor for the selective determination of water content.
  • the principle of operation can be outlined in a few words so that a known amount of sample substance is heated from room temperature to a maximum of 800 ° C. by a predetermined, controlled heating.
  • the water released is transferred with the aid of a dried carrier gas into an encapsulated measuring cell, where it is determined quantitatively by means of an electrochemical reaction with a moisture sensor according to the invention.
  • the measured water content can be selectively and partially advantageously determined as surface / capillary / and chemically bound water (crystal water).
  • the system apparatus When operating the system apparatus according to the invention, it is advantageous to use a PC or laptop-like computer, with the aid of which necessary work processes are controlled in dialog between the user and the device according to the invention.
  • the system apparatus After the start of the measurement, the system apparatus carries out the measurement automatically.
  • the output of the measured values and a graphic of the measurement process is then expediently carried out on a monitor or a printer connected to it.
  • Fig. 1 is a block diagram of the system apparatus according to the invention.
  • FIG. 2 is a diagram which shows the measurement results achieved with the apparatus according to the invention.
  • the pyrolysis unit 3 downstream of the temperature cell 2, possibly expelled CH compounds are broken up, ie this unit is used to "crack" the CH compounds that may be present.
  • this pyrolysis unit 3 has a protective function with respect to the water cell 4, into which the water content to be measured is transferred and electrolytically split there and recorded with a suitable sensor.
  • the suitable sensor then emits a corresponding electrical signal, which is fed to processing electronics for further processing.
  • the metrological process flow is as follows.
  • the carrier gas flows through the two-way valve 12 into the molecular drying screen 1 and is freed of any residual water present here.
  • the achievable residual amount of water in the carrier gas is less than or equal to 3 ppm V.
  • the dried carrier gas then flows through the reusable valve 6, which is switched in the normal measuring mode in the direction of the temperature cell 2.
  • the temperature cell 2 is completely flooded by the carrier gas. It contains the substance to be tested, which is to be examined for its water content.
  • the test specimen is specifically heated from room temperature to a maximum of 800 ° C. by means of a predetermined temperature program, so that any amounts of water which may be present are driven out of the substance as water vapor.
  • the amount of water mixes with the inert gas and is conveyed into the pyrolysis unit 3 via the gas pressure.
  • any existing C-H connections which have also been separated from the test specimen, are split and fed to the water cell 4 through the multi-way valve 7.
  • the temperature cell 2 and the pyrolysis unit 3 are bridged by means of a suitable gas bypass 5, which is connected by the valves 6 and 7. This ensures that the cell is loaded beyond its capacity in the event of an excessive amount of water.
  • the two-way valves 12 and 13 have the task of preventing the ingress of moisture, which is always present in the circulating air, in the event of the device being switched off.
  • valve 12 to valve 13 The control of the analysis path from valve 12 to valve 13 is carried out electronically, i.e. each individual component is controlled by a driver unit, which in turn is controlled by a microprocessor 9 via an interface 10.
  • the temperature, valves, water cell 4, etc. are controlled by suitable electronics adapted in the device.
  • the data communication between the system apparatus according to the invention and the external computer system is carried out by a process computer with an interface card 10 (MFT + SOKA).
  • the system according to the invention constructed in this way has a sensitivity which permits a determination of 100 nanograms of water.
  • the reproducibility is less than or equal to 2%.
  • the entire display range extends from ppm to percent.
  • the measuring time can be freely selected between 10 minutes and 10 hours.
  • the maximum sample volume is 3.5 ccm.
  • the inert carrier gas can be, for example, argon (Ar) or nitrogen (N2).
  • the gas throughput ranges from 50 to 100 ccm / min., The maximum gas throughput also 200 ccm / min. can be.
  • the normal working pressure extends over 2 to 10 bar, whereby the maximum permissible working pressure should not exceed 10 bar.
  • FIG. 2 shows a graphical representation of the measurement results, such as those obtained with a polyamide sample.
  • the measurement time in minutes is plotted on the X axis, while the measured current is plotted in milliamps on the left Y axis and the temperature in degrees Celsius is plotted on the right Y axis.
  • the solid strong Line represents the time course of the measuring cycle of the water content of the sample substance.
  • the dashed curve shows the controlled target temperature and the weak solid line shows the actual temperature in a satisfactory manner.
  • the measuring time was approx. 10 minutes with a sample weight of 0.188 g.
  • the measured water content was 0.5461%.
  • the present invention further relates to a moisture sensor which works on the basis of the conductivity of an electrical resistance, i.e. when the moisture of the substance to be analyzed changes, the electrical resistance of the moisture sensor changes.
  • This moisture sensor is particularly suitable for measuring the moisture of a gas.
  • Such moisture sensors generally consist of a pair of electrodes which is applied to the surface of an insulating support. If the moisture condenses between the pair of electrodes, this is ascertained on the basis of a change in the current or the impedance.
  • This type of moisture sensor takes advantage of the property of some substances that change the electrical conductivity when moisture is absorbed. They absorb moisture from the measuring gas surrounding them until the water vapor partial pressures in the gas and in the conductivity layer are the same and release water vapor accordingly to the alloy when the moisture decreases.
  • two closely spaced, meandering, flat electrodes, which were applied to an insulating surface were mostly used for the conductivity moisture sensors. This surface was prepared with a hygroscopic electrolyte layer, the conductivity of which changes with the equilibrium moisture. This electrolyte layer was slightly irreversibly damaged by the action of too much or too little moisture.
  • Moisture sensors which contain a metal oxide film or a polyelectrolyte film as the moisture-absorbing element have an exponential change in resistance in response to the relative air humidity in the gases to be examined.
  • Moisture sensors which contain a metal oxide have a relatively good heat resistance and respond quickly, but have a high temperature resistance coefficient, so that the temperature compensation mentioned above must also be taken into account in precision measurements.
  • Moisture sensors of this type generally have a gas cross section which is much too small, so that the dwell time of the individual gas molecules on the reaction layer only remains for a relatively short time, so that it is difficult to make a precise statement regarding the moisture of the gas. Furthermore are in the case of the moisture sensors described above, the surfaces which come into contact with the gas to be examined are relatively small, which also affects the accuracy of the moisture determination of the gas.
  • the moisture sensor consists of a tubular material with a gas inlet and a gas outlet and a mandrel located centrally in the tubular material, on which there are at least two electrically conductive windings.
  • This moisture sensor is characterized in that the individual windings are electrically separated from one another with minimal gaps;
  • a phosphorus pentoxide (P2O5) is applied to the windings, which also fills the spaces between the windings, and the distances between the tubular material and the central mandrel with the windings applied are minimal in order to keep the residence time of the gas under investigation to make maximum.
  • the design of the moisture sensor described above has a particularly favorable effect if the electrically conductive windings are made from high-purity platinum. According to the invention, the fact that the spacing between the individual turns on the insulating mandrel in the middle of the tubular material is less than 100 ⁇ m also has an advantageous effect when designing the moisture sensor described above.
  • the centering of the central dome in the tubular material is achieved, on the one hand, by holding points at one end of the central dome, which space the mandrel from the inner wall of the tubular material and, on the other hand, by a pinch point on the opposite side of the central mandrel is supported. It has also proven to be particularly advantageous to choose the voltage that is applied to the electrodes in such a way that it is close to 80 V.
  • a particularly important point of the invention is seen in the fact that the phosphorus pentoxide layer is applied homogeneously to the windings on the central mandrel and that the spaces between the individual windings are filled homogeneously with the phosphorus pentoxide layer.
  • Quartz glass is considered favorable for the use of both the tubular material and for the central mandrel.
  • FIG. 3 shows a longitudinal section of a moisture sensor according to the invention
  • Moisture sensor made of two tubular materials which are connected to one another by a tubular intermediate piece; 5 shows a cross section through one leg of the U-shaped moisture sensor;
  • FIG. 6 shows an enlarged longitudinal sectional view of a leg of the moisture sensor according to the invention.
  • This moisture sensor consists of two tubular legs 10 and 11, which have a length of approximately 120 to 130 mm and are connected by a tubular connecting piece 12 to a U-tube or to a communicating tube.
  • the material, both of the legs 10 and 11 and the connecting piece 12, is expediently to be made from quartz glass, since this has a relatively high heat resistance and the temperature-dependent coefficient of expansion is relatively low. In addition, it is transparent, which is essential for some experimental arrangements.
  • the quartz glass capillary which represent the legs of the U-tube, are open on one side and closed on the opposite side 7.
  • a carrier gas stream to be examined is connected to one of the openings (1, 2) and leaves the communicating tube on the other side, i.e. in the present case through opening 2 of the other leg again the U-tube. It does not matter at which point the gas supply or gas outlet is connected. It is therefore optional which side serves the gas inlet 1 or the gas outlet 2.
  • a mandrel 3 is attached in the center of each of the pipe legs 10 and 11, which also advantageously consists of quartz glass.
  • This mandrel 3 extends almost over the entire length of the leg, so that essentially the inside diameter of the tubular leg is filled by the mandrel 3.
  • On this mandrel 3 there are two electrically other separate platinum windings 4, which also extend over the entire length of the mandrel, but are not connected to one another at the gas openings.
  • these two windings each represent an electrode to which a voltage can be applied.
  • the other ends of the two electrodes are led gas-tight out of the quartz glass material on the opposite side 7 of the tubular quartz glass capillary of each leg, ie these ends 7 are fused to the electrode ends 6.
  • there are consequently 4 connection wires outside the moisture cell which can be used for the electrical connection.
  • the effective effective gas cross section is determined by the space between the mandrel 3 and the leg tube wall 5. More precisely, the distance between the windings 4 with the phosphor oxide layer thereon and the capillary wall 5. "For the response probability or the sensitivity of the moisture sensor according to the invention, it is extremely important to minimize the effective gas cross section so that the gas or the moisture contained here rinses the measuring windings sufficiently long and intensively, thereby increasing the sensitivity, since the gas to be examined is forced to remain on the probe material for a long time. A relatively long distance is also decisive for the sensitivity. which is generally not the case with conventional moisture measuring probes.
  • the U-shaped arrangement of the two quartz glass capillaries leads the gas through the two legs 10, 11, the effective gas cross section remaining constant over the entire leg length.
  • a very important element for the proper functioning of the moisture sensor according to the invention is the centering or mounting of the non-conductive dome 3 in the middle of the quartz glass capillary or of the legs 10 and 11. This is done on the one hand by two holding points 8 on the connection 12 between the legs of the domes, and by pinching points 9 of the legs 10, 11 on the opposite side in the vicinity of the entrances and exits 1, 2 of the communicating tube.
  • the windings 4 expediently consist of ultra-pure platinum tapes with the dimensions 0.1 x 0.014 mm, which are wound on the mandrel 3 with a certain pitch.
  • the ultra-pure platinum strips are applied to the mandrel 3 at a certain distance, which is smaller than 100 ⁇ m.
  • the external structure of the moisture sensor is shown again in FIG. 4.
  • the parts labeled 10 and 11 represent the two legs of the U-tube, which are connected by a tubular intermediate piece 12.
  • the total length of the moisture sensor is approximately 130 mm.
  • the distance between the two legs 10 and 11 of the U-tube can be between 15 and 20 mm.
  • the diameter of the legs 10, 11 was chosen to be 3.2 mm in the present case. It is particularly important for the production that the tubular connecting piece 12 is attached at approximately one fifth of the total length of the tubular material of the legs 10 and 11.
  • FIG. 5 shows the cross section of a leg 10 or 11.
  • the Quartz glass mandrel 3 In the middle is the quartz glass mandrel 3, on which the platinum winding is already applied.
  • the Obst ⁇ layer 13 therefore consists of one or two platinum windings and a coating of phosphorus pentoxide ⁇ - 2 ⁇ ___) comes ⁇ r the m ⁇ the gas cross section 14 in contact.
  • the gas cross section 14 is delimited on the one hand by the inner wall of the quartz glass capillary 5 and on the other hand by the phosphorus pentoxide layer. If possible, this gas cross section should be very small, so that the flow velocity of the gas to be measured becomes very small, so that the residence time of the gas becomes long.
  • FIG. 6 shows an enlarged longitudinal section of a leg 10 or 11 of the U-tube.
  • the windings 4 are wound on the quartz glass dome 3 with a certain pitch, the gaps between the individual windings 4 being identified by white lines.
  • the pinch points 9 provided for holding the mandrel 3 can be clearly seen in one leg of the U-tube.
  • the winding length in the present case, the mandrel 3 is between 80 and 100 mm.
  • the exact material specification of the dome 3 is N16B, which has a diameter of 1.5 mm.
  • a phosphorus pentoxide (P 2 0 5 ) is used for the coating of the windings 4, which is known as an extremely hygroscopic substance.
  • the electrical conductivity of the phosphorus pentoxide is extremely low when dry and extremely high when wet.
  • the phosphorus pentoxide is applied between the respective platinum bonds using a special process according to the invention in such a way that homogeneous coverage is ensured over the entire length of the leg.
  • a voltage of 80 V DC is connected to the individual electrical connections, ie to one end of the electrodes.
  • the windings are coated in various process steps.
  • the entire measuring cell is flushed with 65% HNO3 (nitric acid) using a suitable liquid transport system (pump).
  • the amount of solution used is 150 ml.
  • the cell is then cleaned with the solvent acetone and dried.
  • the amount of solution of the acetone is also 150 ml.
  • a mixture in a ratio of 10: 1 of acetone and phosphoric acid is then prepared and passed through the measuring cell.
  • the amount of mixture is also 150 ml.
  • the cell is then dry. Air is connected and flows through, a DC voltage of 80 V being simultaneously applied here.
  • the electrical current flowing in this process splits off water from the phosphoric acid and the phosphorus pentoxide (P 2 0 5 ) is formed.
  • the moisture sensor created in this way has an extremely small gas cross section, as a result of which an extremely long residence time of the gas to be examined is achieved. Furthermore, an extremely high response probability is achieved with the moisture sensor according to the invention, which is due, among other things, to the fact that the interstices between the turns of the individual platinum turns are smaller than 100 ⁇ m. Another advantage of the moisture sensor described above is that the entire measuring surface, which is coated with phosphorus pentoxide, is relatively large.

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electrochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Molecular Biology (AREA)
  • Combustion & Propulsion (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

Un appareillage qui fonctionne selon un procédé de thermoanalyse se distingue des procédés de mesure par voie humide connus, notamment par le fait que des calculs compliqués ne sont pas nécessaires et que l'on n'utilise pas des substances chimiques toxiques qui présentent par la suite le problème de leur élimination. L'appareillage comprend essentiellement une voie d'analyse à quatre composants de base; le tamis moléculaire (1), la cellule thermique (2), l'unité de pyrolyse (3) et la cellule à eau (4), ainsi qu'une partie électronique qui évalue les signaux électriques mesurés et les représente de manière appropriée sur un moniteur. L'invention concerne en outre un détecteur d'humidité dont la probabilité de réponse par rapport aux détecteurs d'humidités comparables classiques a pu être considérablement améliorée. La précision de mesure est également accrue, étant donné que le temps de séjour du gaz à analyser est extrêmement long, compte tenu des dimensions très réduites de la section transversale d'exposition au gaz de deux capillaires en U (10, 11) en verre reliés l'un à l'autre. La structure de ce détecteur d'humidité consiste essentiellement en au moins deux enroulements (4) enroulés sur une broche en verre quartzeux (3), et en électrodes électriquement isolées l'une de l'autre sur lesquelles on applique une substance fortement hygroscopique (P2O5) dont la conductivité se modifie fortement en fonction de la teneur en humidité.
EP92924722A 1991-12-11 1992-12-11 Appareillage et procede de detection de traces d'humidite dans des substances solides et liquides Withdrawn EP0616691A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4140831 1991-12-11
DE19914140831 DE4140831A1 (de) 1991-12-11 1991-12-11 Feuchtigkeitssensor
PCT/EP1992/002878 WO1993012418A2 (fr) 1991-12-11 1992-12-11 Appareillage et procede de detection de traces d'humidite dans des substances solides et liquides

Publications (1)

Publication Number Publication Date
EP0616691A1 true EP0616691A1 (fr) 1994-09-28

Family

ID=6446797

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92924722A Withdrawn EP0616691A1 (fr) 1991-12-11 1992-12-11 Appareillage et procede de detection de traces d'humidite dans des substances solides et liquides

Country Status (3)

Country Link
EP (1) EP0616691A1 (fr)
DE (1) DE4140831A1 (fr)
WO (1) WO1993012418A2 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI98567C (fi) * 1993-09-29 1997-07-10 Vaisala Oy Impedanssianturi, etenkin radiosondikäyttöön, sekä menetelmä anturin valmistamiseksi
US5589085A (en) * 1995-08-04 1996-12-31 Meeco, Incorporated Process of manufacturing a detecting unit for an electrolytic cell with thin film electrodes
DE19532987C1 (de) * 1995-09-07 1996-11-28 Sartorius Gmbh Vorrichtung zur Bestimmung des Wassergehaltes von Proben
EP2994536B1 (fr) 2013-05-08 2017-06-14 Roche Diabetes Care GmbH Stabilisation d'enzymes par de l'acide nicotinique
EP3074524B1 (fr) 2013-11-27 2019-11-06 Roche Diabetes Care GmbH Composition comprenant des phosphores de conversion ascendante pour détecter un analyte
EP2927319A1 (fr) 2014-03-31 2015-10-07 Roche Diagnostics GmbH Immobilisation d'enzyme à charge élevée par réticulation
RU2652656C1 (ru) * 2017-06-29 2018-04-28 Общество с ограниченной ответственностью "Научно-производственное предприятие ОКБА" (ООО "НПП ОКБА") Гигрометр
CN108287185B (zh) * 2018-01-09 2024-01-12 南京信息工程大学 一种探空湿度传感器、制备方法、探空湿度测量系统及测量方法
DE102018205347A1 (de) 2018-04-10 2019-10-10 Deutsches Zentrum für Luft- und Raumfahrt e.V. Verfahren zum Bestimmen einer Materialfeuchte in einer Materialprobe und Materialfeuchtemesszelle

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH476996A (de) * 1967-03-21 1969-08-15 Vitkovice Zelezarny Verfahren und Vorrichtung zur automatischen Bestimmung des Wassergehalts von Schüttgütern
US4354244A (en) * 1980-02-25 1982-10-12 Eur-Control M&D, U.S.A., Inc. Method and apparatus for determining the moisture content of particulate material that may contain an unknown amount of moisture in a frozen state
DE3908934A1 (de) * 1989-03-18 1990-09-20 Msi Elektronik Gmbh Vorrichtung zur gasanalyse

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9312418A3 *

Also Published As

Publication number Publication date
DE4140831A1 (de) 1993-07-08
WO1993012418A3 (fr) 1993-07-22
WO1993012418A2 (fr) 1993-06-24

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