JPS604817A - Flow rate measuring apparatus - Google Patents

Abstract

PURPOSE:To measure the flow rate accurately by counting pulses from a flow rate sensor while the time is measured from the first to last flow rate pulse within a unit measuring time length to make the flow rate pulse synchronizing the measured time. CONSTITUTION:A flow rate sensor 2 is provided in a gas supply line 1 and a sensor 2 made up of a membrane type gas meter 3 and a lead switch 4 as a magnetic field sensor to transmit a flow rate pulse F each time measuring a specified unit weighing volume. The pulse F is inputted into an arithmetic processor 5 which computes the flow rate per unit time. A counter 6 of the device 5 counts the number of the pulses F and a timer 7 measures the time from the first to last flow rare pulse within a unit measuring time. An arithmetic processing section 8 computes and outputs the flow rate Q per unit time from the pulses counted with the counter 6 and the time length measured with the time 7. Thus, the flow rate per unit time can be measured accurately by having the flow rate pulses synchronizing the measured time length.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fluid flow rate measurement device, and more particularly to a flow rate measurement device suitable for a device that requires measurement of flow rate per unit time.

Conventional configuration and its problems Conventional flow rate measuring devices consist of a gas meter installed in the fluid supply line, and a permanent magnet permanently fixed to the rotating shaft inside the gas meter. A control device is provided with a hole I (ii) for detecting the magnetic field of the magnet, transmits one flow pulse every time the disk rotates, counts the number of flow pulses per minute with a counter, and calculates the total average flow rate. This device calculates the average flow rate from the number of flow pulses within a predetermined time, but it has the following problems.If the flow pulses and the predetermined time can be synchronized, the average flow rate can be calculated accurately. It can be calculated, but if synchronization is not achieved, that is, if the conditions that a flow rate pulse is input at the start of a predetermined time and a flow rate pulse is also input at the elapse of a predetermined time do not hold, an incorrect H average flow rate will be calculated. In other words, the average flow rate that is positive i only when the time interval of the flow rate pulse is an integer fraction of the predetermined time p and the flow rate pulse is input at the measurement start point is;
can be calculated, otherwise it will be inaccurate.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks.
By synchronizing the pulse and measurement time, positive 6f+
i;'I: The purpose is to measure the flow rate per hour.

Structure of the Invention In order to achieve the above object, the flow rate measuring device of the present invention provides a flow measuring device in which a flow rate pulse is emitted every time a predetermined unit measurement volume of fluid flow is measured in a fluid supply line. In response to this flow rate pulse, a counter counts the number of flow rate pulses, and a timer measures this counted value and the time from the start of measurement to the time when the last flowmeter pulse is input within a predetermined unit measurement time. The arithmetic processing unit calculates the flow rate per unit time from this measurement time, and measurement starts when the first flow pulse is input manually, and when the last flow pulse is input within a predetermined time. The time spent on a call is measured, and the total flow rate per unit time is calculated from this time and the number of flowmeter pulses, so the flow rate pulse and measurement time are completely synchronized, resulting in extremely accurate measurements. .

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a gas supply line, 2 is a flow rate sensor installed in the gas supply line, and a model gas meter 3,
A reed switch 4 serves as a magnetic field sensor that detects the magnetic field of a magnet installed in a metering response part of a model gas meter, such as a membrane, a link mechanism that transmits displacement of the membrane, etc., and the meter 3 is the unit of the reed switch. When the measured volume is measured, a flow rate pulse that turns from off to on is transmitted. Reference numeral 5 denotes an arithmetic processing unit to which the flow rate pulse FQ is input, and is configured as follows. 6Fi is a counter that counts flow rate pulses Fi and outputs the count as FC; 7 is a timer that outputs as measurement time iT. 8 is an arithmetic processing unit which outputs the flow rate pulse F, the counter output FC timer output T, the previously measured flow rate pulse time interval (hereinafter abbreviated as the previous interval) T' as the output of the storage unit 9, and the timer measurement time 10. T.A.
as input, counter 6ff: reset signal OR,
Timer γ Full reset signal TR1 Stored data signal TD in storage section 9, Timer 1o'off: Control signal TA',
1'-()'L flow rate calculation result per hour Q1 change signal q
Let be the output. The timer 10 measures the time after the start of the measurement, and in the example shown in the figure, it is set to zero by the arithmetic processing unit 8 at the time of the start of the measurement, which is a memory, and each time the flow rate pulse interval is measured by the timer 7, the measurement is The time is multiplied by the past measurement time stored in the storage device 1Q in the arithmetic processing unit 8, and the result is stored in the storage device 10. Therefore, memory 10
The contents of the timer function as a type of timer that saves the entire measurement time at which the flow pulse is input.

The operation of the above configuration will be described below with reference to the timing chart for explaining the operation in FIG.

In Figure 2, (a) is the unit 1 in which the entire gas supply line is flowing.
1.5 hours, (b) is the flow rate pulse F, H is the predetermined time for measurement, (b) is the flow rate measurement time, and (e) is the flow rate 1-indicated by the arithmetic processing unit. . Suppose that the i-th measurement is started at time to while a constant flow rate Q1 is flowing.The guru interval at this time is T1, and at time t1 after to, 1:9 hours T1. The first flow rate pulse F is transmitted. The counter 6 counts this as 1, and the arithmetic processing unit 8 inputs the entire output T of the timer 7 and compares it with the previous interval T' in the storage unit 9 as follows. i
First, the current measurement interval T1 is multiplied by a predetermined number α. This α is the permissible fluctuation l] taking into consideration variations in the time interval of flow rate and gas that occur when a constant flow rate is flowing, and is, for example, 1 %. Next, calculate the absolute value IT'-T11' of the difference between the previous interval T' and the current interval. Compare the previously calculated α・T1 and IT'-T11, and if α・T1≧IT
'-T11, continue the entire measurement, α・T1〈IT'-T
+l, all measurements for this time will be stopped.O Since the flow rate is now constant, the measurement will be continued from time t1 onwards at the previous interval T'+T1. In order to continue the measurement at time t1, the arithmetic processing unit 8 resets the timer 7 with the full signal TR and adds the measurement time TA (currently zero) in the memory 10 and T1, that is, T1-1-TA=T1+○ = T1° The result is all newly outputted to the memory 10 as Tp, and the stored data in the memory 1o becomes T1. Thereafter, the same operation is repeated, and at time t5, time t is reached. Since the predetermined unit measurement time TM has elapsed, the arithmetic processing unit 8 changes the count value FC of the counter 6 to N.
, the time TA until the last N-th flow rate pulse is input before the predetermined unit measurement time TM that has been measured so far and is stored in the memory 10, and the predetermined unit sugar volume Fu. Therefore, the flow rate Q1 per unit time is Q,=Fu
・Calculate l: on N/TA, output the result as total Q1, and reset the counter 6 total signal CR.
1. Reset all stored data in the storage device 10 as TP20 and prepare for the next opening.

Next, the case where the flow rate is extremely low and no flow pulse is input within the unit measurement time TM will be explained using FIG. 3. The first flow pulse F is at time t. is input.

Since the flow rate is small, the unit measurement time TM, J:! ll long pulse interval T 2 > T 1 .

Zunawaji time t. At time t, after 1M has elapsed, the count value FC of the counter 6 remains at zero.

The arithmetic processing unit 8 operates the timer γ for the first time.

At time t2, the first flow rate pulse F is input.

Therefore, the arithmetic processing unit 8 calculates the measurement time T2, J of the timer 7:
Then, the flow rate bar/L/, the number of X FQ=1, the unit metered volume Fu υ, and the flow rate Q2-yu/T2 are calculated and the results are output, and the counter 6 and timer 7 are reset. Furthermore, when the flow rate becomes smaller or becomes zero and the flow rate pulse time interval becomes extremely long, the processing unit 8 changes the flow rate pulse time interval T measured by the timer 7.
and a predetermined time limit T, )T.

When T>TL, the flow rate is determined to be almost zero, Q=CI is output, and the counter 6, timer 7, memory section 9, and memory device 10i are reset.

Note that a typical arithmetic processing unit 8 is a microcombinator, and the processing procedures related to the arithmetic processing unit detailed above are stored in the built-in l'(OM part).

As described above, according to this embodiment, since the flow rate and measurement time are synchronized, the flow rate per unit time can be calculated accurately, and the single Q rii time measurement opening time is also long in the low flow rate region. Measurement is possible even when the flow rate pulse interval is reached, and furthermore, when the flow rate becomes almost zero and the flow rate pulse interval becomes longer than the '1trll time limit, it is determined to be zero flow rate, and the effect of being able to effectively make a zero determination is completely destroyed.

Effects of the Invention As described above, the flow rate measuring device of the present invention can provide all of the other effects.

(1) The flow rate pulse and measurement time can be synchronized.

(2) By adding C to the effect of (1), it is possible to accurately measure the total flow rate per unit time.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a flow rate measuring device according to an embodiment of the present invention, FIG. 1, C, 2, and P are timing diagrams for explaining the operation of the apparatus shown in FIG. 1...Fluid supply line, 2...Flow rate sensor, 6... Arithmetic processing unit, 6...Counter, 8... Arithmetic processing section , 1o... Memory device as a timer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 to tL t2 31st (smell 110tb tt t2

Claims (1)

[Claims] A flow rate sensor is installed in a fluid supply line and transmits a flow rate pulse every time d1 of a predetermined unit measurement volume of fluid is input, and the flow rate sensor is connected to a flow rate sensor that transmits a flow rate pulse each time a predetermined unit measurement volume of fluid is supplied. an arithmetic processing unit that calculates the flow rate per hour; the arithmetic processing unit includes a counter that counts the number of flow rate pulses; A flow rate measuring device comprising a timer for measuring, and an arithmetic processing section that calculates the total flow rate per unit time from the number of flow pulses measured by the counter and the time measured by the timer.