CN1155073A - Low-temp. liquid-level meter - Google Patents
Low-temp. liquid-level meter Download PDFInfo
- Publication number
- CN1155073A CN1155073A CN 96118731 CN96118731A CN1155073A CN 1155073 A CN1155073 A CN 1155073A CN 96118731 CN96118731 CN 96118731 CN 96118731 A CN96118731 A CN 96118731A CN 1155073 A CN1155073 A CN 1155073A
- Authority
- CN
- China
- Prior art keywords
- diode
- liquid level
- liquid
- low
- temp
- 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.)
- Pending
Links
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Abstract
The present invention relates to a low-temp. level-meter capable of accurately monitoring and controlling liquid level change in low-temp. container, including a positioning board, at least two seriesconnected germanium diode groups are placed on the positioning board, series-connected with a constant current source, and at the same time are connected in parallel with a digital voltmeter. Said invented level-meter possesses the advantages of high resolution, good reproducibility, small heat loss, simple structure, convenient application and low cost.
Description
The present invention specially is in a kind of high-resolution low temperature liquid level gauge that the level change of liquid is developed among the low-temperature (low temperature) vessel for accurately monitoring and controlling.
At present, though it is a lot of to be used for measuring the method for cryogenic liquid liquid level, wherein resistance-type and capacitance level gauge have and can export continuous voltage or capacitance signal, are used for measuring, observation and control liquid level.Shortcomings such as but all there is poor sensitivity in they, and resolution is low, and serviceable life is short can not satisfy scientific research and industrial active demand.
Purpose of the present invention is intended to overcome the existing existing shortcoming of liquid level gauge, according to germanium diode when steady current passes through therein, its output voltage in cryogen vapour-liquid two-phase has characteristics such as evident difference, make a kind of novel low temperature liquid level gauge, have the resolution height, repdocutbility is good, thermal losses is little, advantage such as simple in structure, easy to use, cheap.
The present invention is made up of germanium diode liquid level sensor, milliampere level continuous current control circuit and digital voltmeter (or numeral shows multimeter).
Fig. 1 is a structure principle chart of the present invention.
Fig. 2 is a circuit diagram of the present invention.
Below in conjunction with accompanying drawing structural principle of the present invention and principle of work are done detailed explanation.
With reference to accompanying drawing, the present invention includes a location-plate (5), dispose at least two diode in series groups (1) on the location-plate, diode group (1) is connected in series mutually with a constant current source (2), and a while and a digital voltmeter (3) are in parallel.Most preferred embodiment of the present invention is a formed-point-contact diode, and said location-plate (5) can be two flat boards or cylindrical wall or the straight-bar that intersects.The range of current of constant current source (2) is 40～100mA.In addition, among the figure, (4) are the baffle plates that is configured in outside the diode group (1), stop the boiling bubble directly to contact with diode group (1).
During use, with location-plate (5) and on diode group (1) vertically be placed in the container, when the liquid level change in the container, part diode emersion liquid level, be in the gas phase, because the coefficient of heat transfer of gas is less, the coefficient of heat transfer of liquid is bigger, cause the diode in the gas phase higher, so the diode forward output voltage in the gas phase is lower because of the temperature rise that self-heating effect produces.If the diode of emersion liquid level is many more, then total output voltage of diode group is just low more, according to the size of total output voltage, just can judge which diode emersion liquid level, thereby can measure the height of liquid level thus.
Principle of work of the present invention is: experimental studies have found that, diode (1) is passed to a certain size working current (this working current is provided by a constant current source (2)), diode itself can produce a certain size self-heating effect, and the positive pole of diode will be exported a certain size forward voltage.The big I of forward voltage is measured by the digital voltmeter (3) that is connected in parallel in the circuit.Along with the difference of the temperature of the residing fluid of diode, the corresponding variation also takes place in the size of forward voltage that diode is exported thereupon.Utilize this temperature characterisitic of diode, can make the diode temperature meter, be used for accurately measuring the temperature of fluid, this fact is confirmed by domestic and international many researchers.
But, utilize this temperature characterisitic of diode to be developed into the low temperature liquid level gauge, to reach the purpose of accurately monitoring and control the low temperature liquid level, but still nobody carries out this research.In fact, because the transmission speed of heat in liquid phase is fast more than the transmission speed in gas phase.Thereby the temperature rise of diode in liquid phase is littler than the temperature rise in gas phase, and the forward output voltage of diode becomes the negative effect relation with the temperature rise of himself.Like this, the forward output voltage of diode in liquid phase is just little than its output voltage in vapour phase.Therefore, we utilize diode to cause the variation of forward output voltage because of the difference of heat transfer property in the vapour-liquid two-phase, just can reach measuring liquid level purpose just.If settle a control gear in the line, just can control and keep a certain liquid level very easily automatically.Experimental study shows that the variation of the forward output voltage of germanium diode in cryogen vapour-liquid two-phase is fairly obvious.Forward output voltage difference in the gentle nitrogen of liquid nitrogen reaches about 0.2V, is 5～10 times of resistance-type liquid level meter resolution.Thereby the low temperature liquid level gauge that adopts germanium diode to be developed into has the measuring accuracy height, installation of resolution height, stable and reliable for performance, liquid level, characteristics such as easy to use, can satisfy scientific research and demand of practical production in the low temperature field well.
In order to guarantee the operate as normal of germanium diode, make the liquid level meter remain high resolving power, accurately measure and control the purpose of liquid level: (1) must guarantee stable, the reliable performance of constant current control circuit included among the present invention.Because germanium diode only under the working current of stable size, produces a certain size self-heating effect, the forward voltage values that diode is exported through cryogen vapour-liquid two-phase interface the time has evident difference.Otherwise, if working current is too small, for example, when working current is 400 microamperes, only 10 millivolts of the forward voltage differences that germanium diode is exported in the gentle nitrogen of liquid nitrogen, resolution is very low, can't carry out accurate level gauging at all.Certainly, when working current was excessive, the self-heating effect of diode itself will be excessive, burns diode easily or shorten its serviceable life.Therefore working current can not be too small can not be excessive.Recommended current of the present invention is 40～100mA.(2) volume of diode (1) and the big young pathbreaker of thermal inertia directly influence the precision of level gauging, for this reason, the present invention selects a contact germanium diode for use, and it is to be pressed on the smooth wafer by a very thin tinsel to constitute, tinsel is anodal, and wafer is a negative pole.This diode is sealed in the glass shell, and volume is little, and thermal inertia is little.When diode passes to steady current, tangible self-heating effect is arranged.When (3) using the present invention to measure the liquid level of the cryogen of seething with excitement, the outside of liquid level meter need add a baffle plate (5), this is the impact that is used for blocking because of the stream-liquid two-phase flow body of the fierce boiling of heating, make germanium diode be in comparatively tranquil liquid (liquid nitrogen) district, so that measure and control the liquid level of cryogen exactly.Otherwise the germanium diode liquid level gauge can't operate as normal.(4) number of the germanium diode in the germanium diode group circuit must be limited in 1～7 scope, to guarantee the operate as normal of constant current source.(5) if the liquid level scope of required control is bigger, in the time only can not satisfying the needs of liquid level gauging with a germanium diode liquid level gauge, then can be together adjacent with two or three germanium diode liquid level gauges, get final product with several constant current sources controls respectively.
The present invention is applicable to cryogen, also applicable to middle temperature and normal temperature fluid.
Claims (4)
1. the low temperature liquid level gauge comprises a location-plate (5), and feature of the present invention is, disposes the germanium diode group (1) of at least two series connection on the location-plate (5), and diode group (1) is connected in series mutually with a constant current source (2), simultaneously and a digital voltmeter (3) be in parallel.
2. low temperature liquid level gauge according to claim 1 is characterized in that, said diode is a formed-point-contact diode.
3. low temperature liquid level gauge according to claim 1 is characterized in that, configuration one baffle plate (4) outside said diode group (1).
4. according to claim 1,3 described low temperature liquid level gauges, it is characterized in that the range of current of said constant current source (2) is 40～100mA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96118731 CN1155073A (en) | 1996-07-24 | 1996-07-24 | Low-temp. liquid-level meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96118731 CN1155073A (en) | 1996-07-24 | 1996-07-24 | Low-temp. liquid-level meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1155073A true CN1155073A (en) | 1997-07-23 |
Family
ID=5125298
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96118731 Pending CN1155073A (en) | 1996-07-24 | 1996-07-24 | Low-temp. liquid-level meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1155073A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1831493B (en) * | 2006-04-10 | 2010-05-12 | 中国科学院电工研究所 | Liquid nitrogen liquid level measuring device for high voltage surperconducting power equipment |
| CN102243090A (en) * | 2011-04-02 | 2011-11-16 | 长沙开元仪器股份有限公司 | Water level detector |
| CN102426464A (en) * | 2011-09-30 | 2012-04-25 | 中国科学院电工研究所 | Automatic liquid supplementation device of high-temperature superconducting transformer |
| CN103630194A (en) * | 2012-08-28 | 2014-03-12 | 谢安军 | Liquid level measuring instrument |
| CN103630193A (en) * | 2012-08-24 | 2014-03-12 | 谢安军 | Liquid level measuring instrument |
-
1996
- 1996-07-24 CN CN 96118731 patent/CN1155073A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1831493B (en) * | 2006-04-10 | 2010-05-12 | 中国科学院电工研究所 | Liquid nitrogen liquid level measuring device for high voltage surperconducting power equipment |
| CN102243090A (en) * | 2011-04-02 | 2011-11-16 | 长沙开元仪器股份有限公司 | Water level detector |
| CN102426464A (en) * | 2011-09-30 | 2012-04-25 | 中国科学院电工研究所 | Automatic liquid supplementation device of high-temperature superconducting transformer |
| CN103630193A (en) * | 2012-08-24 | 2014-03-12 | 谢安军 | Liquid level measuring instrument |
| CN103630194A (en) * | 2012-08-28 | 2014-03-12 | 谢安军 | Liquid level measuring instrument |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102997974B (en) | Adaptive capacitance liquid level meter | |
| CN205879394U (en) | Temperature measuring circuit and adopt high accuracy temperature measuring device of this circuit | |
| CN101551264B (en) | Capacitance electronic type fuel sensor | |
| CN1155073A (en) | Low-temp. liquid-level meter | |
| CN201215505Y (en) | Digital weighing controller | |
| CN202404464U (en) | Temperature measuring and controlling device | |
| CN2278206Y (en) | Gravity type liquid level gauge | |
| CN211576290U (en) | Intelligent monitoring device for oil quantity of insulating oil | |
| CN203535468U (en) | Detector for temperature and humidity controller | |
| CN210400375U (en) | Slope measuring device based on liquid level sensor | |
| CN102162747A (en) | Signal processing circuit for photoelectric sensor | |
| CN206832304U (en) | A kind of quality formula flow internet of things sensors | |
| SU1627849A1 (en) | Level measuring gauge | |
| CN201508209U (en) | Capacitance electronic fuel sensor | |
| CN209802497U (en) | High-precision electronic balance | |
| CN219641042U (en) | Paddy field water level monitoring device | |
| PRENGLE Jr et al. | Thermodynamics of solutions: new equipment for measuring heats of solution data for five systems | |
| CN103488164A (en) | Detector for temperature and humidity controller | |
| JPS5619438A (en) | Detector for specific gravity of battery electrolyte | |
| CN212540522U (en) | Device for measuring current magnitude by using current thermal effect | |
| RU206142U1 (en) | Optoelectronic device for measuring the density of liquids with fiber optic communication lines | |
| CN207985144U (en) | A kind of drauht monitoring system based on wireless transmission | |
| CN116592963A (en) | Device and method for measuring wine damage in white wine storage process | |
| CN2060884U (en) | Multi-function mf-10 type water analysing instrument | |
| RU39568U1 (en) | FUEL VOLUME METER |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C01 | Deemed withdrawal of patent application (patent law 1993) | ||
| WD01 | Invention patent application deemed withdrawn after publication |