• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    When measuring the density of gaseous media, particularly for monitoring insulating gases for switchgear, there is the problem of simpler and cheaper construction, because of the large number of monitoring devices required. The solution comprises one pressure-dependent and temperature-dependent electrical measuring transducer, whose signals are combined in such a way as to produce an output signal (UA) which is at least approximately proportional to the pressure and inversely proportional to the temperature. Thus it is possible to register a pressure-dependent and a temperature-dependent signal in separate measuring transducers and to superimpose them by multiplication or by forming the quotient. It is particularly advantageous to employ a piezoresistive pressure measuring transducer (MWP) which is connected to an electrical power source (QI) having an output variable (IB) inversely proportional to the temperature. <IMAGE>
    公开号:SU884587A3
    申请号:SU782631655
    申请日:1978-06-28
    公开日:1981-11-23
    发明作者:Ланц Отто
    申请人:Ббц Аг Браун Бовери Унд Ко (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to a device for measuring the density of gaseous media, for example, vapors, which can be carried out using mechanical pressure measuring instruments with additional consideration of the temperature of the medium as a relative measurement, or with additional consideration of constants (or gas constant) as a relative measurement. before
    Of particular importance is the measurement of density to control the pressure of insulating gases in switchgears, especially SF6 (sulfur hexafluoride). Numerous measurement and control points within the installation find practical application here J5, so that there is a need to simplify and cheapen the corresponding measuring devices 20 without loss of reliability and quality.
    A device for measuring the density of gaseous media containing pressure and temperature measuring transducers and a measuring circuit 25 with a controlled potentiometer [13 ·
    However, this device has a complex measuring circuit of the compensation type.
    The closest to the proposed technical essence and the achieved result is a device for measuring the density of gaseous media containing a direct current source, a bridge measuring circuit, in the opposite shoulders of which piezoresistive transducers, an output amplifier connected to the measuring diagonal of the bridge and a heat-sensitive element [2] are included.
    A disadvantage of the known device is the relative complexity of the measurement circuit. .
    The purpose of the invention is to simplify the device.
    This goal is achieved by the fact that in the proposed device for measuring the density of gaseous media containing a direct current source, a bridge measuring circuit, in the opposite shoulders of which are included piezoresistive pressure transducers, an output amplifier connected to the measuring diagonal of the bridge, and a temperature-sensitive element, a compensation element is introduced an amplifier connected between a DC power source and the bridge diagonal, and a heat-sensitive element having a negative temperature * resistance coefficient is included in the DC source circuit.
    The drawing shows a schematic diagram of the proposed device.
    The device contains a direct current source 1, a bridge measuring circuit 2, on the opposite shoulders of which are piezoresistive pressure transducers 8 y and 8χ 2 Η an output amplifier 3 connected to the measuring diagonal of the bridge 2. Between the direct current source 1 and the diagonal of the bridge 2 power supply. amplifier 4. A temperature-sensitive element 5 having a negative temperature coefficient of resistance is included in the DC source circuit. In a particular embodiment, the heat-sensitive element 5 is made in the form of a diode.
    The device operates as follows.
    Piezoresistive pressure transmitters 8- ^ and Ηχ are subjected to the pressure of the medium being measured, while a voltage U ^ arises in the measuring diagonal of the bridge 2 ', proportional to the pressure and supply current 1 ^. The latter is converted at the weekend. amplifier 3 into a voltage signal of the corresponding power level.
    The inverse temperature dependence of the measured voltage is achieved by, firstly, the Ig supply current and, secondly, by means of a compensation amplifier 4 with an input voltage that is inverse to temperature. The input circuit of the compensation amplifier 4 forms an imbalance between the voltage drop proportional to the current 1 ^ at the resistance p £ set for the purpose of adjustment and the input voltage Ug, which depends on the temperature pt, and after amplification this imbalance is set close to zero using an appropriately set supply current. With the balanced state of the compensation amplifier 4, the current I g is proportional to the input voltage U ^, which depends on the temperature. Therefore, the compensation amplifier 4 acts as a current-voltage converter 10.
    The input voltage, depending on the temperature, is generated using a constant current source 1 as a voltage drop on the temperature-sensitive element 15 5, similar to the corresponding semiconductor diode having a characteristic opposite to the temperature. Usually, a potentiometer is introduced for this purpose, which serves to correct temperature coefficients. This is obtained using simple means. comparatively accurate inverse temperature dependence with high stability over time (weak drift25 fom).
    权利要求:
    Claims (2)
    [1]
    a pavement measuring circuit, on the opposite shoulders of which piezo-resistive pressure transducers are connected, an output amplifier connected to the measuring diagonal of the bridge, and a temperature-sensitive element, is introduced a compensation amplifier connected between the direct current source and the diagonal of the bridge power supply, and a temperature-sensitive element having a negative temperature resistance factor, included in the circuit of the DC source. The drawing shows a schematic diagram of the proposed device. The device contains a DC source 1, the MOCTOByto measuring circuit 2, on the opposite shoulders of which are connected piezoresistive pressure transducers Rj and an output amplifier 3 connected to the meters of the diagonal of the bridge 2. MecDu by a source of direct current 1 and dia. The power supply of bridge 2 is switched on a compensation amplifier 4. A temperature sensor 5, having a negative temperature coefficient of resistance, is included in the circuit of a direct current source. In a particular embodiment, temperature sensors 1) element 5 is made in the input diode. The device operates as follows: Piezoresistive pressure transducers R and H are subjected to deformation of the VIA pressure of the measured medium, and a voltage appears in the measuring diagonal of bridge 2 and, d proportional to the pressure and current of power 1, the last is converted to output. amplifier 3 to a voltage signal of appropriate power level. The inverse temperature dependence of the measured voltage Udd is achieved by, first, the supply current Ig and, secondly, by using the compensation amplifier 4 with the input voltage, inverse, temperature. The input circuit of the compensation amplifier 4 forms an unbalance between the voltage drop proportional to the current 1 ,, on the resistance p set for the purpose of alignment and the input voltage Up, depending on the temperature QT, and after amplifying this unbalance is set to zero with the appropriately set supply current Ig. In the balanced state of the compensation A-amplifier A, the current I g is proportional to the input voltage Ljj, depending on the temperature. Therefore, the compensation amplifier 4 acts as a current-to-voltage converter. The input voltage, depending on the temperature, is formed by the DC power source 1 as a voltage drop across the temperature sensing element 5, similar to the corresponding semiconductor diode, which has a characteristic opposite to the temperature. Usually, its potentiometer Pf is inserted for this purpose; it is a case of S1; it is used to correct temperature coefficients. It is obtained by simple means. relatively accurate temperature inverse relationship with high stability over time (weak drift). The invention of the device for measuring the density of gaseous media, containing a DC source, a pavement measuring circuit, on the opposite arms of which are included piezoresistive pressure transducers, an output amplifier connected to the bridge diagonal, and a temperature-sensitive element that differs from in order to simplify the device, a compensation amplifier was inserted into it, connected between a DC source and the diagonal of the power supply of the bridge, and the temperature-sensitive element I have negative negative temperature coefficient of resistance, is included in the circuit of a source of direct current. Sources of information taken into account in the examination 1. US patent number 3162043, ШШ 73-27, 1968.
    [2]
    2.IJiJrgen Bretschi HalbleiterDebmingsmestreifen - Eine ubersicht, Teil ll Archiv fUr teehnisches Messen ,, (April. 1974), c. 73 (prototype).
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    同族专利:
    公开号 | 公开日
    JPS6147371B2|1986-10-18|
    JPS5414270A|1979-02-02|
    CH616743A5|1980-04-15|
    DE2736946A1|1979-01-18|
    FR2396283A1|1979-01-26|
    NL7806940A|1979-01-03|
    引用文献:
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    RU2531043C1|2013-07-26|2014-10-20|Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Тверской государственный технический университет"|Laboratory analyser of gas density|US3162043A|1960-08-12|1964-12-22|Giannini Controls Corp|Compensated air density computer|
    FR1366909A|1963-06-05|1964-07-17|Bagneux S A Atel Const|Device for calculating air density and its application to helicopters|
    FR1467112A|1965-12-08|1967-01-27|Thomson Houston Comp Francaise|Improvements to methods and devices for determining the density of a gas|
    US3862568A|1972-06-22|1975-01-28|Itt|Method of and apparatus for producing fluid gravity and density analogs and flowmeters incorporating gravitometers|
    AT331539B|1972-10-25|1976-08-25|Kratky Otto Dr Dr E H|DEVICE FOR MEASURING DENSITY|
    US3967188A|1973-05-24|1976-06-29|Bell & Howell Company|Temperature compensation circuit for sensor of physical variables such as temperature and pressure|DE2914037C2|1979-04-06|1983-12-08|Siemens AG, 1000 Berlin und 8000 München|Device for rendering ineffective deviations in the output voltage of a pressure transducer in magnetic tape recorders caused by temperature fluctuations|
    JPS5686331A|1979-12-17|1981-07-14|Toshiba Corp|Measuring device of gas density|
    JPH0425488B2|1983-04-06|1992-05-01|Hitachi Ltd|
    JPS63206634A|1987-02-24|1988-08-25|Toshiba Corp|Gas density sensor|
    FR2872572B1|2004-06-30|2006-09-22|Commissariat Energie Atomique|TESTING THE SEALING OF MEMS OR SMALL ENCAPSULATED COMPONENTS|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    CH809777A|CH616743A5|1977-07-01|1977-07-01|Device for measuring the density of gaseous media.|
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