JP2743746B2 - Gas supply equipment abnormality detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting an abnormality in a gas supply equipment for detecting an abnormality in a gas pressure regulator and a gas leak from a gas supply pipe.

[0002]

2. Description of the Related Art Conventionally, in order to prevent an explosion accident due to a gas leak or a fire accident due to forgetting to turn off a gas appliance, a gas meter monitors the use time of the gas appliance and the gas appliance for a long time. If the gas appliance was continued to be used, it was determined that the gas appliance was forgotten to be turned off, and a gas shut-off device for stopping gas supply was incorporated. With this device, safety in gas use was secured from the gas meter to the downstream side.

On the other hand, on the upstream side of a gas meter, for example, LP
In the case of gas, regarding the safety management from the cylinder to the gas meter, an operator goes to the site at a predetermined time (eg, once every two years) to perform a safety check. FIG. 7 is a block diagram of a safety check method on the upstream side of a meter in a conventional gas supply facility. In FIG. 7, 1 is an LP gas cylinder, 2 is a main stopper of the cylinder, 3 is a gas pressure regulator, 4
Denotes a gas meter, 5 denotes a gas combustion instrument, 6 denotes a gas pressure measuring instrument, 7 denotes a gas pipe branching section, 8 denotes a high pressure side pipe section, and 9 denotes a low pressure side pipe section.

[0004] In the conventional gas supply equipment configured as described above, an operator goes to the site and connects a gas pressure measuring device 6 in the middle of the gas pipe between the gas pressure regulator 3 and the gas meter 4 to connect the gas pipe. The internal gas pressure was being measured. In checking the gas pressure regulating ability of the gas pressure regulator 3, the main valve 2 of the LP gas cylinder and the gas shut-off valve in the gas meter 4 are opened, and the gas pressure measuring instrument 6 sets the gas combustion instrument 5 in a normal use state. Was measured. When the measured gas pressure is a predetermined value (for example, 230 to 330 (mm
If it was during H2O)), it was normal, and if not, it was determined that the pressure regulator had failed. Further, in checking the gas closing pressure adjusting capability of the gas pressure regulator 3, the pressure when the gas combustion device 5 is stopped from the combustion state is measured by the gas pressure measuring device 6, and a predetermined value (for example, 350 (mm)
H2O)), it was determined to be normal if it was below, and if it exceeded, it was determined that the occlusion pressure was abnormal.

[0005]

However, in the above configuration, it is necessary for an operator to go to the site and install a gas pressure check device to check the safety, which is troublesome and time-consuming, and cannot be monitored constantly. There was a problem that.

The present invention solves such a conventional problem, and automatically checks an obstruction pressure from a signal of a gas pressure sensor when the gas supply equipment is abnormal, that is, when gas use is stopped, and adjusts the gas pressure. It is a first object of the present invention to provide a gas supply equipment abnormality detection device capable of detecting an abnormality of a closing pressure function of a vessel.

Further, according to the present invention, even if it is determined that the occlusion pressure has exceeded the reference value, the count is reset only when a state where the occlusion pressure does not exceed the reference value is detected only once, and the count is reset. It is a second object of the present invention to provide a gas supply facility abnormality detection device which can be used.

Further, according to the present invention, when the gas flow rate is detected,
Moreover, it is a third object of the present invention to provide a gas supply equipment abnormality detection device capable of counting when the state in which the closing pressure exceeds the reference value continues.

It is a fourth object of the present invention to provide a gas supply equipment abnormality detecting device capable of counting when it is determined that the closing pressure exceeds a reference value.

Further, according to the present invention, when the gas flow rate is detected,
A fifth object of the present invention is to provide a gas supply facility abnormality detecting device capable of counting when it is determined that the closing pressure exceeds a reference value.

[0011]

Means for Solving the Problems In order to solve the above problems and achieve the first object, a gas supply equipment abnormality detecting device according to the present invention comprises a gas supply equipment provided downstream of a gas pressure regulator. A gas pressure detecting means for detecting a gas pressure, a gas flow rate detecting means for detecting a gas flow rate flowing through the gas supply equipment, and a signal (Pc) from the gas pressure detecting means when the use of gas is stopped. Closing pressure storing means, comparing reference value generating means for generating a reference value (Ps) for comparing the gas pressure at the time of the closing, and comparing the gas pressure value (Pc) stored in the closing pressure storing means with the comparison Comparing means for comparing and judging the reference value (Ps) of the reference value generating means, counting means for counting according to a signal from the comparing and judging means, and alarm means for issuing an alarm by a signal from the counting means. Is

In order to achieve the second object, according to the present invention, in addition to the above-mentioned structure, the comparing and judging means includes a gas pressure value (Pc) stored in the occlusion pressure storing means and a reference of the comparing reference value generating means. The values (Ps) are compared, and the former (Pc) is compared with the latter (Ps)
When the value does not exceed the value, a signal for resetting the counting of the counting means is outputted, and the counting means resets the counting in response to the reset signal from the comparing and judging means.

According to a third aspect of the present invention, in addition to the above configuration, the counting means includes a first counting section and a second counting section.
The first counting unit is constituted by a counting unit, and the first counting unit counts up when a state where there is a flow rate signal from the gas flow rate detecting means at least once and there is no reset signal from the comparing and determining means reaches a first set value. Is output to the second counting section, and the second counting section counts with the signal from the first counting section and outputs a count-up signal to the alarm means when the second set value is reached,
The first counting section and the second counting section reset the counting by the reset signal from the comparing and judging means.

In order to achieve the fourth object, according to the present invention, in addition to the above-mentioned structure, the comparing and judging means may be arranged so that the gas pressure value (Pc) stored in the occlusion pressure storing means and the reference of the comparative reference value generating means are compared. The values (Ps) are compared, and the former (Pc) is compared with the latter (Ps).
s), a signal is output, and the counting means continues counting by receiving the signal from the comparing and judging means.

According to a fifth aspect of the present invention, in order to achieve the fifth object, the counting means includes a third counting unit and a fourth counting unit.
A third counting unit which counts up the count-up signal when the signal from the gas flow rate detecting means reaches a third set value when the signal indicating the presence of the flow rate from the gas flow rate detecting means is present at least once; The fourth counting section counts with the signal from the third counting section, and outputs a count-up signal to the alarm means when the count reaches a fourth set value.

[0016]

According to the present invention, when the gas flow detecting device detects a state in which the gas combustion appliance is used and the use thereof is stopped, that is, a state in which the gas flow is exhausted thereafter, the signal is received by the above configuration. The closing pressure storage means stores the signal of the gas pressure detecting means when the gas flow is stopped as the closing pressure. Then, the comparison determination means compares the reference value of the comparison reference value generation means with the signal stored in the closing pressure storage means,
The counting means performs counting according to the determination result. As a result, when the count reaches a predetermined value, a signal is sent to the alarm means to alarm as an abnormality of the closing pressure function of the gas pressure regulator,
The alarm means issues an alarm in response to the signal.

In the present invention, the comparison determining means compares the gas pressure value (Pc) stored in the closing pressure storage means with the reference value (Ps) of the comparison reference value generating means, and the former (Pc) is compared with the latter (Pc). When Ps is not exceeded, a signal for resetting the counting of the counting means is outputted, and the counting means resets the counting in response to the reset signal from the comparing and judging means. However, when the former (Pc) exceeds the latter (Ps), that is, while the reset signal does not come, the counting means continues counting, and when the counted value reaches a predetermined value, a signal is sent to the warning means. To send an alarm.

Further, according to the present invention, the first counting section reaches the first set value in a state where the flow rate signal from the gas flow rate detecting means is present at least once and the reset signal is not received from the comparing / determining means. At this time, the counting up signal is output to the second counting section. Then, the second counting section counts with the signal from the first counting section, and outputs a count up signal to the alarm means when the second set value is reached, and issues an alarm. By the way, the first counting section and the second counting section reset their respective counts by the reset signal from the comparing and judging means.

Next, according to the present invention, the comparison judgment means compares the gas pressure value (Pc) stored in the occlusion pressure storage means with the reference value (Ps) of the comparison reference value generation means, and the former (Pc) is used as the latter. When (Ps) is exceeded, a signal is output, and the counting means receives the signal from the comparing and judging means and continues counting. As a result, when a predetermined count value is reached, an alarm is issued.

According to the present invention, the third counting section includes a counting up signal when the signal indicating the presence of the flow rate from the gas flow rate detecting means is present at least once and the signal from the comparing and determining means reaches the third set value. Is output to the fourth counting section. The fourth counting unit is
The counting is performed by the signal from the third counting unit, and when the count reaches the fourth set value, a count-up signal is output to the alarm unit, and an alarm is issued.

[0021]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) In FIG. 1, a gas supply facility abnormality detecting device 17 of the present invention is a gas pressure detection means 10 for detecting the gas pressure of a gas supply facility provided downstream of the gas pressure regulator 3. A gas flow detecting means 11 for detecting a gas flow rate flowing through the gas supply equipment; and a signal (P) from the gas pressure detecting means 10 when the use of gas is stopped.
c), a reference pressure generating means 13 for generating a reference value (Ps) for comparing the gas pressure at the time of closing, and a gas stored in the closing pressure storing means 12. Pressure value (Pc) and comparison reference value generating means 1
3. Comparison judgment means 14 for comparing and judging the reference value (Ps) of No. 3
And counting means 15 for counting in accordance with a signal from the comparing and judging means 14, and an alarming means 16 for issuing an alarm by a signal from the counting means 15. In addition, components having the same numbers as those in FIG. 7 have the same functions.

In the above configuration, when the gas appliance is used and stopped, the gas flow rate detecting means 11 detects the stoppage of the gas use, and upon receiving this detection signal, the closing pressure storage means 12 detects the gas pressure when the gas use is stopped. The detection value of the means 10 is stored. Then, the comparison determination means 14 compares the reference value of the comparison reference value generation means 13 with the signal stored in the closing pressure storage means 12, and the counting means 15 counts according to the determination result. As a result, when the count reaches a predetermined value, the counting means 15 sends a signal to the warning means 16 to warn of an abnormality in the closing pressure function of the gas pressure regulator 3, and the warning means 16 receives the signal and gives a warning. Emits.

Here, the counting means 15 may start counting (counting the number of times or measuring time) when gas is used, that is, when the gas flow rate is detected. The counting may be started when a counting start signal other than the above is received. Then, when the count reaches a predetermined value, a signal is output to the alarm means 16 to issue an alarm.

FIG. 2 shows a change in the detected value of the gas pressure detecting means 10 when the gas flow is stopped from the gas flow stop state and when the gas flow state is shifted to the stop state. The horizontal axis indicates the elapsed time, and the vertical axis indicates the gas pressure value. The dashed line indicates a reference value (P
s). The detected pressure is indicated by a solid line and a dashed line, and the detected value is p1 until the time t0 when the gas flow is stopped, the detected value is p2 when the gas is used from the time t0 to t1, and the gas is detected after the time t1. In the stopped state, the detected pressure at the time t1 is determined as the reference value as the closing pressure. Here, two cases (L1 and L2) are shown. In the case of L1, the detected pressure value is pc1, which is smaller than the comparison reference value ps. In the case of L2, the detected pressure value is pc2 and exceeds the comparison reference value ps. The case of L2 is determined as an obstruction pressure abnormality.

As described above, according to the gas supply equipment abnormality detecting device 17 of the present invention, the abnormality of the gas supply equipment can be automatically detected without the worker visiting the site where the gas meter is installed.
That is, it is possible to detect an abnormality in the closing pressure control performance of the gas pressure detecting means 3.

(Embodiment 2) The configuration of the apparatus for detecting abnormality of gas supply equipment of the present invention is the same as that of FIG. Here, the comparison determination means 14 compares the gas pressure value (Pc) stored in the occlusion pressure storage means 12 with the reference value (Ps) of the comparison reference value generation means 13, and the former (Pc) replaces the latter (Ps). If not exceeded, a signal for resetting the counting of the counting means 15 is output.
When the counting means 15 receives the reset signal from the comparing and judging means 14, the counting which has been continued is reset. That is, when L2 at time t1 shown in FIG. 2, the detected pressure value is pc2 and exceeds the comparison reference value ps, so that the comparison judgment means 14 does not output any signal. Further, when L1 at time t1 shown in FIG. 2, the detected pressure value is pc1 and does not exceed the comparison reference value ps.
The comparison and determination means 14 outputs a reset signal. In response to the reset signal, the counting means 15 resets the count value which has been counted.

As described above, according to the gas supply equipment abnormality detecting device of the present invention, even if it is determined that the closing pressure exceeds the reference value, it is not determined that the closing pressure is abnormal only once, and the closing pressure does not exceed the reference value. Since the count is reset when is detected,
Occasionally, the detection pressure at the time when the ambient temperature is blocked high due to the high ambient temperature can reduce the probability of erroneous determination when the state continues to be high, and the blocking function is reduced due to the aging of the gas pressure regulator. Even in the vicinity of a certain critical point, it is possible to make a decision when it cannot be used reliably.

(Embodiment 3) In FIG. 3, in a gas supply equipment abnormality detecting apparatus 21 of the present invention, a counting means 20 is composed of a first counting section 18 and a second counting section 19. Others
Components having the same numbers as those in FIG. 1 have the same functions.

In the above configuration, the first counting unit 18 determines that the first set value is reached when the flow rate signal from the gas flow rate detecting means 11 is present at least once and the reset signal from the comparing / determining means 14 is absent. Then, the counting up signal is output to the second counting unit 19. The second counting section 19 counts with the signal from the first counting section 18 and outputs a counting up signal to the alarm section 16 when the count value reaches the second set value. here,
The first counting section 18 and the second counting section 19 reset their respective counts when the reset signal from the comparison / determination means 14 is input.

This operation will be described with reference to FIG. In the figure, the horizontal axis indicates elapsed time, and the vertical axis (1) indicates the gas flow rate, (2) indicates the blocking pressure, (3) indicates the counting state of the first counting section, and (4) indicates the counting state of the second counting section. The state is shown. In the gas flow rate of (1),
The bar-shaped portion indicates a state where the gas flow rate is present. When the gas flow is exhausted, that is, when the use of the gas is stopped, the gas pressure is determined to be the reference value as the closing pressure. This determination result is shown in (2). The location indicated by the black circle is the occlusion pressure value. If it is above the dashed line ps indicating the reference value, it is determined that the occlusion pressure is abnormal, and if it is below it, it is normal.

In the counting state of the first counting section of (3), the first counting section
Is reached at time T1, at which point a counting signal is issued. That is, as can be seen from (1), there is no state in which the gas flow rate exists once or more, and the closing pressure value that generates the reset signal from (2) is lower than the reference value, that is, there is no normal state. In response to the counting signal, the second counting section performs counting. This situation is shown in (4). The broken line (4) indicates a state where the counting is valid. Next, the period from the time T1 to the time T2 is a period in which the count in the first counting unit reaches the first set value, as described above.
As can be seen from (1), since there is no gas flow rate, no count signal is sent to the second counting section even when the first set value is reached. Therefore, the second counting section does not perform counting, and maintains the counting state at the time T1. Subsequently, a count signal is sent from the first counting unit to the second counting unit from time T2 to time T3 in the same manner as in the period from time T1. And time T
In 4, since the state in which the occlusive pressure value is lower than the reference value, that is, the normal state, is detected in (2), the counts of the first counting unit and the second counting unit are reset. In this figure, T4
Thereafter, both the first counting section and the second counting section have started counting immediately. Thereafter, between time T4 and time T5, and at time T
Between the time 5 and the time T6, there is a gas flow rate, and there is no normal state of the closing pressure. Therefore, the first counting section and the second counting section continue counting as described above. This state continues,
A signal is issued when the count in the second counting section reaches the second set value, and the alarm means 16 issues an alarm.

As described above, according to the gas supply equipment abnormality detecting device 21 of the present invention, the gas flow rate is detected, and it is possible to count when the state where the closing pressure exceeds the reference value is continued. An alarm can be issued when it is detected that the closing pressure control function of the pressure regulator has stopped working.

(Embodiment 4) The configuration of the present invention is the same as that of FIG. 3, except that the first counting section 18 has a flow rate signal from the gas flow rate detecting means 11 at least once,
When the state where there is no reset signal from 4 reaches 24 hours, a count up signal is output to the second counting section 19.

The reason why the first set value of the first counting section 18 is set to 24 hours is that attention is paid to the fact that the cycle of a person's life pattern is one day, that is, 24 hours. The usage pattern of the gas combustion equipment naturally depends on the life cycle, and the change in the environmental temperature also fluctuates in the same cycle. Therefore, by counting this period as one unit, an alarm can be issued in synchronism with daily life when a failure of the gas pressure regulator is reliably determined.

(Embodiment 5) In FIG. 5, in the gas supply equipment abnormality detecting device 24 of the present invention, the comparison judgment means 22 determines the gas pressure value (Pc) stored in the closing pressure storage means 12 and the comparison reference value generation means. Thirteen reference values (Ps) are compared, and when the former (Pc) exceeds the latter (Ps), a signal is output, and the counting means 23 receives the signal from the comparison determining means 22 and performs counting. . In addition, components having the same numbers as those in FIG. 1 have the same functions.

In the above configuration, the counting means 23 sends a signal to the alarm means 16 to issue an alarm when the count value reaches a predetermined value. As described above, according to the gas supply facility abnormality detection device 24 of the present invention, it is possible to reliably count the case where the blocking pressure exceeds the reference value, and to issue an alarm when the count value reaches a preset count value.

(Embodiment 6) In FIG. 6, in a gas supply facility abnormality detecting apparatus 28 of the present invention, a counting means 27 is constituted by a third counting section 25 and a fourth counting section 26. Others
Components having the same numbers as those in FIG. 1 have the same functions.

In the above arrangement, the third counting section 25 counts up the signal when the flow rate signal from the gas flow rate detecting means 11 is present at least once and the signal from the comparing and determining means 14 reaches the third set value. Is output to the fourth counting section 26, and the fourth counting section 26 counts using the signal from the third counting section 25, and outputs a count-up signal to the alarm section 16 when the count value reaches the fourth set value.

As described above, according to the gas supply equipment abnormality detecting device 28 of the present invention, the gas flow rate is detected, and when the state where the closing pressure exceeds the reference value occurs a predetermined number of times, counting is performed. , For example, when it reaches 30 days, it is possible to determine that it has been detected that the closing pressure control function of the gas pressure regulator has not reached its purpose, and to issue an alarm.

[0041]

As described above, according to the gas supply equipment abnormality detecting device of the present invention, the following effects can be obtained.

(1) Occlusion pressure storage means for storing a signal (Pc) from the gas pressure detection means when the use of gas is stopped, and a reference value (P) for comparing the gas pressure at the time of occlusion.
s), a comparison and determination means for comparing the gas pressure value (Pc) stored in the closing pressure storage means with the reference value (Ps) of the comparison reference value generation means,
Counting means for counting in accordance with a signal from the comparison determination means,
The alarm means issues an alarm in response to a signal from the counting means. Therefore, there is no need for an operator to go to the site and install a gas pressure check device to check the safety, and automatically check the abnormality of the gas supply equipment, that is, the signal of the gas pressure sensor when the gas use is stopped. By checking the closing pressure, it is possible to detect an abnormality in the closing pressure function of the gas pressure regulator.

(2) Even if it is determined that the occlusion pressure has exceeded the reference value, it is not determined to be abnormal only once, and the count is reset when a state where the occlusion pressure does not exceed the reference value is detected. When the ambient temperature is high and the detected pressure at the time of the blockage is high, the probability of erroneous determination when the state continues to be high can be suppressed low, and the critical function whose blocking function is decreasing due to the aging of the gas pressure regulator. Even in the case of a point near, a determination can be made when it cannot be used reliably.

(3) Since the counting can be performed when the gas flow rate is detected and the blocking pressure continues to exceed the reference value, the blocking pressure control function of the gas pressure regulator does not reliably function. An alarm can be issued when it is detected that an error has occurred.

Also, note that the cycle of a person's life pattern is a unit of one day, that is, 24 hours, and the pattern of use of gas-burning equipment naturally depends on the life cycle.
Since the change in the environmental temperature also fluctuates in the same cycle, by counting this period as one unit, the failure of the gas pressure regulator can be reliably determined in synchronization with daily life.

(4) The comparison judgment means compares the gas pressure value (Pc) stored in the closing pressure storage means with the reference value (Ps) of the comparison reference value generation means, and outputs a signal when Pc exceeds Ps. Since the counting means receives the signal from the comparing and judging means and performs counting, it can reliably count the case where the occlusion pressure exceeds the reference value, and can issue an alarm when the count value reaches a preset value. .

(5) Counting is performed when the gas flow rate is detected and the blocking pressure exceeds the reference value for a predetermined number of times, and when it reaches the fourth set value, the gas pressure regulator is blocked. An alarm can be issued when it is determined that the pressure control function is no longer useful.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a gas supply equipment abnormality detection device according to an embodiment of the present invention.

FIG. 2 is a graph showing a gas pressure change characteristic in the apparatus.

FIG. 3 is a functional block configuration diagram of a gas supply equipment abnormality detection device according to another embodiment of the present invention.

FIG. 4 is a graph showing a change characteristic of a gas flow rate and an obstruction pressure in the apparatus and a counting state in which first and second counting units are missing.

FIG. 5 is a functional block configuration diagram of a gas supply facility abnormality detection device according to another embodiment of the present invention.

FIG. 6 is a functional block configuration diagram of a gas supply facility abnormality detection device according to another embodiment of the present invention.

FIG. 7 is a block diagram of a conventional gas supply system for checking safety.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 gas pressure detecting means 11 gas flow rate detecting means 12 closing pressure storing means 13 comparison reference value generating means 14, 22 comparison determining means 15, 20, 23, 27 clocking means 18 first counting section 19 second counting section 25 third counting Unit 26 Fourth counting unit 16 Alarm means 17, 21, 24, 28 Gas supply equipment abnormality detection device

Claims (6)

(57) [Claims] A gas pressure detecting means for detecting a gas pressure of a gas supply facility provided downstream of the gas pressure regulator; a gas flow rate detecting means for detecting a gas flow rate flowing through the gas supply facility; When the use is stopped, a closing pressure storing means for storing a signal (Pc) from the gas pressure detecting means, and a reference value (P) for comparing the gas pressure at the time of closing.
s), a comparison / determination means for comparing a gas pressure value (Pc) stored in the closing pressure storage means with a reference value (Ps) of the comparison reference value generation means, An abnormality detecting device for gas supply equipment, comprising: counting means for counting in accordance with a signal from a comparing and judging means; and alarm means for issuing an alarm by a signal from the counting means. 2. The comparison / judgment means compares the gas pressure value (Pc) stored in the occlusion pressure storage means with a reference value (Ps) of a comparison reference value generation means, and the gas pressure value (Pc) is set to the reference value. 2. The gas supply equipment abnormality detecting device according to claim 1, wherein a signal for resetting the counting of the counting means is output when the difference does not exceed (Ps), and the counting means resets the counting in response to the reset signal from the comparing and judging means. 3. The counting means comprises a first counting section and a second counting section. The first counting section has a flow rate signal from the gas flow rate detecting means at least once and a reset signal from the comparing and judging means. When the state where there is no data reaches a first set value, a count-up signal is output to the second counting section, and the second counting section counts with the signal from the first counting section to reach the second set value. When the counting up signal is output to the alarm means,
3. The gas supply equipment abnormality detecting device according to claim 2, wherein the first counting section and the second counting section reset their respective counts by a reset signal from the comparison / determination means. 4. The first counting section counts up a signal when the state of a signal indicating a flow rate from the gas flow rate detecting means is present at least once and no reset signal from the comparing and determining means has been reached for 24 hours. 4. The gas supply equipment abnormality detection device according to claim 3, wherein the abnormality is output to a section. 5. The comparison judging means compares the gas pressure value (Pc) stored in the closing pressure storage means with a reference value (Ps) of a comparison reference value generating means, and the gas pressure value (Pc) is compared with the reference value (Pc). 2. The gas supply equipment abnormality detecting device according to claim 1, wherein a signal is output when the value exceeds Ps), and the counting means receives the signal from the comparison determining means and continues counting. 6. The counting means comprises a third counting section and a fourth counting section. The third counting section has a flow rate signal from the gas flow rate detecting means at least once and a signal from the comparing / determining means. When the count value reaches a third set value, a count up signal is output to the fourth count unit. The fourth count unit counts with the signal from the third count unit, and counts up when the count value reaches the fourth set value. 6. The abnormality detecting device for gas supply equipment according to claim 5, wherein the signal is output to an alarm means.