JPH0545192A - Vortex flowmeter converter - Google Patents

Abstract

PURPOSE:To identify automatically whether a fluid flowing through the same flow tube is either liquid or gas, without being affected by the noise component of the flow, and carry out the flow measurement of the fluid with one vortex flowmeter. CONSTITUTION:An input signal of a sensor 1 is amplified with a charge amplifier 2, and inputted to a conversion circuit 3 for gas and a conversion circuit 4 for liquid. In the measurement time of a liquid flow, the signal input of the gas is forbidden and only a liquid flow pulse is outputted from a terminal 11, through an inverter 6, and the first and the third AND gates 5, 9 with a low level signal outputted from a high frequency detecting circuit 33 for gas and a high level signal outputted from a pulse detecting circuit 43 for liquid. In the measurement time of a gas flow, the liquid flow pulse is not outputted, and the gas flow pulse is outputted through an inverter 8, and the second AND gate 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid and gas conversion circuit for a vortex flowmeter arranged in a flow tube for changing the flow rate of either liquid or gas flowing through the same flow tube. The present invention relates to a converter of a vortex flowmeter having a function of automatically switching any one of them and selectively outputting a flow rate pulse of a corresponding fluid.

[0002]

2. Description of the Related Art As is well known, an vortex flowmeter is installed in a flow tube, detects Karman vortices generated and separated from the vortex generator, and obtains the flow rate from the number of vortices per unit time. With the principle and structure, the vortex signal can be easily converted into a pulse signal and a digital flow rate signal can be obtained.
Since the measurable flow rate range is wide, it is useful as a flow rate detection end in instrumentation, and in recent years, the types of measurement fluids and the applicable range have been expanded. Also, the pulse constant of the flow pulse of the vortex flowmeter is determined by the Strouhal number, but since this Strouhal number depends on the Reynolds number, the pulse constant is determined within the range where the Strouhal number is constant, gas, liquid Even in fluids with different densities, there is also an advantage that the flow pulse can be calculated and measured without changing the pulse constant within the Reynolds number range, and the flow rate of liquid or gas can be measured with one vortex flowmeter. Is being attempted. For example, after repeating measurement of the liquid A, steam cleaning, switching to the liquid B, steam cleaning again, and measurement of the liquid A are repeated. In this case, the flow rates of the A liquid, the B liquid and the vapor are naturally measured for each liquid.

On the other hand, as a method of detecting vortices in a vortex flowmeter, a method of utilizing vortex fluctuation pressure or lift change is often used, and these detection signals are the fluid density and the flow velocity.
The signal level is proportional to the power. In industrial applications, a liquid to be measured has a high density and a low flow rate, but a gas has a low density and a high flow rate, so that the frequency range of the vortex signal in the measurement flow range of the liquid and the gas is And the signal level is significantly different, and when measuring the flow rate of liquid and gas with one vortex flowmeter, conventionally, a signal converter for liquid (hereinafter simply referred to as a converter) and a converter for gas are placed side by side. However, the switching of each converter is manually switched at the time of switching the flow path from the fluid source of liquid or gas. In this method, there is the complexity of switching the fluid converter at the time of switching the fluid path flowing from the fluid source of liquid or gas into the flow tube, and there is also the risk of erroneous operation.

To solve the above problems, Japanese Patent Application No. 1-2933
In the vortex flowmeter converter of No. 5, whether the fluid flowing through the same flow pipe is a liquid or a gas is automatically determined and measured. This vortex flowmeter converter utilizes the fact that the frequency of the vortex signal is low for liquid and high for gas, and the vortex signal of liquid and the vortex signal of liquid are provided by each band filter that covers the measurement range of liquid and gas, respectively. The vortex signal of gas is separated and output. The principle of this signal separation is that the vortex frequency of the detectable gas signal level is included in the frequency range having the vortex signal level of the liquid, and the detectable vortex frequency is included in the frequency range of the vortex signal level of the gas. Paying attention to the fact that the vortex signal level of 1 is not included, the vortex signal of the vortex frequency of the gas is passed as it is and output. On the other hand, the vortex signal of the vortex frequency of the liquid is a signal which is pulse-converted from the vortex signal of the liquid and is output by blocking the vortex signal of the gas by the inhibition signal.

The above-mentioned conventional technique is satisfied under the condition that the gas vortex signal does not include the signal of the component in the frequency band of the liquid vortex signal. However, when the gas flow rate increases, the normal vortex signal is generated. There is a problem in that the signal is modulated by low frequency noise and is measured as a malfunction liquid vortex signal due to this noise component.

[0006]

[PROBLEMS] The present invention has been made in view of the above-mentioned problems, and when either liquid or gas is circulated in the same flow tube and the liquid or gas is measured by a vortex flowmeter, any fluid currently circulated. It is an object of the present invention to provide a vortex flowmeter converter for measuring the flow rate of the fluid by switching the above, without being affected by the flow noise component.

[0007]

In order to achieve the above object, the present invention provides (1)
In a converter of a vortex flowmeter that measures the flow rate of either liquid or gas passing through the same flow tube, an amplifier circuit that amplifies a vortex signal, and a liquid conversion circuit and gas connected to the amplifier circuit. A conversion circuit and a gate circuit connected to the liquid conversion circuit and the gas conversion circuit. The liquid conversion circuit converts a vortex signal having a low upper limit frequency in a liquid flow rate range into a liquid flow rate pulse, and converts the vortex signal to a high value during conversion. A level signal is output, the gas conversion circuit converts a high upper frequency vortex signal in a gas flow rate range into a gas flow rate pulse, and outputs a high level signal when the converted gas flow rate pulse has a high frequency, and the gate circuit Prohibits the high-level output of the liquid conversion circuit by the high-level signal of the gas conversion circuit, and the low-frequency component node detected by the liquid conversion circuit at the time of measuring the gas flow rate. The liquid flow pulse is closed by the high level signal of the liquid conversion circuit to output only the liquid flow pulse signal during liquid flow measurement, and the liquid flow pulse is closed during gas flow measurement. Outputting only a gas flow rate pulse signal; and (2) in (1), in the gas conversion circuit, when the frequency of the output pulse output by the gas conversion circuit is lower than the set frequency, And the output frequency is higher than the set frequency and discontinuous, and the output pulse is output when the frequency of the output pulse is higher than the set frequency and continuous. ,
It has a frequency dividing counter for setting the number of output pulses in order to determine the number of discontinuous output pulses. An embodiment of the vortex flowmeter converter of the present invention will be described below.

FIG. 1 is a block diagram showing the construction of an embodiment of the vortex flowmeter converter of the present invention. In the figure, 1 is a sensor, 2 is a charge amplifier, 3 is a gas conversion circuit, and 31 is a gas. Amplifier, 32 is a trigger circuit, 33 is a high frequency detection circuit, 4 is a liquid conversion circuit, 41 is a liquid amplifier, 42 is a trigger circuit, 43 is a pulse detection circuit, 5 is a first AND gate, 6 is an inverter, 7 Is the second AND gate, 8
Is an inverter, 9 is a third AND gate, 10 is an OR gate, and 11 is an output terminal.

In the figure, a sensor 1 is a sensor which is interposed in a flow tube (not shown) and detects a vortex signal of a vortex flow meter for measuring a liquid or gas flow rate. The piezoelectric element sensor which detects is shown. The detection signal is output at a level proportional to the piezoelectric coefficient, the fluid density, and the square of the flow rate. The charge amplifier 2 receives the high-impedance piezoelectric signal and proportionally amplifies a wide range of vortex frequencies corresponding to the flow range of liquid and gas. The charge amplifier 2 is connected to the gas conversion circuit 3 and the liquid conversion circuit 4. The gas conversion circuit 3 is a circuit that outputs a vortex signal having a high upper limit frequency of a gas flow range as a gas flow pulse, and includes an amplifier 31 and a trigger circuit 32.
And a high frequency detection circuit 33 that outputs a high level signal when the gas flow rate pulse has a high frequency. The liquid conversion circuit 4 is a circuit that outputs a vortex signal having a low upper limit frequency of the liquid flow rate range as a liquid pulse, and includes an amplifier 41, a trigger circuit 42, and pulse detection that outputs a high level signal during liquid measurement. And a circuit 43. The first AND gate 5 inputs the signal from the inverter 6 and the output of the pulse detection circuit 43 to the output of the high frequency detection circuit 33. The second AND gate 7 inputs the gas flow rate pulse output of the gas conversion circuit 3 and the output of the first gate via the inverter 8. The third AND gate 9 is used for the liquid conversion circuit 4
The liquid flow rate pulse output and the output of the first gate 5 are input. The OR gate 10 receives the second and third AND gate outputs 7 and 9 and outputs a liquid or gas flow rate pulse from the output terminal 11.

Next, the operation of the illustrated block diagram will be described. The output of the charge amplifier 2 is input to the gas amplifier 31 and the liquid amplifier 41 at the same time. The gas amplifier 31 amplifies a high vortex frequency corresponding to a gas flow rate having a high flow rate, and a frequency outside the flow rate range. A high-order low-pass filter is provided in order to block the components and reduce the signal level change. Similarly for the liquid amplifier 41,
It has a suitable high-order low-pass filter corresponding to a low vortex frequency corresponding to a liquid flow rate having a small flow velocity.

FIG. 5 is a diagram showing the amplifier characteristics of the liquid amplifier 41 and the gas amplifier 31 during liquid measurement. In the figure, A (solid line) is the liquid amplifier characteristic, and B (dotted line).
Is a gas amplifier characteristic. A _L and B _L in the figure represent the liquid amplifier output and the gas amplifier output, and the level corresponding to the vertical axis OdB is the trigger circuit 42 of the next stage.
This is the lower limit level required to output the flow rate pulse. Area of the shaded C may represent a liquid flow rate range Q _L, the liquid flow rate range Q _L, liquid amplifier output A _L (solid line), of course, the flow rate pulse a vortex signal in the next stage of the trigger circuit 42 Is amplified to a level sufficient to output, and has a sufficient level even at the lower limit flow rate. However, at the same time, the gas amplifier output B _L (dotted line) also has the lower limit of the frequency of P _G ,
It is amplified to a level sufficient to output a flow pulse.

FIG. 6 is a diagram showing the amplifier characteristics of the liquid amplifier 41 and the gas amplifier 31 at the time of gas measurement, and A and B are the respective amplifier characteristics common to FIG. The hatched area D indicates the gas flow rate range Q _G , but in this range, the output B _G of the gas amplifier 31 (dotted line)
Is amplified to a level sufficient to output a flow rate pulse in the trigger circuit of the next stage, but the liquid amplifier 41 output A
_G (solid line) does not have the level required to output the flow pulse. That is, when measuring the liquid, the liquid trigger circuit 42,
Flow rate pulses are output from both the gas trigger circuits 32, but during gas measurement, flow rate pulses are obtained only from the gas trigger circuit 32, and flow rate pulses are not output from the liquid trigger circuit 42. Therefore, when the flow rate pulse is output to the liquid trigger circuit 42, it can be determined that the liquid measurement is in progress, and when the flow rate pulse is not output to the liquid trigger circuit 42, it is determined that the gas measurement is in progress. it can.

The pulse detection circuit 43 is a circuit for detecting the output of the flow rate pulse from the liquid trigger circuit 42, and outputs a high level signal when the frequency of the flow rate pulse is higher than the lower limit frequency of the liquid flow rate range. Output. Also,
The high frequency detection circuit 33 is for the purpose of preventing the pulse detection circuit 43 from malfunctioning due to noise input to the liquid conversion circuit 4 when measuring the gas flow rate, and detects the flow rate pulse output from the gas trigger circuit 32. When the frequency is higher than the upper limit frequency of the liquid flow rate range, a high level signal is output and the output of the pulse detection circuit 43 is prohibited.

FIG. 2 is a block diagram showing the principle of the pulse detection circuit 43 and the high frequency detection circuit 33. In FIG.
Is an input terminal, 13 is a first monostable multivibrator (hereinafter simply referred to as monomulti), 14 is a second monomulti, 1
Reference numeral 5 is an AND gate, and 16 is an inverter.

In the figure, the signal A at the input terminal 12 connected to the output of the trigger circuit 32 is input to the first monomulti 13 and the inverter 16, and the outputs C and B are input to the AND gate 15. Output D of the AND gate 15
Input to the second monomulti 14, and output E is output from the terminal 17. The high-level pulse width (time) of the pulse C output from the mono-multi 13 is set to be 1/2 of the pulse interval time at the frequency detected by the high-frequency detection circuit 33 and the pulse detection circuit 43. High-level pulse width (time) of pulse E output by 14
Is set to be larger than the pulse interval time at the frequency detected by the high frequency detection circuit 33 and the pulse detection circuit 43.

FIG. 7 is a diagram showing a time chart for explaining the operations of the pulse detection circuit 43 and the high frequency detection circuit 33, and shows the case where the frequency of the input pulse is smaller than the detected frequency. In the figure, since the high level time T1 of the pulse C output from the first monomulti 13 is smaller than T2, which is 1/2 of the pulse interval time of the input pulse A, triggered by the rising edge of the input pulse A,
The output D of the AND gate 15 remains at a low level,
The output E of the second monomulti 14 also remains at a low level.

FIG. 8 is a time chart for explaining the operation of the pulse detection circuit 43 and the high frequency detection circuit 33, and shows the case where the frequency of the input pulse is higher than the frequency to be detected. In the figure, the pulse width T ₂ of the input pulse A is ½ of the pulse interval time.
Is smaller than the high-level time T1 of the pulse C output from the first mono-multi 13, triggered by the rising edge of the input pulse A, so the pulse D is output to the output of the AND gate 15 and the second mono-multi is output. 14 outputs the output E. Since the high level time T3 of the pulse output from the second monomulti 14 is set to be larger than the pulse interval time at the frequency to be detected, before the high level time T3 ends, the next AND gate 15 outputs The output D is input, and as a result, the second monomulti 1
The output of 4 remains at a high level, serving the purpose of high frequency detection and pulse detection.

Further, the first AND gate 5, the inverter 6, the second AND gate 7, the inverter 8, the third AND gate 9 and the OR gate 10 utilize the above-mentioned vortex signal characteristics to measure the liquid flow rate. Is a gate circuit that outputs a liquid flow pulse and a gas flow pulse signal when measuring the gas flow. When measuring the liquid flow rate, a high level signal which is the output of the pulse detection circuit 43 in the liquid conversion circuit 4,
The low level signal output from the high frequency detection circuit 33 in the gas conversion circuit 3 and the high level signal inverted by the inverter 6 are input, and the output of the first AND gate 5 becomes a high level signal. Since this high level signal is input to the second AND gate 7 via the inverter 8, the second AND gate 7 is closed and the gas flow rate pulse is not output. On the other hand, the third AND gate 9 is opened, and only the liquid flow rate pulse is output via the OR circuit 10. When measuring the gas flow rate, the output of the pulse detection circuit 43 in the liquid conversion circuit 4 becomes a low level signal and the third gate 9 is closed. As a result, the liquid flow rate pulse is not output and the gas flow rate pulse is not output. Only output.
Further, during gas measurement such that the frequency of the flow rate pulse exceeds the upper limit frequency of the liquid flow rate range, the output of the high frequency detection circuit 33 in the gas conversion circuit 3 becomes a high level, and the pulse in the liquid conversion circuit 4 becomes high. Detection circuit 4
Since the first AND gate 5 connected to the output of 3 is closed, noise appears in the liquid conversion circuit 4 and the pulse detection circuit 4
Even if 3 detects a pulse, the liquid flow rate pulse is not output, and a malfunction can be prevented.

In the above vortex flowmeter conversion circuit, the output pulse transmitted from each conversion circuit is a pulse signal having a pulse width according to the pulse width of the liquid measurement range when the liquid is measured, Even in the case of gas measurement, when a similar pulse signal is input normally and when noise is generated in the liquid conversion circuit 4, normal operation is performed according to the circuit block of FIG. When the noise generated at 31 is generated as a noise pulse due to the high frequency noise from the gas conversion circuit 3, there is a problem that the first gate 5 is closed and the output of the liquid pulse signal is prohibited.

FIG. 3 is a block diagram showing the configuration of another embodiment of the vortex flowmeter converter of the present invention. In the figure, 3a is a gas conversion circuit and 33a is a continuous high frequency detection circuit, the same as in FIG. The parts that operate are given the same reference numerals.

The continuous high-frequency detection circuit 33a is a circuit for preventing malfunction caused by high-frequency noise appearing in the output of the gas amplifier 31 during liquid measurement. That is, the output of the signal pulse of the liquid conversion circuit 4 is prohibited only when the input pulse of the gas vortex signal is continuously generated, and the liquid signal pulse is output when the noise pulse of the high frequency noise is output. Circuit.

FIG. 4 is a block diagram showing the principle of the continuous high frequency detecting circuit 33a. In the figure, 18 is an input terminal, 19 is a monomulti, 20 is an inverter, 21 is a frequency dividing counter,
22 is an AND gate, and 23 and 24 are inverters.

In the figure, the signal F at the input terminal 18 connected to the output of the trigger circuit 32 is a monomulti 19 respectively.
To the AND gate 22 and the output G of the monomulti 19
Is input to the reset terminal of the frequency dividing counter 21 via the inverter 20. The output of the frequency division counter 21 is output to the terminal 25.
Simultaneously with the output, it is input to the AND gate 22 via the inverter 23, and the output K of the AND gate 22 is input to the frequency division counter 21 via the inverter 24. The high-level pulse width (time) of the pulse G output from the monomulti 19 is set to be the pulse interval time at the frequency detected by the continuous high frequency detection circuit 33a,
The frequency division value of the frequency division counter is the continuous high frequency detection circuit 33a.
It is set so that the pulse of the frequency to be detected in step 2 will be the lower limit pulse number (2 pulses or more) which is a reference for judging that it is continuous.

9 to 11 show a continuous high frequency detecting circuit 33.
FIG. 6 is a diagram showing a time chart for explaining the operation of a.
In the case where the frequency of the input pulse is smaller than the detected frequency, the output I of the frequency dividing counter 21 is at a low level in the initial state of FIG.
Becomes a high level, the AND gate 22 is opened, and the input pulse F becomes a pulse L passing through the AND gate 22 and the inverter 24, and is input to the frequency dividing counter 21. On the other hand, the high level time T3 of the pulse G output from the monomulti 19 triggered by the rising edge of the input pulse F is
Since it is smaller than the pulse interval time T4 of the input pulse F,
The frequency dividing counter 21 is reset for each pulse of the input pulse F by the signal H via the inverter to the output signal G of the mono-multi. As a result, since the frequency division counter 21 cannot count more than one pulse, the output I of the frequency division counter 21 remains at a low level and the output 25 of the continuous high frequency detection circuit 33a also remains at a low level. Figure 10
Shows the case where the frequency of the input pulse is higher than the detected frequency and is not continuous, and FIG. 11 shows the case where the frequency of the input pulse is higher than the detected frequency and continuous.

In the case where the frequency of the input pulse is higher than the detected frequency and is not continuous in FIG. 10, the initial state is the same as that in FIG. 8, but the pulse interval time T4 of the input pulse F is the same as that of the input pulse F. Since the pulse G output by the mono-multi 19 with the rising edge as a trigger is smaller than the high-level time T3, the trigger is applied again by the pulse F before the mono-multi 19 ends its operation. The operation of outputting a pulse whose high level time is T3 is started. The output G of the mono-multi 19 maintains a high level from the rising edge of the first pulse of the input pulse F to a time T3 after the rising edge of the last pulse, during which the reset of the frequency dividing counter 21 is released. The frequency division counter 21 counts the input pulses L that have passed through the AND gate 22 and the inverter 24 while the reset is released, and the number of input pulses (3 pulses in the case shown) is set in the frequency division counter 21. Since it is smaller than the frequency division value (4 pulses in the illustrated case), the output I of the frequency division counter 21 remains at a low level, and the output 25 of the continuous high frequency detection circuit 33a also remains at a low level. Moreover, after T3 time from the rising of the last pulse of the input pulse F, the output G of the monomulti 19 becomes a low level, so the frequency division counter 21 is reset and returns to the initial state, and the continuous high frequency detection circuit 33a operates. The output 25 never goes high.

When the frequency of the input pulse in FIG. 11 is higher than the detected frequency and is continuous, the operation up to the third pulse of the input pulse F is the same as in FIG.
Since the input pulse F is continuously input even after the fourth pulse, the output G of the monomulti 19 remains at the high level from the rising edge of the first pulse of the input pulse F, and the reset of the frequency division counter 21 is also released. Will remain. When the number of pulses of the pulse L input to the frequency division counter 21 through the AND gate 22 and the inverter 24 reaches the frequency division value set in the frequency division counter 21 (4 pulses in the case shown in the figure), The output I of the frequency counter 21 becomes high level, the output J of the inverter 23 becomes low level by the output, and the AND gate 22 is closed. Since the input pulse F is not transmitted to the output K of the AND gate 22, the counting of the frequency dividing counter 21 is stopped, the output I of the frequency dividing counter 21 is fixed at a high level, and the output 25 of the continuous high frequency detecting circuit 33a is also changed. It remains at a high level and serves the purpose of a continuous high frequency detection circuit.

[0027]

As described above, the vortex flowmeter converter of the present invention has the following effects. (1) Effect corresponding to claim 1: Even when liquid or gas flows through the same flow tube, the flow pulse signal of liquid or gas is automatically discriminated and switched and output, so there is no human error. Also, simple instrumentation can be performed without the complexity of switching the gas and liquid converters at the same time as switching the flow paths. (2) Effect corresponding to claim 2: A pulse signal output from the high-frequency detection circuit of the gas converter is a circuit in which input pulses are continuously input, and the continuity is determined in advance as a method for determining the continuity. It is possible to set the lower limit number of pulses as a reference, and if the number of pulses that come continuously even at high frequencies is less than the set number of pulses,
Prevented the detection circuit from detecting. As a result, it is possible to prevent an erroneous operation in which the gas amplifier inhibits liquid discrimination due to harmonic noise when measuring liquid.

[Brief description of drawings]

FIG. 1 is a block diagram of circuit elements constituting an embodiment of a vortex flowmeter converter of the present invention.

FIG. 2 is a circuit block diagram of a high frequency detection circuit and a pulse detection circuit used in the configuration circuit of FIG.

FIG. 3 is a block diagram of circuit elements constituting another embodiment of the vortex flowmeter converter of the present invention.

4 is a circuit block diagram of a continuous high frequency detection circuit adopted in the configuration circuit of FIG.

FIG. 5 is an amplifier characteristic when measuring a liquid.

FIG. 6 is an amplifier characteristic at the time of gas measurement.

FIG. 7 is a diagram showing an operation time chart of the high frequency detection circuit and the pulse detection circuit when the pulse frequency is low in the circuit block diagram of FIG. 2;

8 is a diagram showing an operation time chart of the high frequency detection circuit and the pulse detection circuit when the frequency is high in the circuit block diagram of FIG.

9 is a diagram showing an operation time chart of the continuous high frequency detection circuit when the pulse frequency is small in the circuit block diagram of FIG.

10 is a diagram showing an operation time chart of the continuous high frequency detection circuit when the pulse frequency is high and the pulses are not continuous in the circuit block diagram of FIG.

FIG. 11 is a diagram showing an operation time chart of the continuous high frequency detection circuit when the pulse frequency is high and the pulses are continuous in the circuit block diagram of FIG. 4.

[Explanation of symbols]

1 ... Sensor, 2 ... Charge amplifier, 3 ... Gas conversion circuit, 4 ... Liquid conversion circuit, 5 ... First AND gate,
6, 8, 23, 24 ... Inverter, 7 ... Second AND gate, 9 ... Third AND gate, 10 ... OR gate, 1
1, 17, 25 ... Output terminal, 12, 18 ... Input terminal, 1
3, 14, 19 ... Monostable multivibrator, 15, 2
2 ... AND gate, 16, 23, 24 ... Inverter, 2
1 ... Division counter.

Claims (2)

[Claims] 1. A vortex flowmeter converter for measuring the flow rate of either a liquid or a gas passing through the same flow tube, an amplifier circuit for amplifying a vortex signal, and a liquid connected to the amplifier circuit. And a gas conversion circuit, and a gate circuit connected to the liquid conversion circuit and the gas conversion circuit, the liquid conversion circuit converting a vortex signal having a low upper limit frequency in a liquid flow rate range into a liquid flow rate pulse. Then
A high level signal is output during conversion, the gas conversion circuit converts a high upper frequency vortex signal in the gas flow rate range into a gas flow rate pulse, and outputs a high level signal when the converted gas flow rate pulse has a high frequency, The gate circuit inhibits the high level output of the liquid conversion circuit by the high level signal of the gas conversion circuit, prevents malfunction due to low frequency component noise detected by the liquid conversion circuit when measuring the gas flow rate, and At the time of measurement, the gas flow rate pulse is closed by the high level signal of the liquid conversion circuit and only the liquid flow rate pulse signal is output, and at the time of gas flow rate measurement, the liquid flow rate pulse is closed and only the gas flow rate pulse signal is output. Vortex flowmeter converter characterized by. 2. In the gas conversion circuit, when the frequency of the output pulse output by the gas conversion circuit is lower than the set frequency, and higher than the set frequency,
And, when it is discontinuous, the output of the output pulse is prohibited, and the frequency of the output pulse is higher than the set frequency,
2. The vortex flow rate according to claim 1, further comprising a frequency dividing counter that outputs the output pulse when it is continuous and sets the number of output pulses to determine the number of the discontinuous output pulses. Meter converter.