JPH0174527U - - Google Patents

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本考案の１実施例の構成を示すブロツ
ク図、第２図は本考案の第２の実施例の構成を示
すブロツク図、第３図は第２図に示す各部の波形
を示す波形図、第４図は従来の電磁流量計の構成
を示すブロツク図、第５図は第４図に示す各部の
波形を示す波形図である。 １０……導管、１２……励磁コイル、１３……
励磁回路、１６，１７……低域濾波器、１８……
タイミング回路、１９……ローパスフイルタ、２
０……ハイパスフイルタ、２１……加算点、２３
，２６，２７……雑音検出回路。 Figure 1 is a block diagram showing the configuration of one embodiment of the present invention, Figure 2 is a block diagram showing the configuration of a second embodiment of the present invention, and Figure 3 shows waveforms of each part shown in Figure 2. FIG. 4 is a block diagram showing the configuration of a conventional electromagnetic flowmeter, and FIG. 5 is a waveform chart showing waveforms of each part shown in FIG. 4. 10... Conduit, 12... Excitation coil, 13...
Excitation circuit, 16, 17...Low pass filter, 18...
Timing circuit, 19...Low pass filter, 2
0...High pass filter, 21...Additional point, 23
, 26, 27... Noise detection circuit.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 第１周波数とこれより低い第２周波数の２つの
異なつた周波数を有する磁場を供給する励磁手段
と、この励磁手段により励磁され流量に対応して
発生する信号電圧を前記第１周波数に基づいて弁
別して出力する第１復調手段と、この第１復調手
段の出力を高域濾波するハイパスフイルタと、前
記信号電圧を前記第２周波数に基づいて弁別して
復調する第２復調手段と、この第２復調手段の出
力を低域濾波するローパスフイルタと、前記ハイ
パスフイルタと前記ローパスフイルタとの各出力
を加算的に合成する加算手段と、前記第２復調手
段の出力揺動の上限値を決める第１基準電圧とこ
の出力揺動の下限値を決める第２基準電圧とが与
えられこの上限値或いは下限値と前記第２復調手
段の出力とを用いて前記上限値或いは下限値を越
える前記出力揺動があつたときは異常出力を出す
ヒステリシスが付与された比較手段と、この異常
出力のないとき或いは前記異常出力から所定期間
の間に再び前記異常出力が入力されないときは正
常出力を出すリトリガラブルモノマルチ手段と、
前記異常出力により前記加算手段の出力に或いは
前記正常出力により前記第２復調手段の出力にそ
れぞれ切り替えて流量出力を出す切替手段とを具
備することを特徴とする電磁流量計。 an excitation means for supplying magnetic fields having two different frequencies, a first frequency and a second frequency lower than the first frequency; and a signal voltage excited by the excitation means to be generated corresponding to the flow rate. a first demodulating means for separately outputting the output; a high-pass filter for high-pass filtering the output of the first demodulating means; a second demodulating means for discriminating and demodulating the signal voltage based on the second frequency; a low-pass filter for low-pass filtering the output of the means; an adding means for additively combining the respective outputs of the high-pass filter and the low-pass filter; and a first criterion for determining an upper limit value of the output fluctuation of the second demodulating means. A voltage and a second reference voltage that determines the lower limit value of this output fluctuation are given, and the output fluctuation exceeding the upper limit value or lower limit value is determined using this upper limit value or lower limit value and the output of the second demodulation means. A comparison means provided with hysteresis that outputs an abnormal output when the temperature is high, and a retriggerable device that outputs a normal output when there is no abnormal output or when the abnormal output is not input again within a predetermined period after the abnormal output. Multi-method and
An electromagnetic flowmeter characterized by comprising a switching means for outputting a flow rate output by switching to the output of the adding means in response to the abnormal output or to the output of the second demodulating means in response to the normal output.