JPH0362205B2 - - Google Patents
Info
- Publication number
- JPH0362205B2 JPH0362205B2 JP60013431A JP1343185A JPH0362205B2 JP H0362205 B2 JPH0362205 B2 JP H0362205B2 JP 60013431 A JP60013431 A JP 60013431A JP 1343185 A JP1343185 A JP 1343185A JP H0362205 B2 JPH0362205 B2 JP H0362205B2
- Authority
- JP
- Japan
- Prior art keywords
- electroacoustic transducer
- temperature
- signal
- volume
- heating
- 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 - Lifetime
Links
- 238000010438 heat treatment Methods 0.000 claims description 19
- 238000001514 detection method Methods 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 230000010355 oscillation Effects 0.000 description 10
- 239000007788 liquid Substances 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 238000012935 Averaging Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000002828 fuel tank Substances 0.000 description 2
- 230000005611 electricity Effects 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は自動車用の燃料タンクのような密閉容
器内の容積を測定する装置に関し、特にその容器
内に音響信号を供給して容積を測定する音響式容
積測定装置に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for measuring the volume inside a closed container such as a fuel tank for an automobile, and particularly to a device for measuring the volume by supplying an acoustic signal into the container. The present invention relates to an acoustic volume measuring device.
自動車用燃料タンクの燃料計などの被測定容器
内に音響信号を与え、この音響信号を与えるため
の電気音響変換器の定数と被測定部容積とで決ま
る共振周波数から被測定容器内の容積を測定し、
そこから容器内に存在する燃料などを知る装置が
提案されている。
An acoustic signal is applied to the inside of the container to be measured, such as a fuel meter for an automobile fuel tank. measure,
A device has been proposed that uses this information to determine the fuel and other information present in the container.
かかる装置としては従来第２図に示すように構
成されているものがある。この第２図において被
測定密閉容器１１は上面に開口１６が形成され、
この開口１６を塞ぐように電気音響変換器１７が
密閉容器１１に取付けられている。電気音響変換
器１７は例えば可動線輪（ムービングコイル）型
スピーカのようなものを用いることができ、その
コーン振動板周縁部が開口１６の内周縁部と接続
されて開口１６が塞がれている。従つてこの電気
音響変換器１７を交流信号で駆動することによつ
て密閉容器１１内の内容積を変化させることがで
きる。つまり、密閉容器１１内に液体１４が充填
されており、従つて密閉容器１１内の容積、即ち
液体１４が満たされている以外の空間部分の容積
Ｖを測定することによつて液体１４の体積を測定
することができる。 Conventionally, such a device is constructed as shown in FIG. In FIG. 2, the sealed container 11 to be measured has an opening 16 formed on the top surface.
An electroacoustic transducer 17 is attached to the closed container 11 so as to close this opening 16. The electroacoustic transducer 17 can be, for example, a moving coil type speaker, and the periphery of the cone diaphragm is connected to the inner periphery of the opening 16 so that the opening 16 is closed. There is. Therefore, by driving this electroacoustic transducer 17 with an alternating current signal, the internal volume within the closed container 11 can be changed. That is, the liquid 14 is filled in the closed container 11, and the volume of the liquid 14 is determined by measuring the volume inside the closed container 11, that is, the volume V of the space other than the one filled with the liquid 14. can be measured.
そしてこの電気音響変換器１７に対してほぼ連
続した周波数の電気信号を供給し駆動させる。電
気信号を供給する手段としては、まず掃引信号発
生器１８により第３図Ａに示す鋸歯状波電圧の掃
引信号１９が発生し、この掃引信号１９を制御電
圧とする電圧制御発振器（VCO）２１に供給し
てVCO２１より第３図Ｂに示すように時間に対
して周波数が高くなることを繰り返す発振出力が
得られる。この発振出力は増幅器２２を通じて電
気音響変換器１７に供給されこれが駆動される。 Then, an electrical signal with a substantially continuous frequency is supplied to the electroacoustic transducer 17 to drive it. As a means for supplying an electric signal, first, a sweep signal generator 18 generates a sawtooth voltage sweep signal 19 shown in FIG. As shown in FIG. 3B, an oscillation output whose frequency repeatedly increases with time is obtained from the VCO 21. This oscillation output is supplied to the electroacoustic transducer 17 through the amplifier 22 to drive it.
この密閉容器１１内の容積Ｖと電気音響変換器
１７の定数とによつて決まる共振周波数を検出す
るために、電気音響変換器１７の入力側に全波整
流器２３が接続され、この全波整流出力をピーク
検出回路２４によりピーク値を検出する。 In order to detect the resonant frequency determined by the volume V inside this sealed container 11 and the constant of the electroacoustic transducer 17, a full-wave rectifier 23 is connected to the input side of the electroacoustic transducer 17, and this full-wave rectifier 23 is connected to the input side of the electroacoustic transducer 17. A peak value of the output is detected by a peak detection circuit 24.
電気音響変換器１７に対する駆動周波数が、こ
の電気音響変換器１７の定数と、容器１１の容積
Ｖとで決まる共振周波数mに一致すると、音響
インピーダンスが最大となり電気音響変換器１７
の入力側の信号振幅が著しく大きくなる。従つて
第３図Ｃに示すように、電気音響変換器１７の入
力側における信号レベルは駆動信号周波数が共
振周波数mになると、ピーク２５が生じる。掃
引信号１９は第３図Ａに示すように電圧E1〜E2
の範囲を鋸歯状波的に変化し、これに伴つて発振
周波数は1〜2の期間を鋸歯状波的に変化する
が、その周波数が前記共振周波数mになると、
電気音響変換器１７の入力側における信号の振幅
は著しく大きくなり、ピーク２５が現れる。従つ
てピーク検出器２４の出力は第３図Ｄに示すよう
にピーク２５に対応した部分でパルス２６が発生
する。このパルス２６が得られた時の掃引信号１
９のレベルEmを標本化保持回路２７で第３図Ｅ
に示すように標本化保持する。このレベルＥは
VCO２１の共振信号発生器mと対応しており、
標本化保持電圧EmをＡ／Ｄ変換器２８によつて
デジタル信号に変換し、表示器２９に表示する。 When the driving frequency for the electroacoustic transducer 17 matches the resonance frequency m determined by the constant of the electroacoustic transducer 17 and the volume V of the container 11, the acoustic impedance becomes maximum and the electroacoustic transducer 17
The signal amplitude on the input side becomes significantly large. Therefore, as shown in FIG. 3C, the signal level at the input side of the electroacoustic transducer 17 has a peak 25 when the drive signal frequency reaches the resonance frequency m. The sweep signal 19 is a voltage E 1 -E 2 as shown in FIG. 3A.
Accordingly, the oscillation frequency changes in a sawtooth manner over a period of 1 to 2 , but when the frequency reaches the resonance frequency m,
The amplitude of the signal at the input side of the electroacoustic transducer 17 becomes significantly larger and a peak 25 appears. Therefore, in the output of the peak detector 24, a pulse 26 is generated at a portion corresponding to the peak 25 as shown in FIG. 3D. Sweep signal 1 when this pulse 26 is obtained
The level Em of 9 is sampled and held by the circuit 27 as shown in Fig. 3E.
Sample and hold as shown in . This level E
It corresponds to the resonance signal generator m of VCO21,
The sampled holding voltage Em is converted into a digital signal by the A/D converter 28 and displayed on the display 29.
この場合、共振周波数mは上述のとおり容器
１１の内容積Ｖと、変換器１７の定数とによつて
決まり、変換器１７の定数は一定であるから、容
積Ｖと対応する。従つて検出した周波数mと対
応する電圧Emと容器Ｖとを予め較正しておくこ
とにより、表示器２９に容器１１の内容積Ｖ、即
ち液体１４の残量を表示することができる。 In this case, the resonance frequency m is determined by the internal volume V of the container 11 and the constant of the converter 17 as described above, and since the constant of the converter 17 is constant, it corresponds to the volume V. Therefore, by calibrating the voltage Em corresponding to the detected frequency m and the container V in advance, the internal volume V of the container 11, that is, the remaining amount of the liquid 14 can be displayed on the display 29.
尚、ピーク２５におけるVCOの発振周波数m
と密閉容器１１内の容積Ｖとが直線的関係となる
ように補正回路３０を標本化保持回路２７とＡ／
Ｄ変換器２８との間に設けてもよい。 Furthermore, the oscillation frequency m of the VCO at peak 25
The correction circuit 30 is connected to the sampling holding circuit 27 and the A/
It may also be provided between the D converter 28 and the D converter 28.
（発明が解決しようとする問題点）
かかる従来の音響式容積測定装置では、電気音
響変換器自体の温度特性が特に低温時において悪
く、検出されるピーク時の発振周波数が変動して
しまう。(Problems to be Solved by the Invention) In such a conventional acoustic volume measuring device, the temperature characteristics of the electroacoustic transducer itself are poor especially at low temperatures, and the detected peak oscillation frequency fluctuates.
即ち、温度変化によつて例えば可動線輪型電気
音響変換器では、この可動線輪の直流抵抗値が変
化し、共振周波数が変動してしまい、被測定容器
の容積との関係がくずれてしまう。 That is, in a movable wire type electroacoustic transducer, for example, due to temperature changes, the DC resistance value of the movable wire changes, the resonance frequency fluctuates, and the relationship with the volume of the container to be measured breaks down. .
また、蒸気圧などの関係によりガソリンなどの
液体が電気音響変換器の可動部（コーン振動板）
に付着した場合も、振動板の質量が変化し、同様
にピーク時の発振周波数が変動して安定した容量
測定が困難となる。 Also, due to vapor pressure, etc., liquids such as gasoline may cause the moving parts of the electroacoustic transducer (cone diaphragm) to
If it adheres to the diaphragm, the mass of the diaphragm changes, and the oscillation frequency at the peak also fluctuates, making stable capacitance measurement difficult.
よつて本発明は、上述の従来の問題点に鑑み、
電気音響変換器自身の温度特性を安定に維持し
て、密閉容器の容積をより正確に測定できるよう
にした音響式容積測定装置を提供することを目的
としている。 Therefore, in view of the above-mentioned conventional problems, the present invention has been made to
It is an object of the present invention to provide an acoustic volume measuring device that can more accurately measure the volume of a closed container by stably maintaining the temperature characteristics of the electroacoustic transducer itself.
上記目的を達成するため本発明により成された
音響式容積測定装置は、密閉容器の開口を塞ぐよ
うに設けられ、駆動されることによつて前記密閉
容器の容積を変化させる電気音響変換器と、該電
気音響変換器を連続的に周波数が変化する電気信
号で駆動する駆動手段と、前記密閉容器の容積と
前記電気音響変換器の定数とによつて決まる共振
周波数を検出する検出手段とを備え、前記検出手
段によつて検出した共振周波数に基づいて前記密
閉容器の容積を測定する音響式容積測定装置であ
つて、前記駆動手段が前記共振周波数より十分に
低い周波数の電気信号により前記電気音響変換器
を駆動しているとき、前記電気信号を直流に変換
して前記電気音響変換器の温度に応じた大きさの
直流信号を出力する直流変換手段と、該直流変換
手段が出力する直流信号と所定の温度に対応する
基準値とを比較するコンパレータと、該コンパレ
ータによる比較結果により動作する温度制御手段
と、該温度制御手段によつて制御され、前記電気
音響変換器の可動部を加熱し、加熱部の温度を一
定に保つ加熱手段とを備え、前記温度制御手段
が、前記直流変換手段からの直流信号に対応する
温度が基準値によつて設定される温度より低いと
き前記加熱手段による前記電気音響変換器の加熱
を行わせ、高いとき前記加熱手段による前記電気
音響変換器の加熱を停止させることを特徴として
いる。
In order to achieve the above object, an acoustic volume measuring device according to the present invention includes an electroacoustic transducer that is provided to close the opening of a closed container and changes the volume of the closed container by being driven. , a driving means for driving the electroacoustic transducer with an electric signal whose frequency continuously changes, and a detection means for detecting a resonant frequency determined by the volume of the sealed container and a constant of the electroacoustic transducer. an acoustic volume measuring device for measuring the volume of the sealed container based on the resonant frequency detected by the detecting means, wherein the driving means detects the electric current by an electric signal having a frequency sufficiently lower than the resonant frequency. DC converting means for converting the electrical signal into direct current and outputting a direct current signal having a magnitude corresponding to the temperature of the electroacoustic transducer when the acoustic transducer is being driven; and a direct current output by the direct current converting means. a comparator that compares the signal with a reference value corresponding to a predetermined temperature; a temperature control means that operates according to the comparison result of the comparator; and a temperature control means that is controlled by the temperature control means and heats the movable part of the electroacoustic transducer. and heating means for keeping the temperature of the heating section constant, and the temperature control means controls the heating means when the temperature corresponding to the DC signal from the DC conversion means is lower than the temperature set by the reference value. The electroacoustic transducer is heated by the heating means, and when the temperature is high, the heating of the electroacoustic transducer by the heating means is stopped.
上記構成において、駆動手段が共振周波数より
十分に低い周波数の電気信号により電気音響変換
器を駆動しているときの電気信号を直流変換手段
が直流に変換して出力する直流信号によつて、電
気音響変換器の温度を検出し、この検知した温度
と所定の温度に対応する基準値とをコンパレータ
が比較し、この比較の結果、検知した温度が基準
値によつて設定される温度より低いとき、温度制
御手段が加熱手段に電気音響変換器の可動部を加
熱させ、高いとき温度制御手段が加熱手段による
電気音響変換器の可動部の加熱を停止させるよう
にしているので、電気音響変換器の温度が基準値
によつて決定される所定の温度に保持されるよう
になり、温度変化によつて電気音響変換器の定数
が変化することがなくなる。
In the above configuration, when the driving means is driving the electroacoustic transducer with an electric signal having a frequency sufficiently lower than the resonant frequency, the DC converting means converts the electric signal into DC and outputs the DC signal to generate electricity. The temperature of the acoustic transducer is detected, and a comparator compares the detected temperature with a reference value corresponding to a predetermined temperature, and as a result of this comparison, when the detected temperature is lower than the temperature set by the reference value. , the temperature control means causes the heating means to heat the movable part of the electroacoustic transducer, and when the temperature is high, the temperature control means stops the heating of the movable part of the electroacoustic transducer by the heating means, so that the electroacoustic transducer The temperature of the electroacoustic transducer is maintained at a predetermined temperature determined by the reference value, and the constant of the electroacoustic transducer does not change due to temperature changes.
また、電気音響変換器の温度を、共振周波数よ
り低い周波数の電気信号を直流に変換することに
よつて間接的に検出しているので、温度検知手段
を別途設ける必要がなくなつている。 Furthermore, since the temperature of the electroacoustic transducer is indirectly detected by converting an electrical signal with a frequency lower than the resonance frequency into direct current, there is no longer a need to provide a separate temperature detection means.
以下本発明の実施例を図面と共に説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図に示す実施例において、第２図と同一部
分は同一符号を付記しており、その動作について
は第２図と同様なので省略する。 In the embodiment shown in FIG. 1, the same parts as in FIG. 2 are given the same reference numerals, and since their operations are the same as in FIG. 2, their explanation will be omitted.
掃引信号発生器１８から発生する第３図Ａに示
す鋸歯状波によつてVCO２１が第３図Ｂのよう
に発振する。この周波数が鋸歯状波的に変化する
発振信号を増幅器２２に入力すると共に、増幅器
２２を通してAC／DC変換器３１に入力する。
AC／DC変換器３１では全波整流器２３及びピー
ク検出回路２４と同様にVCO２１の交流発振信
号をエンベロープ検波し、第３図Ｄに示す直流信
号に変換する。 The VCO 21 oscillates as shown in FIG. 3B by the sawtooth wave shown in FIG. 3A generated by the sweep signal generator 18. This oscillation signal whose frequency changes like a sawtooth wave is input to the amplifier 22 and, through the amplifier 22, to the AC/DC converter 31.
The AC/DC converter 31 performs envelope detection on the AC oscillation signal of the VCO 21 in the same way as the full-wave rectifier 23 and the peak detection circuit 24, and converts it into a DC signal as shown in FIG. 3D.
従つて、AC／DC変換器３１を別途設けずにピ
ーク検出回路２４の出力信号を利用してもよい。 Therefore, the output signal of the peak detection circuit 24 may be used without separately providing the AC/DC converter 31.
この直流変換された信号を平均化回路３２に供
給し、直流信号を数回繰り返して読み出し、その
平均値を算出する。算出された平均値をコンパレ
ータ３３により予め設定した基準値と比較し、こ
の比較結果により温度制御回路３４を制御する。
温度制御回路３４では電気音響変換器１７のコー
ン振動板３６の周縁固定部に取付けた加熱装置３
５の動作を制御する。 This DC-converted signal is supplied to the averaging circuit 32, the DC signal is read out several times, and the average value is calculated. The calculated average value is compared with a preset reference value by a comparator 33, and the temperature control circuit 34 is controlled based on the comparison result.
The temperature control circuit 34 includes a heating device 3 attached to a peripheral fixed portion of the cone diaphragm 36 of the electroacoustic transducer 17.
Controls the operation of 5.
次に上記の構成において、動作について説明す
る。 Next, the operation of the above configuration will be explained.
第３図Ｄに示す共振周波数mを持つ直流信号
において、共振周波数mよりも十分に低い周波
数sにおける電圧レベルVlevelは、電気音響変換
器１７に直流信号を印加したときの電圧と同様で
ある。従つて、この電圧レベルVlevelを増幅し
た電圧Vampの温度特性は第４図Ａに示すように
なる。即ち、電気音響変換器１７の可動線輪は、
温度が上昇するとそれにほぼ比例して抵抗値が大
きくなる。従つて、VCO２１から出力される発
振信号のうち、共振周波数mより十分に低い周
波数sにおける直流変換後の電圧Vampは、温度
に対してほぼ比例関係となつている。 In the DC signal having the resonant frequency m shown in FIG. Therefore, the temperature characteristics of the voltage Vamp obtained by amplifying this voltage level Vlevel are as shown in FIG. 4A. That is, the movable ring of the electroacoustic transducer 17 is
As the temperature rises, the resistance value increases almost proportionally. Therefore, among the oscillation signals output from the VCO 21, the DC-converted voltage Vamp at a frequency s sufficiently lower than the resonance frequency m is approximately proportional to the temperature.
そこでこの低周波数sにおける直流電圧を検出
し、第４図Ｂに示すようにこの直流電圧Vampと
基準電圧Vrefとをコンパレータ３３により比較
して、比較結果を温度制御回路３４に加える加熱
装置３５を制御することにより図面に示すような
温度制御を行う。即ち、電圧Vampが基準電圧
Vrefより低い状態では加熱装置３５を作動させ
て電気音響変換器１７を加熱し、基準電圧Vref
より高くなれば加熱装置３５を非動作として加熱
しないようにする。 Therefore, a heating device 35 is installed which detects this DC voltage at the low frequency s, compares this DC voltage Vamp with a reference voltage Vref by a comparator 33, and applies the comparison result to a temperature control circuit 34 as shown in FIG. 4B. By controlling the temperature, the temperature is controlled as shown in the drawing. In other words, the voltage Vamp is the reference voltage
In a state lower than Vref, the heating device 35 is activated to heat the electroacoustic transducer 17, and the reference voltage Vref is
If the temperature is higher than that, the heating device 35 is deactivated so that it does not heat up.
尚、第４図Ａ，Ｂにおいては、基準電圧Vref
として温度60℃における直流電圧を設定したが、
電気音響変換器１７の特性や密閉容器１１の形
式、或いは充填される液体１４の種類によつて所
望の値に設定する。この場合、基準電圧Vrefを
ある程度高く設定することにより制御温度域が高
くなり、液体１４がコーン振動板３６に付着した
場合でもこれを蒸発させることができ、電気音響
変換器１７の特性変化を防止できる。 In addition, in FIGS. 4A and 4B, the reference voltage Vref
The DC voltage at a temperature of 60℃ was set as
It is set to a desired value depending on the characteristics of the electroacoustic transducer 17, the type of the closed container 11, or the type of liquid 14 to be filled. In this case, by setting the reference voltage Vref high to a certain extent, the control temperature range becomes high, and even if the liquid 14 adheres to the cone diaphragm 36, it can be evaporated, thereby preventing changes in the characteristics of the electroacoustic transducer 17. can.
また、第３図Ｄに示す直流電圧Vlevelを得る
手段としては、VCO２１を300Hz程度の低周波で
一定時間（例えば２秒間）発振させて、その時の
信号振幅をAC／DC変換器３１により直流信号と
して読み出し、これを平均化回路３２に入力して
これを数回繰り返すことにより直流レベルの平均
値を算出する。または、予め抽出する低周波数を
設定し、掃引信号発生器１８からの鋸歯状波によ
るVCO２１の発振周波数がこの設定した低周波
数と一致したときにトリガ信号を加えてその時の
直流信号を読み出す。 In addition, as a means to obtain the DC voltage Vlevel shown in FIG. The average value of the DC level is calculated by inputting this into the averaging circuit 32 and repeating this several times. Alternatively, a low frequency to be extracted is set in advance, and when the oscillation frequency of the VCO 21 by the sawtooth wave from the sweep signal generator 18 matches the set low frequency, a trigger signal is applied and the DC signal at that time is read out.
（発明の効果）
以上のとおり、本発明によれば、電気音響変換
器の温度が基準値によつて決定される所定の温度
に保持されるようになり、温度変化によつて電気
音響変換器の定数が変化することがなくなるの
で、密閉容器内の空間部分の容積をより正確に測
定することができるようになる。(Effects of the Invention) As described above, according to the present invention, the temperature of the electroacoustic transducer is maintained at a predetermined temperature determined by a reference value, and the electroacoustic transducer is Since the constant of is no longer changed, the volume of the space inside the closed container can be measured more accurately.
また、本発明では、電気音響変換器自身が持つ
温度特性を利用してその温度を検出しているの
で、温度センサを別途設ける必要がなく温度検出
が容易に行えるようにしている。 Further, in the present invention, since the temperature is detected using the temperature characteristics of the electroacoustic transducer itself, there is no need to provide a separate temperature sensor, and temperature detection can be easily performed.
第１図は本発明に係る音響式容積測定装置の実
施例を示すブロツク図、第２図は従来の音響式容
積測定装置を示すブロツク図、第３図Ａ乃至Ｅは
それぞれ第１図及び第２図に係る装置における各
部波形図、第４図Ａ，Ｂはそれぞれ第２図に係る
装置における動作を説明するための特性図であ
る。
１１……密閉容器、１４……液体、１７……電
気音響変換器、２１……VCO、３１……AC／
DC変換器、３２……平均化回路、３３……コン
パレータ、３４……温度制御回路、３５……加熱
装置。
FIG. 1 is a block diagram showing an embodiment of the acoustic volume measuring device according to the present invention, FIG. 2 is a block diagram showing a conventional acoustic volume measuring device, and FIGS. 3A to 3E are respectively similar to FIGS. Waveform diagrams of various parts in the apparatus according to FIG. 2, and FIGS. 4A and 4B are characteristic diagrams for explaining the operation of the apparatus according to FIG. 2, respectively. 11...Airtight container, 14...Liquid, 17...Electroacoustic transducer, 21...VCO, 31...AC/
DC converter, 32... averaging circuit, 33... comparator, 34... temperature control circuit, 35... heating device.
Claims (1)
されることによつて前記密閉容器の容積を変化さ
せる電気音響変換器と、該電気音響変換器を連続
的に周波数が変化する電気信号で駆動する駆動手
段と、前記密閉容器の容積と前記電気音響変換器
の定数とによつて決まる共振周波数を検出する検
出手段とを備え、前記検出手段によつて検出した
共振周波数に基づいて前記密閉容器の容積を測定
する音響式容積測定装置であつて、 前記駆動手段が前記共振周波数より十分に低い
周波数の電気信号により前記電気音響変換器を駆
動しているとき、前記電気信号を直流に変換して
前記電気音響変換器の温度に応じた大きさの直流
信号を出力する直流変換手段と、 該直流変換手段が出力する直流信号と所定の温
度に対応する基準値とを比較するコンパレータ
と、 該コンパレータによる比較結果により動作する
温度制御手段と、 該温度制御手段によつて制御され、前記電気音
響変換器の可動部を加熱し、加熱部の温度を一定
に保つ加熱手段とを備え、 前記温度制御手段は、前記直流変換手段からの
直流信号に対応する温度が基準値によつて設定さ
れる温度より低いとき前記加熱手段による前記電
気音響変換器の加熱を行わせ、高いとき前記加熱
手段による前記電気音響変換器の加熱を停止させ
る、 ことを特徴とする音響式容積測定装置。[Scope of Claims] 1. An electroacoustic transducer that is provided to close an opening of a sealed container and changes the volume of the sealed container by being driven; a driving means that is driven by a changing electric signal; and a detection means that detects a resonance frequency determined by the volume of the sealed container and a constant of the electroacoustic transducer, the resonance frequency detected by the detection means; an acoustic volume measuring device that measures the volume of the sealed container based on the electric current, when the driving means drives the electroacoustic transducer with an electric signal having a frequency sufficiently lower than the resonance frequency; DC conversion means for converting a signal into DC and outputting a DC signal having a magnitude corresponding to the temperature of the electroacoustic transducer; and a DC signal output by the DC conversion means and a reference value corresponding to a predetermined temperature. a comparator for comparison; a temperature control means that operates according to the comparison result of the comparator; and a heating means that is controlled by the temperature control means and heats the movable part of the electroacoustic transducer to keep the temperature of the heating part constant. The temperature control means causes the heating means to heat the electroacoustic transducer when the temperature corresponding to the DC signal from the DC conversion means is lower than the temperature set by a reference value; An acoustic volume measuring device characterized in that when the temperature is high, heating of the electroacoustic transducer by the heating means is stopped.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1343185A JPS61173119A (en) | 1985-01-29 | 1985-01-29 | Acoustic type volume measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1343185A JPS61173119A (en) | 1985-01-29 | 1985-01-29 | Acoustic type volume measuring instrument |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61173119A JPS61173119A (en) | 1986-08-04 |
| JPH0362205B2 true JPH0362205B2 (en) | 1991-09-25 |
Family
ID=11832944
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1343185A Granted JPS61173119A (en) | 1985-01-29 | 1985-01-29 | Acoustic type volume measuring instrument |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61173119A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10859421B2 (en) | 2017-05-23 | 2020-12-08 | Michigan Scientific Corporation | Electro acoustic volume measurement |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53136865A (en) * | 1977-04-28 | 1978-11-29 | Nippon Soken | Measuring apparatus for volume |
| JPS56117122A (en) * | 1980-02-22 | 1981-09-14 | Oval Eng Co Ltd | Automatic testing device for flow rate or the like using sound speed nozzle |
-
1985
- 1985-01-29 JP JP1343185A patent/JPS61173119A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53136865A (en) * | 1977-04-28 | 1978-11-29 | Nippon Soken | Measuring apparatus for volume |
| JPS56117122A (en) * | 1980-02-22 | 1981-09-14 | Oval Eng Co Ltd | Automatic testing device for flow rate or the like using sound speed nozzle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61173119A (en) | 1986-08-04 |
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