DE2429482C3 - Device for measuring and / or monitoring temperatures, levels and / or flow conditions of electrically conductive liquids of high specific heat - Google Patents
Device for measuring and / or monitoring temperatures, levels and / or flow conditions of electrically conductive liquids of high specific heatInfo
- Publication number
- DE2429482C3 DE2429482C3 DE19742429482 DE2429482A DE2429482C3 DE 2429482 C3 DE2429482 C3 DE 2429482C3 DE 19742429482 DE19742429482 DE 19742429482 DE 2429482 A DE2429482 A DE 2429482A DE 2429482 C3 DE2429482 C3 DE 2429482C3
- Authority
- DE
- Germany
- Prior art keywords
- measuring
- high specific
- electrically conductive
- specific heat
- levels
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
- G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
- G01F1/69—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element of resistive type
- G01F1/692—Thin-film arrangements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
- G01F1/6847—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
- G01F23/246—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid thermal devices
- G01F23/247—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid thermal devices for discrete levels
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
- G01K7/223—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor characterised by the shape of the resistive element
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/10—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables
- G01P5/12—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables using variation of resistance of a heated conductor
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Thermal Sciences (AREA)
- Nonlinear Science (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Thermistors And Varistors (AREA)
Description
Die Erfindung betrifft eine Vorrichtung zum Messen und/oder Überwachen von Temperaturen, Niveauhöhen und/oder Strömungszuständen elektrisch leitfähiger Flüssigkeiten hoher spezifischer Wärme, insbesondere von Wass<*. welche als Fühler einen temperaturabhängigen Widerstand mit Klemmkontaktierung besitzt, welcher zur Isolierung mit einem Schrumpfschlauch umhüllt istThe invention relates to a device for measuring and / or monitoring temperatures and levels and / or flow states of electrically conductive liquids of high specific heat, in particular by Wass <*. which as a sensor a temperature-dependent Has a resistance with clamp contact, which is used for insulation with a shrink tube is wrapped
Aus der DE-OS 21 07 365 ist eine schrumpfschlauchumhüllte Kaltleiterkombinalion mit Klemmkontaktierung für die Entmagnetisierung von Farbfernsehgeräten bekannt Ein derartiger Aufbau eignet sich nicht zum Einsatz in elektrisch leitfähigen Flüssigkeiten hoher spezifischer Wärme, da die Umhüllung an einer Seite offen ist und da andererseits die Kontaktierung der Kaltleiter nur an sehr kleinen Rächen erfolgt Dies hst zur Folge, daß der Wärmeübergang von der Kontaktelektrode auf den Kaltleiter sehr gering ist was eine große Zeitkonstante der Kombination zur Folge hat Unter Zeitkonstante wird hierbei diejenige Zeit verstanden, die der Kaltleiter benötigt bis seine Temperatur derjenigen der Umgebung angepaßt istFrom DE-OS 21 07 365 a shrink tubing is covered PTC thermistor combination with terminal contact for the demagnetization of color television sets known. Such a structure is not suitable for Use in electrically conductive liquids with high specific heat, as the casing is on one side is open and since, on the other hand, the PTC thermistors are only contacted at very small areas As a result, the heat transfer from the contact electrode to the PTC thermistor is very low, which is a results in a large time constant for the combination. Time constant here is the time understood that the PTC thermistor needs until its temperature is adapted to that of the environment
Weiterhin sind aus der »Siemens-Zeitschrift« 1969, Heft 4, S. 392 bis 394, und Heft 9, S. 793 bis 7%, Kaltleiter mit Schrumpfschla'ichumhüllung bekannt Die bekannten Kaltleiter dienen zur Temperaturüberwachung und zum übertemperaturschutz für temperaturgefährdete Maschinen und Einrichtungen, insbesondere Elektromotoren. Die bekannten schrumpfschlauchumhüllten Kaltleiter haben angelötete Anschlußdrähte und weisen eine Kunststoffisolierung auf. Sie eignen sich nicht zum Einsatz in Flüssigkeiten hoher spezifischer Wärme, da beim Eintauchen des Fühlers der Temperaturschock so stark ist, daß nach einigen Meßtakten Ablösung der Lötstellen eintreten kann.Furthermore, from the "Siemens magazine" 1969, issue 4, p. 392 to 394, and issue 9, p. 793 to 7%, PTC thermistors Known with shrink tubing The known ones PTC thermistors are used for temperature monitoring and excess temperature protection for those at risk of temperature Machines and devices, in particular electric motors. The well-known PTC thermistors covered with shrink tubing have soldered connection wires and have plastic insulation. They are not suitable for Use in liquids with high specific heat, as the temperature shock occurs when the probe is immersed it is strong that after a few measuring cycles the soldering points can become detached.
Aufgabe der Erfindung ist es, eine Vorrichtung zum Messen und/oder überwachen von Temperaturen, Niveauhöhen und/oder Strömungszuständen elektrisch leitfähiger Flüssigkeiten anzugeben, mit welcher die vorstehend aufgeführten Schwierigkeiten umgangen werden.The object of the invention is to provide a device for measuring and / or monitoring temperatures, Indicate level heights and / or flow states of electrically conductive liquids with which the difficulties listed above can be circumvented.
ι *>ι *>
Dies wird bei der eingangs beschriebenen Vorrichtung erfindungsgemäß dadurch gelöst, daß die Kontaktelektroden aus federnden Blechstreifen bestehen, deren eines Ende mit dem Ende einer als Stromzuführung dienenden Liitze verlötet ist, und welche spiralförmig um dieses Ende der Litze aufgewickelt sind, und daß das offene Ende des Schrumpfschlauches mit einem Kunststofftropfen verschlossen istIn the device described at the outset, this is achieved according to the invention in that the contact electrodes consist of resilient sheet metal strips, one end of which with the end of a power supply serving wire is soldered, and which spiral around this end of the braid are wound, and that the open end of the shrink tube with a Plastic drop is closed
Als temperaturabhängiger Widerstand -kann entweder ein Heißleiter oder ein Kaltleiter verwendet werden.As a temperature-dependent resistor, either a thermistor or a PTC thermistor can be used.
Die Vorteile der Erfindung werden anhand der Zeichnung, welche ein Ausführungsbeispiel der erfindungsgemäßen Vorrichtung darstellt aufgezeigt In den zugehörigen Figuren zeigtThe advantages of the invention are based on the drawing, which shows an embodiment of the invention Device shows shown in the accompanying figures shows
Fig. 1 einen Längsschnitt durch die erfindungsgemäße Vorrichtung undFig. 1 is a longitudinal section through the inventive Device and
Fig.2 einen Querschnitt längs der Ebene H-II der Fig. 1.FIG. 2 shows a cross section along the plane H-II of FIG. 1.
In den F i g. 1 und 2 ist mit 11 eine Kaltleiterscheibe bezeichnet, die eine sperrschichtfreie Metallbelegung 12 aufweist Die Anschlußlitzen !3 sind an ihrem oberen Ende abisoliert; an dieses obere Ende ist ein Blechstreifen 14 angelötet und spiralförmig um das Ende herumgewickelt Als Material für den Blechstreifen 14 wird dabei vorzugsweise verzinnte Bronzefolie von 0,2 mm Dicke verwendetIn the F i g. 1 and 2 is a PTC thermistor disk with 11 denotes, which has a barrier layer-free metal coating 12 The connecting strands! 3 are at their upper Stripped end; a sheet metal strip 14 is soldered to this upper end and spiraled around the Wrapped around the end The material for the sheet metal strip 14 is preferably tinned bronze foil 0.2 mm thick is used
Die spiralförmig- aufgewickelten Blechstreifen 14 werden mittels des als Umhüllung und Isolierung dienenden Schrumpfschlauches 15 gegen die metallisierten Kaltleiterfläcben gedrückt Durch die Federwirkung der Blechstreifen entsteht dabei ein bei allen auftretenden Betriebsbedingungen sicherer Kontakt, welcher insbesondere durch den Temperaturschock beim Eintauchen in die Flüssigkeit hoher spezifischer Wärme nicht zerstört werden kann. Andererseits gewährt der spiralförmig aufgewickelte Blechstreifen 24 durch seine großflächige Kontaktstellen einen guten Wärmeübergang, so daß die Vorrichtung eine niedrige Zcitkonstante aufweistThe spirally wound sheet metal strips 14 are by means of serving as a sheath and insulation shrink tubing 15 against the metallized PTC thermistor surfaces pressed. The spring action of the sheet metal strips creates one that occurs in all Operating conditions safe contact, which is particularly due to the temperature shock when immersed in the liquid of high specific heat cannot be destroyed. On the other hand, the Spirally wound sheet metal strips 24 a good heat transfer due to its large contact points, so that the device has a low rate constant
Um die für die Niveauabtastung und -messung erforderliche Dichtheit herzustellen, wird das offene Ende des Schrumpfschlauches 15 mittels eines Kunststofftropfens: 16 verschlossen.In order to produce the tightness required for level sensing and measurement, the open The end of the shrink tube 15 is closed by means of a plastic drop: 16.
Beim Betrieb wird der Kaltleiter durch eine angelegte Meßspannung bis in den Temperaturbereich des steilen Widerstandsanstiegs aufgeheizt wobei im Strom-Spannungs-Diagramm dieser Betriebszustand im Gebiet fallender Siirom-Spannungs-Kennlinie liegt Da in Flüssigkeit mehr Wärme abgeführt werden kann, befindet sich der Kaltleiter auf einer niedrigeren Temperatur als in Luft, d. h. er weist in Flüssigkeit einen niedrigeren Widerstandswert auf. Daraus resultiert ein größerer Strom durch den Kaltleiter, wenn er sich in Flüssigkeit befindetDuring operation, the PTC thermistor is brought into the temperature range of the steep by an applied measuring voltage Resistance increase heated with this operating state in the area in the current-voltage diagram falling Siirom voltage characteristic curve is Da in Liquid can dissipate more heat, the PTC thermistor is at a lower level Temperature than in air, d. H. it has a lower resistance value in liquid. This results in a higher current through the PTC thermistor when it is in liquid
Bei einem Ausführungsbeispiel der erfindungsgemäßen Vorrichtung wurde ein Kaltleiter der Nenntemperatur (Beginn des stellen Widerstandsanstiegs) von 80° C verwendet, welcher bei 25° C einen Widerstandswert von 60 Ohm hatte. Bei dieser Ausführungsform ergaben sich bei einer angelegten Spannung von 20 V in Luft Stromwerte von etwa IO mA und in Wasser solche von ungefähr 50 mA.In one embodiment of the device according to the invention, a PTC thermistor of the nominal temperature was used (Start of the increase in resistance) of 80 ° C is used, which has a resistance value at 25 ° C of 60 ohms. In this embodiment, an applied voltage of 20 V resulted in air Current values of around IO mA and in water around 50 mA.
Für andere Flüssigkeiten ergeben sich je nach Wärmewiderstand andere, aber ähnliche Werte.For other liquids, different but similar values result depending on the thermal resistance.
Schaltungen, in denen die erfindungsgemäße Vorrichtung eingesetzt werden kann, sind z. B. in der DE-PS 15 73 085, die eine elektronische Thermistorkompensa-Circuits in which the device according to the invention can be used are, for. B. in DE-PS 15 73 085, which has an electronic thermistor compensation
tionsschaltung zur Oberfüllsicherung von Flüssigkeitstanks betrifft, und in der DE-PS 15 73 090, die ein Verfahren und eine Schaltungsanordnung zur Sicherung von Flüssigkeitstanks gegen Oberfüllung betrifft, beschrieben.tion circuit for overfill protection of liquid tanks concerns, and in DE-PS 15 73 090, which a Process and a circuit arrangement for securing liquid tanks against overfilling concerns, described.
Hierzu 1 Blatt Zeichnungen1 sheet of drawings
Claims (2)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19742429482 DE2429482C3 (en) | 1974-06-20 | 1974-06-20 | Device for measuring and / or monitoring temperatures, levels and / or flow conditions of electrically conductive liquids of high specific heat |
AT364075A AT338015B (en) | 1974-06-20 | 1975-05-13 | TEMPERATURE PROBE FOR USE IN A DEVICE FOR MEASURING AND / OR MONITORING TEMPERATURES, LEVELS AND / OR CONDITIONS OF ELECTRICALLY CONDUCTIVE LIQUIDS OF HIGH SPECIFIC WARMTH |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19742429482 DE2429482C3 (en) | 1974-06-20 | 1974-06-20 | Device for measuring and / or monitoring temperatures, levels and / or flow conditions of electrically conductive liquids of high specific heat |
Publications (3)
Publication Number | Publication Date |
---|---|
DE2429482A1 DE2429482A1 (en) | 1976-01-02 |
DE2429482B2 DE2429482B2 (en) | 1978-05-03 |
DE2429482C3 true DE2429482C3 (en) | 1979-01-18 |
Family
ID=5918440
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19742429482 Expired DE2429482C3 (en) | 1974-06-20 | 1974-06-20 | Device for measuring and / or monitoring temperatures, levels and / or flow conditions of electrically conductive liquids of high specific heat |
Country Status (2)
Country | Link |
---|---|
AT (1) | AT338015B (en) |
DE (1) | DE2429482C3 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3232333C2 (en) * | 1982-08-31 | 1984-06-07 | Siemens AG, 1000 Berlin und 8000 München | Level sensor for liquids, in particular for determining the level of the brake fluid or the tank content in motor vehicles |
FR2559797B1 (en) * | 1984-02-17 | 1986-12-05 | Esswein Sa | DEVICE FOR CONTROLLING THE WATER LEVEL AND THE TEMPERATURE OF THE SAME IN A WASHING MACHINE |
JPS6258721U (en) * | 1985-10-02 | 1987-04-11 | ||
DE4003638A1 (en) * | 1989-02-10 | 1990-08-23 | Hiss Eckart | Flow rate monitor using electric temp. difference measurement - has hollow cylindrical measuring pin containing temp. measuring elements and electric heating element |
DE4116355C2 (en) * | 1991-05-18 | 2000-05-18 | Wilo Gmbh | Sensor |
DE102019111609A1 (en) * | 2019-05-06 | 2020-11-12 | Miele & Cie. Kg | Temperature measuring probe and process for their manufacture |
-
1974
- 1974-06-20 DE DE19742429482 patent/DE2429482C3/en not_active Expired
-
1975
- 1975-05-13 AT AT364075A patent/AT338015B/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
AT338015B (en) | 1977-07-25 |
DE2429482B2 (en) | 1978-05-03 |
DE2429482A1 (en) | 1976-01-02 |
ATA364075A (en) | 1976-11-15 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
C3 | Grant after two publication steps (3rd publication) | ||
EHJ | Ceased/non-payment of the annual fee |