CA1185455A - Gas density indicator - Google Patents
Gas density indicatorInfo
- Publication number
- CA1185455A CA1185455A CA000414253A CA414253A CA1185455A CA 1185455 A CA1185455 A CA 1185455A CA 000414253 A CA000414253 A CA 000414253A CA 414253 A CA414253 A CA 414253A CA 1185455 A CA1185455 A CA 1185455A
- Authority
- CA
- Canada
- Prior art keywords
- vessel
- gas
- encapsulation
- density
- indicator
- 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
- 238000005538 encapsulation Methods 0.000 claims abstract description 30
- 238000009434 installation Methods 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 230000008602 contraction Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/10—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by observing bodies wholly or partially immersed in fluid materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
- H01H33/02—Details
- H01H33/53—Cases; Reservoirs, tanks, piping or valves, for arc-extinguishing fluid; Accessories therefor, e.g. safety arrangements, pressure relief devices
- H01H33/56—Gas reservoirs
- H01H33/563—Gas reservoirs comprising means for monitoring the density of the insulating gas
Landscapes
- Immunology (AREA)
- Pathology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
- Gas-Insulated Switchgears (AREA)
- Measuring Fluid Pressure (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A gas density indicator for checking the density of an electro-negative gas comprises a gas-tight vessel arranged in the encapsulation of an electric switching installation. The vessel is at a predetermined internal pressure. The position of the vessel bottom can vary in the event of density change of the electro-negative gas to indicate the change in density. An adjust-able external stop extends below the vessel bottom.
A gas density indicator for checking the density of an electro-negative gas comprises a gas-tight vessel arranged in the encapsulation of an electric switching installation. The vessel is at a predetermined internal pressure. The position of the vessel bottom can vary in the event of density change of the electro-negative gas to indicate the change in density. An adjust-able external stop extends below the vessel bottom.
Description
CKGROUND OF THE INVENTION
This invention relates to gas density indicators in general, and more particularly to a gas density indicator for checking the density of an electro-negative gas for an encapsulated switching installation.
A gas density indicator, which comprises a body, the weight of which, depending on the buoyancy, is indicated, is known ~or use in checking the density of an electro-negative gas in a switching ins-tallation. The buoyant body may be a thin-walled glass sphere which, however, is very fragile. Typically, the body is fastened to one arm of a beam balance, at the other arm of which a counterweight is provided which has a specific gravi-ty different from the buoyant body. Pressure changes of the electro-negative gas occurring due to temperature changes influence the position of the balance beam only for a short time, if at all. The gas content of the buoyant body follows the temperature with possibly only a small amount of inertia and, therefore, follows the pressure of the ambient gas. In the event of changes of the temperature and therefore, the pressure, a state of equilibrium is thus already reestablished in a short time, which can be observed by the position of the balance beam. If, however, the buoyancy force acting on the buoyant body drops due to loss of electro-negative gas, the buoyant body and the balance beam associated with it also drop. Through the change of position of the balance beam, gas losses can therefore be ascertained visually, but only as long as the fragile buoyant body and the bearing of the balance beam are intact. The specific gravity of the buoyant body can change, for - 1 - ~
~5'~
instance, due -to condensation. The bearing of the balance beam is sensitive to condensation and shock (DE-OS 27 11 797).
An arc protection device for gas insulated completely metal-encapsulated high voltage switching installations, in which the interior of an accordion bellows is constantly at the internal pressure of the associa-ted switching installation is also known.
However, only pressure changes of the insulating gas can be indicated with the known device (German Petty Patent 79 29 553).
It is furtilermore known to compensate temperature influences on closed manometer vessels, for instance, by bi-metal strips (German Patent 857,691, DE-AS 11 70 159).
It is an object of the present invention to make the gas density indicator of the general type described above particularly rugged in a simple manner.
SUMMARY OF THE INVENTION
The invention provides a gas density indicator for check-ing the density of an electro-negative gas in the encapsulation of an electric switching installation comprising: a) a gas-tight vessel, which is at a predetermined internal pressure, disposed within the encapsulation; b) said vessel having a head wall, sides and a bottom, the position of said bottom being variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change; c) an external stop e~tending below the vessel bottom at an adjustable distance; and d) a viewing window formed in said encapsulation, said viewing window having control marks thereon and indicator means, associated with the bottom of said vessel, disposed opposite said window, whereby a measure of the gas density may be obtained by viewing, through said window, the position of said means associated with said bottom with respect to said con-trol marks wi-th said apparatus entirely within said encapsulation.
The invention also provides a method for adjusting a gas densi-ty indica-tor for checking the density of an electro-negative gas in -the encapsulation o:E an electric swi-tching installation said indica-tor including a gas-tigllt vessel, which is a-t a pre-de-termined in-ternal pressure, disposed within the encapsulation;
said vessel having a head wall, sides and a bottom, the position of said bot-tom variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change; and an external stop extending below the vessel bottom at an adjustable distance comprising:
a) first evacuating the encapsulation with the vessel open; b) limiting the expansion of the vessel occurring in the process by an external stop; c) then sealing the vessel; and d) subsequently admitting the insulating gas into the encapsulation up to the desired pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross section of the wall of an encapsula-tion of an electric switching installation showing a gas density - 2a -~ ~S~55 indicator according to the present invention arranged in the wall with an extension.
Figure 2 is a cross section of through two walls, abut-ting at right angles, of an encapsulation of an electric switching installation showing a gas density indicator with two different indicator members arranged behind the one wall.
DETAILED DESCRIPTION
In Figure 1, the wall 1 of an encapuslation, not other-wise shown, of an electric switching installation is illustrated.
The encapsulation contains an electro-negative gas such as SF6 or the like, which is at a pressure of, for instance, 1.3 bar.
Behind the wall 1 is a gas-tight vessel 2 which is at a predetermined internal pressure of, for example, 1 bar in the starting condition. In the present case, the vessel 2 has side walls in the form of an accordion bellows closed off by a head wall 2a and a bottom 2b.
The head wall 2a of the vessel 2 is welded in a gas-tight manner into the wall 1.
The vessel bottom 2b can move in the longitudinal direction of the vessel 2 in the event of density changes of the electro-negative gas, while pressure changes of the electro-negative gas due to temperature changes exert no length changing influence on the vessel 2. The latter can be explained by the fact that temperature equalization occurs in a short time between the electro-negative gas and the gas volume of the vessel when the temperature of -the electro-negative gas changes due to a change of the ambient temperature or a disturbance arc. With the temperature 5~
remaining the same, however, the pressure difference between the electro-negative gas and the gas content of the vessel 2 also remains the same, so that no forces occur which lengthen or shorten -the vessel 2.
The arrangement behaves entirely differently iE the degree oE filling of -the encapsulation is changed. There, an isothermal densi-ty change oE -the electro-ne~atlve gas occurs r whereby the vessel 2 expands or contracts, depending on whether ~as is filled in or escapes, until the density of its gas content is equal to the instantaneous density of the electro-negative gas.
The then occurring change in position of the vessel bottom 2b is utilized for indicating the change of the density ratio.
In the embodiment of Figure 1, a rod 3 is fastened to the vessel bottom 2b. The rod 3 extends through the head wall 2a of the vessel 2 and into an extension 4 which protrudes from the wall 1.
An indicating member 5 which is visible in windows 6 of the extension 4 is fastened to the free end of the rod 3. The upper edge and the lower edge of the windows 6 can serve as cO,,~,~,J
fiduciari marks for position changes of the indicating member 5.
The extension 4, however, may also be entirely transparent and may co t,~/
have, for instance, lines thereon for use as ~ue~Ey marks (not shown).
The arrangement described is adjusted as follows:
First, the encapsulation is evacuated with the vessel 2 open. The vessel 2 then expands under the prevailing air pressure until it makes contact with an external stop 7. Then the vessel 2 sealed off at 2c. Finally, the insulating gas is pumped into the encapsulation up to the desired pressure.
As soon as the isothermically increasing pressure of the insulating gas exceeds the internal pressure of vessel 2, vessel 2 contracts. The shortening can be read at the indicating member 5.
To avoid too great a shortening in case the pressure of the insulating gas exceeds the desired pressure, an internal stop 8 is arranged in the vessel 2. In the illustrated embodiment, the in-ternal stop 8 is fastened to the vessel bottom 2a. Its free end is spaced a distance from the head wall 2a which distance is still within a permissible contraction of the vessel 2.
Figure 2 illustrates a second embodiment of the present invention installed within a switching installation encapsulation 10 .
As shown, a viewing window through which position changes of the vessel bottom 2b can be observed, can be arranged in the encapsulation. The viewing window 11 may also be provided with Q /
f~duc-iar-~ marks. The vessel bottom, the vessel, the internal stop and the external stop have same reference numbers as in Figure 1.
Due to the arrangement described, the rod 3, the extension 4 and the indicating member 5 can be dispensed with as compared to the embodiment of Figure 1.
The bottom 2b in Figure 2 may have, however, an ex-tension 12 brought up to the viewing window 11, as shown dash-dotted.
If no viewing window 11 is desired or possible in the switching installation encapsulation 10, a permanent magnet 13 can be fastened to the extension 12 of the vessel bottom 2b or, in a 5~
manner not shown, to the vessel bottom 2b itsel~, by means of whieh a magnetizable indicator 14 loeated outside the switching installation encapsulation can be influenced.
If the swi-tching installation encapsulation does not consist of magne-tizable ma-terial, the indicator 14 can be set directly to the eneapsulation 10, as shown.
The arran~ement aeeordin~ to Figure 2 is adjusted in the same manner as the adjustment of the arrangement of Figure 1.
This invention relates to gas density indicators in general, and more particularly to a gas density indicator for checking the density of an electro-negative gas for an encapsulated switching installation.
A gas density indicator, which comprises a body, the weight of which, depending on the buoyancy, is indicated, is known ~or use in checking the density of an electro-negative gas in a switching ins-tallation. The buoyant body may be a thin-walled glass sphere which, however, is very fragile. Typically, the body is fastened to one arm of a beam balance, at the other arm of which a counterweight is provided which has a specific gravi-ty different from the buoyant body. Pressure changes of the electro-negative gas occurring due to temperature changes influence the position of the balance beam only for a short time, if at all. The gas content of the buoyant body follows the temperature with possibly only a small amount of inertia and, therefore, follows the pressure of the ambient gas. In the event of changes of the temperature and therefore, the pressure, a state of equilibrium is thus already reestablished in a short time, which can be observed by the position of the balance beam. If, however, the buoyancy force acting on the buoyant body drops due to loss of electro-negative gas, the buoyant body and the balance beam associated with it also drop. Through the change of position of the balance beam, gas losses can therefore be ascertained visually, but only as long as the fragile buoyant body and the bearing of the balance beam are intact. The specific gravity of the buoyant body can change, for - 1 - ~
~5'~
instance, due -to condensation. The bearing of the balance beam is sensitive to condensation and shock (DE-OS 27 11 797).
An arc protection device for gas insulated completely metal-encapsulated high voltage switching installations, in which the interior of an accordion bellows is constantly at the internal pressure of the associa-ted switching installation is also known.
However, only pressure changes of the insulating gas can be indicated with the known device (German Petty Patent 79 29 553).
It is furtilermore known to compensate temperature influences on closed manometer vessels, for instance, by bi-metal strips (German Patent 857,691, DE-AS 11 70 159).
It is an object of the present invention to make the gas density indicator of the general type described above particularly rugged in a simple manner.
SUMMARY OF THE INVENTION
The invention provides a gas density indicator for check-ing the density of an electro-negative gas in the encapsulation of an electric switching installation comprising: a) a gas-tight vessel, which is at a predetermined internal pressure, disposed within the encapsulation; b) said vessel having a head wall, sides and a bottom, the position of said bottom being variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change; c) an external stop e~tending below the vessel bottom at an adjustable distance; and d) a viewing window formed in said encapsulation, said viewing window having control marks thereon and indicator means, associated with the bottom of said vessel, disposed opposite said window, whereby a measure of the gas density may be obtained by viewing, through said window, the position of said means associated with said bottom with respect to said con-trol marks wi-th said apparatus entirely within said encapsulation.
The invention also provides a method for adjusting a gas densi-ty indica-tor for checking the density of an electro-negative gas in -the encapsulation o:E an electric swi-tching installation said indica-tor including a gas-tigllt vessel, which is a-t a pre-de-termined in-ternal pressure, disposed within the encapsulation;
said vessel having a head wall, sides and a bottom, the position of said bot-tom variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change; and an external stop extending below the vessel bottom at an adjustable distance comprising:
a) first evacuating the encapsulation with the vessel open; b) limiting the expansion of the vessel occurring in the process by an external stop; c) then sealing the vessel; and d) subsequently admitting the insulating gas into the encapsulation up to the desired pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross section of the wall of an encapsula-tion of an electric switching installation showing a gas density - 2a -~ ~S~55 indicator according to the present invention arranged in the wall with an extension.
Figure 2 is a cross section of through two walls, abut-ting at right angles, of an encapsulation of an electric switching installation showing a gas density indicator with two different indicator members arranged behind the one wall.
DETAILED DESCRIPTION
In Figure 1, the wall 1 of an encapuslation, not other-wise shown, of an electric switching installation is illustrated.
The encapsulation contains an electro-negative gas such as SF6 or the like, which is at a pressure of, for instance, 1.3 bar.
Behind the wall 1 is a gas-tight vessel 2 which is at a predetermined internal pressure of, for example, 1 bar in the starting condition. In the present case, the vessel 2 has side walls in the form of an accordion bellows closed off by a head wall 2a and a bottom 2b.
The head wall 2a of the vessel 2 is welded in a gas-tight manner into the wall 1.
The vessel bottom 2b can move in the longitudinal direction of the vessel 2 in the event of density changes of the electro-negative gas, while pressure changes of the electro-negative gas due to temperature changes exert no length changing influence on the vessel 2. The latter can be explained by the fact that temperature equalization occurs in a short time between the electro-negative gas and the gas volume of the vessel when the temperature of -the electro-negative gas changes due to a change of the ambient temperature or a disturbance arc. With the temperature 5~
remaining the same, however, the pressure difference between the electro-negative gas and the gas content of the vessel 2 also remains the same, so that no forces occur which lengthen or shorten -the vessel 2.
The arrangement behaves entirely differently iE the degree oE filling of -the encapsulation is changed. There, an isothermal densi-ty change oE -the electro-ne~atlve gas occurs r whereby the vessel 2 expands or contracts, depending on whether ~as is filled in or escapes, until the density of its gas content is equal to the instantaneous density of the electro-negative gas.
The then occurring change in position of the vessel bottom 2b is utilized for indicating the change of the density ratio.
In the embodiment of Figure 1, a rod 3 is fastened to the vessel bottom 2b. The rod 3 extends through the head wall 2a of the vessel 2 and into an extension 4 which protrudes from the wall 1.
An indicating member 5 which is visible in windows 6 of the extension 4 is fastened to the free end of the rod 3. The upper edge and the lower edge of the windows 6 can serve as cO,,~,~,J
fiduciari marks for position changes of the indicating member 5.
The extension 4, however, may also be entirely transparent and may co t,~/
have, for instance, lines thereon for use as ~ue~Ey marks (not shown).
The arrangement described is adjusted as follows:
First, the encapsulation is evacuated with the vessel 2 open. The vessel 2 then expands under the prevailing air pressure until it makes contact with an external stop 7. Then the vessel 2 sealed off at 2c. Finally, the insulating gas is pumped into the encapsulation up to the desired pressure.
As soon as the isothermically increasing pressure of the insulating gas exceeds the internal pressure of vessel 2, vessel 2 contracts. The shortening can be read at the indicating member 5.
To avoid too great a shortening in case the pressure of the insulating gas exceeds the desired pressure, an internal stop 8 is arranged in the vessel 2. In the illustrated embodiment, the in-ternal stop 8 is fastened to the vessel bottom 2a. Its free end is spaced a distance from the head wall 2a which distance is still within a permissible contraction of the vessel 2.
Figure 2 illustrates a second embodiment of the present invention installed within a switching installation encapsulation 10 .
As shown, a viewing window through which position changes of the vessel bottom 2b can be observed, can be arranged in the encapsulation. The viewing window 11 may also be provided with Q /
f~duc-iar-~ marks. The vessel bottom, the vessel, the internal stop and the external stop have same reference numbers as in Figure 1.
Due to the arrangement described, the rod 3, the extension 4 and the indicating member 5 can be dispensed with as compared to the embodiment of Figure 1.
The bottom 2b in Figure 2 may have, however, an ex-tension 12 brought up to the viewing window 11, as shown dash-dotted.
If no viewing window 11 is desired or possible in the switching installation encapsulation 10, a permanent magnet 13 can be fastened to the extension 12 of the vessel bottom 2b or, in a 5~
manner not shown, to the vessel bottom 2b itsel~, by means of whieh a magnetizable indicator 14 loeated outside the switching installation encapsulation can be influenced.
If the swi-tching installation encapsulation does not consist of magne-tizable ma-terial, the indicator 14 can be set directly to the eneapsulation 10, as shown.
The arran~ement aeeordin~ to Figure 2 is adjusted in the same manner as the adjustment of the arrangement of Figure 1.
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A gas density indicator for checking the density of an electro-negative gas in the encapsulation of an electric switching installation comprising:
a) a gas-tight vessel, which is at a predetermined internal. pressure, disposed within the encapsulation;
b) said vessel having a head wall, sides and a bottom, the position of said bottom being variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change;
c) an external stop extending below the vessel bottom at an adjustable distance; and d) a viewing window formed in said encapsulation, said viewing window having control marks thereon and indicator means, associated with the bottom of said vessel, disposed opposite said window, whereby a measure of the gas density may be obtained by viewing, through said window, the position of said means associ-ated with said bottom with respect to said control marks with said apparatus entirely within said encapsulation.
a) a gas-tight vessel, which is at a predetermined internal. pressure, disposed within the encapsulation;
b) said vessel having a head wall, sides and a bottom, the position of said bottom being variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change;
c) an external stop extending below the vessel bottom at an adjustable distance; and d) a viewing window formed in said encapsulation, said viewing window having control marks thereon and indicator means, associated with the bottom of said vessel, disposed opposite said window, whereby a measure of the gas density may be obtained by viewing, through said window, the position of said means associ-ated with said bottom with respect to said control marks with said apparatus entirely within said encapsulation.
2. A gas density indicator according to claim 1, wherein said vessel comprises an accordion bellows, closed gas-tight at both ends.
3. A gas density indicator according to claim 2, wherein said indicator means comprises a rod fastened to the bottom of said vessel, said rod extending through the vessel and the head wall of the vessel, and said window comprises an at least partly transparent extension extending from the encapsulation, said rod protruding into said extension, an indicating member attached to the free end of said rod and at least a lower and an upper control mark associated with the transparent part of said extension.
4. A gas density indicator according to claim 3, wherein the upper edge of said window forms the upper control mark and the lower edge the lower control mark.
5. A gas density indicator according to claim 4, wherein said vessel has an internal stop by which the travel of the vessel bottom can be limited in the direction toward the vessel head wall.
6. A gas density indicator according to claim 1, 2 or 3, wherein said vessel has an internal stop by which the travel of the vessel bottom can be limited in the direction toward the vessel head wall.
7. A gas density indicator according to claim 2, and further including a permanent magnet fastened to the vessel bottom by which a magnetizable indicator located outside the encapsulation can be influenced without inertia, said control marks being associ-ated with said indicator.
8. A method for adjusting a gas density indicator for check-ing the density of an electro-negative gas in the encapsulation of an electric switching installation said indicator including a gas-tight vessel, which is at a predetermined internal pressure, disposed within the encapsulation; said vessel having a head wall, sides and a bottom, the position of said bottom variable in the longitudinal direction of the vessel in the event of density changes of the electro-negative gas, to indicate the density change; and an external stop extending below the vessel bottom at an adjustable distance comprising:
a) first evacuating the encapsulation with the vessel open;
b) limiting the expansion of the vessel occurring in the process by an external stop;
c) then sealing the vessel; and d) subsequently admitting the insulating gas into the encapsulation up to the desired pressure.
a) first evacuating the encapsulation with the vessel open;
b) limiting the expansion of the vessel occurring in the process by an external stop;
c) then sealing the vessel; and d) subsequently admitting the insulating gas into the encapsulation up to the desired pressure.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3142746.4 | 1981-10-28 | ||
| DE19813142746 DE3142746A1 (en) | 1981-10-28 | 1981-10-28 | GAS DENSITY INDICATOR |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1185455A true CA1185455A (en) | 1985-04-16 |
Family
ID=6145036
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000414253A Expired CA1185455A (en) | 1981-10-28 | 1982-10-27 | Gas density indicator |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0077981B1 (en) |
| JP (1) | JPS5883230A (en) |
| AT (1) | ATE14488T1 (en) |
| AU (1) | AU551860B2 (en) |
| BR (1) | BR8206266A (en) |
| CA (1) | CA1185455A (en) |
| DE (2) | DE3142746A1 (en) |
| ZA (1) | ZA827843B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL9002541A (en) * | 1990-11-22 | 1992-06-16 | Philips Nv | PRESSURE DIFFERENCE INDICATOR. |
| FR2732460B1 (en) * | 1995-03-31 | 1997-05-09 | Schneider Electric Sa | BISTABLE INDICATOR DEVICE FOR SIGNALING A GAS PRESSURE DROP IN A CHAMBER |
| FR2804210B1 (en) * | 2000-01-21 | 2003-08-01 | Alstom | METHOD AND DEVICE FOR CONTROLLING THE DENSITY OF A GAS INSIDE A SPEAKER USING A DUAL DENSITY SENSOR |
| DE102020204624A1 (en) | 2020-04-09 | 2021-10-14 | Siemens Aktiengesellschaft | Determining a fluid density in an electrical device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2000308A (en) * | 1930-06-25 | 1935-05-07 | Meaf Mach En Apparaten Fab Nv | Volume metering apparatus |
| CH413958A (en) * | 1964-10-23 | 1966-05-31 | Bbc Brown Boveri & Cie | Gas circulation system for compressed gas circuit breakers |
| NL7004555A (en) * | 1970-03-31 | 1971-10-04 | ||
| DE2711797C2 (en) * | 1977-03-18 | 1985-03-21 | Calor-Emag Elektrizitäts-Aktiengesellschaft, 4030 Ratingen | Device for determining the gas density |
| JPS5578231A (en) * | 1978-12-08 | 1980-06-12 | Toshiba Corp | Gas density measuring unit |
| DE2926260A1 (en) * | 1979-06-29 | 1981-01-08 | Bbc Brown Boveri & Cie | Gas density monitor for gas filled HV switchgear - has bourdon tube enclosed in gas to operate indicator |
-
1981
- 1981-10-28 DE DE19813142746 patent/DE3142746A1/en not_active Withdrawn
-
1982
- 1982-10-14 EP EP82109523A patent/EP0077981B1/en not_active Expired
- 1982-10-14 AT AT82109523T patent/ATE14488T1/en active
- 1982-10-14 DE DE8282109523T patent/DE3264932D1/en not_active Expired
- 1982-10-26 JP JP57188105A patent/JPS5883230A/en active Pending
- 1982-10-27 CA CA000414253A patent/CA1185455A/en not_active Expired
- 1982-10-27 BR BR8206266A patent/BR8206266A/en unknown
- 1982-10-27 AU AU89837/82A patent/AU551860B2/en not_active Expired - Fee Related
- 1982-10-27 ZA ZA827843A patent/ZA827843B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU8983782A (en) | 1984-05-03 |
| ZA827843B (en) | 1983-08-31 |
| EP0077981A2 (en) | 1983-05-04 |
| JPS5883230A (en) | 1983-05-19 |
| EP0077981B1 (en) | 1985-07-24 |
| DE3264932D1 (en) | 1985-08-29 |
| BR8206266A (en) | 1983-09-20 |
| AU551860B2 (en) | 1986-05-15 |
| ATE14488T1 (en) | 1985-08-15 |
| EP0077981A3 (en) | 1983-07-27 |
| DE3142746A1 (en) | 1983-05-05 |
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