JPH0545199A - Output method of unit flow signal for leakage inspection in fluidic gas meter - Google Patents

Abstract

PURPOSE:To prevent the misjudgment by the shift of a zero point, by setting the integrated value of a slight unit flow at a specific threshold. CONSTITUTION:A flow signal detected by a flow detecting element 1 is inputted to an operation element 2, the flow operation and the integration is carried out, and the integrated value is displayed on a display element 3. A gas safety cutout 4 inputs one pulse whenever the flow operated by the operation element 2 arrives at the measured value of one half of the threshold, judges abnormal when it comes time to arrive at the threshold per hour, and gives an alarm by shutting a shut-off valve 6 provided to a gas passage 5 or turning on and off an alarm lamp 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention constantly monitors the flow rate of gas flowing in a gas meter, and in the case of a so-called gas safety device that stops gas when there is an abnormality in the flow rate, a leak inspection in a fluidic gas meter. Unit flow rate signal output method.

[0002]

2. Description of the Related Art A gas cutout is for monitoring the usage status of gas by the flow rate of gas flowing through a gas meter and its change and time. A gas leak inspection function is also added to this gas cutout.

This gas leakage inspection is a method of determining that there is a leakage when an inspection flow rate threshold value is set and an integrated flow rate signal is input within a fixed time.

[0004]

However, when a minute signal is measured based on the signal from the microflow sensor and the unit flow rate is integrated, if the 0 point of the microflow sensor shifts, the flow rate signal is generated based on the disturbance. It may be output, and based on this, it may be mistaken for leakage or not.

An object of the present invention is to provide a unit flow rate signal output method for leak inspection in a fluidic gas meter which does not cause misidentification even if the zero point is shifted.

[0006]

The unit flow rate signal output method according to the present invention is as follows.

1. When the unit flow rate signal output for leak inspection in the gas safety device installed in the fluidic gas meter is set to 1/2 of the threshold value, the unit flow rate is set to 1/2 of the threshold value, and when the unit flow rate reaches this integrated value. A method of outputting a unit flow rate signal for leakage inspection in a fluidic gas meter, which outputs a unit flow rate signal to the gas safety device side.

2. The method for outputting a unit flow rate signal for leakage inspection in a fluidic gas meter according to claim 1, wherein the integrated value is set to 1 / 2n of the threshold value, and the leakage determination is performed depending on whether or not n pulses are input within a fixed time.

[0009]

The flow rate signals detected by the micro flow sensor and the fluidic element are input to a calculator, where the flow rate is calculated and integrated, and the integrated value is displayed on the display. At the same time, the flow rate signal detected by the micro flow sensor and the fluidic element is output as one pulse when 1/2 of the threshold value is integrated. Based on this signal, the gas safety device compares the threshold value with the threshold value. The pulse output every time the threshold value is integrated by ½ is monitored for a certain period of time, and if one or more pulses are input during the certain period of time, it is determined that there is leakage.

[0010]

EXAMPLE 1 1 is a flow rate detection part of a fluidic gas meter, which comprises a micro flow sensor and a fluidic element. The flow rate signal detected by the flow rate detection unit 1 is input to the calculation unit 2, where flow rate calculation and integration are performed, and the integrated value is displayed on the display unit 3.

Reference numeral 4 denotes a gas safety device, and one pulse is input to the gas safety device 4 every time the flow rate calculated by the arithmetic unit 3 measures 1.5 liters, and the gas safety device 4 has a threshold value. Compared with 3 liters per hour, when it is within this threshold value, it is judged as normal, and when it is above, it is judged as abnormal and the shut-off valve 6 attached to the gas flow path 5 is closed or the alarm lamp 7 is made to blink and an alarm is issued. Emit.

[0012]

As described above, according to the present invention, the threshold value 1 /
By setting 2 as the unit flow rate signal for leak inspection, the threshold value is set to 3 liters per hour as shown in FIG. 2, and the initial performance set to 0 liters per hour is 1.
Even if it is shifted by 5 liters, a pulse signal is output, so that gas leakage can be detected. On the contrary, since the flow rate pulse is not output even if it is shifted to the + side by 1.5 liters, it is not erroneously recognized as a leak even though it is not flowing. Also, the same effect can be obtained by setting the integrated amount to 0.5 liter and determining whether or not there is a leak for three pulses. Therefore, even if the characteristics of the microflow sensor are shifted due to some reason, there is no fear of misjudgment.

Further, the minute unit flow rate integrated value is set to 1 / th of the threshold value.
By setting the value to 2, it is possible to use a common integrated value regardless of the size of the meter, and therefore, it is possible to use it for gas meters of all sizes and reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is an explanatory diagram when the characteristics of the microflow sensor are shifted.

[Explanation of symbols]

 1 Flow rate detection unit 2 Calculation unit 3 Display unit 4 Gas safety device 5 Gas passage 6 Shutoff valve 7 Alarm lamp

Claims (2)

[Claims] 1. A unit flow rate signal output for leak inspection in a gas safety device mounted on a fluidic gas meter, wherein the integrated value of the minute unit flow rate is set to 1/2 of the threshold value, and the minute unit flow rate is set to this integrated value. A unit flow rate signal output method for leak inspection in a fluidic gas meter, which outputs a unit flow rate signal to the gas safety device side when it becomes. 2. The integrated value is set to 1 / 2n of a threshold value,
2. The unit flow rate signal output method for a leak inspection in a fluidic gas meter according to claim 1, wherein the leak determination is performed depending on whether or not n pulses are input within a fixed time.