JP7425146B1 - Differential distributed sensor - Google Patents

Abstract

The present invention provides a differential distributed sensor that can be easily tested. [Solution] A differential distributed type sensor 1 that detects a fire by detecting a pressure increase in an air pipe 2 laid in a warning area, the air pipe 2 and the air to which the air pipe 2 is connected. A pipe connection part 4, a pressure sensor 5 that detects the pressure inside the air pipe 2, and an air injection means (test pump) 6 that injects air into the air pipe 2 through the air pipe connection part 4 during a test. It includes a determination processing section 7 that performs a fire determination based on the output value of the pressure sensor 5 and also determines the test result during a test. Inside the air pipe connection part 4, there are a first passage 4e that communicates the first connection hole part 4a and the leak hole part 4d, and a second passageway 4e that communicates the second connection hole part 4b and the test hole part 4c as internal passages. A passage 4f is provided. Both the first passage 4e and the second passage 4f are provided as always fixed passages. [Selection diagram] Figure 1

Description

The present invention relates to a differential distributed sensor.

A differential distributed type sensor is a type of heat sensor that detects a fire by detecting a sudden pressure rise due to thermal expansion of air in an air pipe installed in a monitoring area using a pressure detection means such as a diaphragm. It is something to do.

When inspecting this type of sensor, the following multiple types of tests are performed (for example, see Patent Document 1).
Operation test (pump test): A test to confirm whether the sensor operates normally when a specified amount of air is injected.
Flow test: A test that measures the pressure state when a predetermined amount of air is injected and confirms whether the air pipe is normal.
Diaphragm test: A test to check whether the diaphragm is normal by measuring the pressure state when a predetermined amount of air is injected.
Leak test: A test that measures the pressure state when a predetermined amount of air is injected and confirms whether the leak resistance function is normal.

Japanese Patent Application Publication No. 2014-71474

Conventionally, a test device consisting of a syringe (air injection means) and equipment such as a manometer (pressure gauge) has been used (see Patent Document 1).

When performing the above test using a conventional test device, it was necessary to connect the syringe and manometer on the test device side to the sensor side as a preparatory work. It was also necessary to switch the air passage in the cockstand on the sensor side (the part to which the air pipe of the sensor body is connected).

However, the syringe connection destination and the manometer connection destination differ from test to test, and the switching destination of the air passage also differs from test to test (the switching position of the cock hand differs in terms of operation). Therefore, it was necessary to reconnect test equipment and switch air passages for each test. Furthermore, it was necessary to inject air separately for each test.

Therefore, conventionally, conducting the above test required a large number of steps and was complicated.

In view of the above circumstances, it is an object of the present invention to provide a differential distributed sensor that can be easily tested.

The present invention provides a differential distributed type sensor that detects a fire by detecting a pressure increase in an air pipe installed in a restricted area, the air pipe and an air pipe connection part to which the air pipe is connected. a pressure sensor that detects the pressure within the air pipe; an air injection means that injects air into the air pipe during the test; and a fire determination based on the output value of the pressure sensor. The present invention is a differential distributed type sensor characterized by comprising: a determination processing unit that determines a result.

In this invention, the pressure sensor may be provided between the air pipe and the air pipe connection portion. Further, the pressure sensor may output a measured value of the pressure within the air pipe. Further, the determination processing unit may calculate a pressure increase rate from the measured value of the pressure, and during the test, the test result may be determined by comparing the pressure increase rate with a threshold value. Can be done. Further, the determination processing section may determine whether or not there is a change in the pressure change tendency during the test. Further, the determination processing section may determine whether the pressure reduction width exceeds an appropriate range during the test. Further, the air pipe connecting part has a first connecting hole part to which one end of the air pipe is connected and which communicates with a leak hole part for letting air in the air pipe escape to the outside, and a first connecting hole part of the air pipe. A second connection hole is connected to the other end and communicates with the test hole to which the air injection means is connected, and one end of the air pipe and the first connection hole are provided. A connecting portion connecting the two may be provided between them, and the pressure sensor may be provided in the connecting portion. Further, the connecting portion is provided with an opening/closing portion that opens and closes communication between one end of the air pipe and the first connection hole, and the pressure sensor detects that when the opening/closing portion is closed, The pressure on the air pipe side may be detected. Further, the air pipe connection part includes a first connection hole that communicates with a leak hole that allows air in the air pipe to escape to the outside, and a second connection hole that communicates with a test hole to which the air injection means is connected. are provided, and are located so as to straddle between one end and the other end of the air pipe and between the first connection hole and the second connection hole. A connecting portion may be provided to connect the two, and the pressure sensor may be provided in the connecting portion. Further, the determination processing section may estimate the length of the air pipe. Further, the determination processing section may estimate a standard pressure reduction width from the estimated value of the length of the air pipe.

In the present invention, a test is performed using an air injection means, a pressure sensor, and a determination processing section included in the sensor itself. That is, the sensor itself has a test function. Therefore, when conducting a test, conventionally necessary work such as connecting test equipment can be eliminated, and the number of steps can be reduced.

Therefore, according to the present invention, it is possible to provide a differential distributed sensor that can be easily tested.

1 shows an example of an embodiment of a differential distributed type sensor of the present invention, and is a configuration diagram showing a simplified configuration of the entire sensor. It is an operation flow diagram which simplified the flow of fire detection processing of the sensor same as the above. FIG. 2 is an operation flow diagram showing a simplified test process flow of the sensor same as the above. It shows an example of a configuration change of the same sensor as above, and is a configuration diagram similar to FIG. 1. This is a configuration diagram similar to FIG. 1, showing another example of a configuration change of the same sensor as described above.

Embodiments of the differential distributed sensor of the present invention will be described below with reference to the drawings.

[Equipment configuration]
In FIG. 1, a sensor 1 is an air tube type differential distributed type sensor, and includes an air tube 2 laid in a loop in the monitoring area, and a box-shaped sensor body (generally a detection part In the sensor body, there is an air pipe connection part 4 to which the air pipe 2 is connected, a pressure sensor 5 that detects the pressure inside the air pipe 2, and a pressure sensor 5 that detects the pressure inside the air pipe 2. Based on the output value of the test pump 6 (an example of air injection means) that injects air into the air pipe 2 and the pressure sensor 5, in the event of a fire, a fire judgment is made, and in the case of a test, a test result is judged. It includes a processing section 7 and a transmitting/receiving section (not shown) that transmits and receives signals between the sensor 1 and a fire receiver (not shown), etc., such as sending and receiving judgment results in the judgment processing section 7 .

The air pipe connection part 4 has a first connection hole part 4a to which one end 2a of the air pipe 2 is connected, a second connection hole part 4b to which the other end 2b is connected, and a test pump 6. A test hole portion 4c to be connected and a leak hole portion 4d for letting the air inside the air pipe 2 escape to the outside are provided.

Furthermore, inside the air pipe connecting portion 4, as an internal passage, a first passage 4e that communicates with the first connecting hole portion 4a and the leak hole portion 4d, and a first passage 4e that communicates with the second connecting hole portion 4b and the test hole portion 4c are provided. A second passage 4f is provided. Both the first passage 4e and the second passage 4f are provided as always fixed passages.

Note that the illustrated example shows a case where the pressure sensor 5 and the determination processing section 7 are integrated. Both may be separate and provided separately.

[Fire detection function]
In the sensor 1, when a fire occurs, the pressure sensor 5 detects a sudden pressure rise due to thermal expansion of the air in the air pipe 2, and the determination processing section 7 determines the presence of a fire and outputs a fire signal. , fire detection is performed.

[Test function]
During the test, the test pump 6 injects a predetermined amount of air into the air pipe 2, the pressure sensor 5 detects the pressure change inside the air pipe 2 at that time, and the judgment processing section 7 reports various test results. The test is performed by making a judgment.

In other words, the sensor 1 has not only a fire detection function but also a test function, and can be tested using the equipment included in the sensor 1 itself. Therefore, the work of connecting test equipment, etc., which was conventionally necessary, can be eliminated, and the number of steps can be significantly reduced. Therefore, according to the sensor 1, a test can be easily performed.

[Specific examples of each configuration]
- Pressure sensor The pressure sensor 5 is used for fluid, detects and measures the pressure of the air in the air pipe 2, and outputs it as an electrical signal. The measured value to be output can be a value measured at a constant cycle (or all the time).

- Arrangement of pressure sensor The pressure sensor 5 may be provided between the air pipe 2 and the air pipe connection part 4. In the case of the example shown in FIG. 1, it is provided between one end 2a of the air pipe 2 and the first connection hole 4a. During the test, air is injected into the air tube 2 from the other end 2b side. That is, the pressure sensor 5 detects pressure at a position on the downstream side of the air pipe 2. It may be provided between the other end 2b of the air pipe 2 and the second connection hole 4b, and the pressure may be detected at a position on the upstream side of the air pipe 2. It would be better to detect the pressure at the position, but the pressure would be detected after the test pump 6 injects air and the air flows through the entire air pipe 2, such as when there is a hole in the air pipe 2. This is advantageous in that there is a clear difference in pressure rise, making it easier to find abnormalities.

- Connection Portion The pressure sensor 5 may be provided at the connection portion 8 that connects the air pipe 2 and the air pipe connection portion 4. In the case of the example shown in FIG. 1, it is provided at the connecting portion 8 that connects one end 2a of the air pipe 2 and the first connection hole portion 4a of the air tube connecting portion 4. The connecting portion 8 may be, for example, a joint member having a connecting portion with the air pipe 2 side, a connecting portion with the air pipe connecting portion 4 side, and a connecting portion with the pressure sensor 5 side.

- Judgment processing unit - Fire judgment The judgment processing unit 7 calculates the rate of pressure increase (for example, the percentage of the increase in the measured value with respect to the reference value) based on the measured value of the pressure output from the pressure sensor 5, and It has a function to make a fire judgment by comparing the pressure rise rate value and the pressure rise rate threshold value for fire judgment. As the determination processing section 7, a microcomputer or the like is used.

...Test Judgment Based on the pressure measurement value output from the pressure sensor 5, the judgment processing unit 7 records the measurement value at predetermined intervals (for example, 1 second intervals), calculates the rate of pressure increase, and calculates the pressure increase rate. It has a function to compare the pressure increase rate value with various threshold values and judge various test results.

...Automatic Test The sensor 1 may have a function of automatically switching the operation between monitoring and testing, and may automatically perform the test during operation. The determination processing unit 7 has a function of automatically performing such a test. Specifically, while the sensor 1 is in operation, it has a function that automatically transitions between the monitoring operation process for making fire judgments and the test operation process for making test judgments. It has the function of controlling the operation of the test pump 6. When performing a test, a process is performed to transition to the test operation process at a predetermined timing (such as when a test signal is received from the fire receiver via the transmitter/receiver), and after the automatic test starts, the test pump 6 perform a predetermined operation (such as injecting a predetermined amount of air into the air pipe 2).

Note that instead of or in addition to performing the test automatically, the test may be performed manually at any timing.

... Forced termination of test The sensor 1 may have a function of forcibly terminated the test, considering the possibility that a fire may occur even during the test. The determination processing unit 7 has a function of forcibly terminating such a test. Here, the possibility of a fire occurring during a test is determined by changes in pressure change trends (whether there is a tendency for pressure to increase immediately before the test starts, whether there is a difference between the pressure change trend during the test and the pressure change trend under normal conditions), This can be determined from the presence or absence of a tendency for pressure increase during the test to continue for a certain period of time, etc.). The fluctuation can also be used to determine whether there is an abnormality in the air pipe 2 or the leak hole portion 4d. In other words, the determination processing unit 7 determines that the number of fluctuations in the pressure change tendency is not more than a predetermined number of times, as explained as "(2) Forced termination of automatic test (air pipe or leak hole test)" in the test content described later. If the number of fluctuations exceeds a predetermined number of times, the test is forcibly terminated due to the possibility of a fire outbreak.On the other hand, if the number of fluctuations exceeds a predetermined number, it is determined that there is an abnormality in the air pipe 2 or the leak hole 4d. It has a function to perform judgment processing.

...Estimating the length of the air pipe If the amount of air injected into the air pipe 2 is constant, the longer the air pipe 2 is, the lower the maximum value of the rising pressure will be. That is, the length of the air pipe 2 determines the maximum value of the pressure inside the air pipe 2 when a predetermined amount of air is injected into the air pipe 2. Therefore, the length of the air pipe 2 can be estimated from the maximum value of the measured pressure. The determination processing unit 7 has a function of estimating the length of the air pipe 2. The estimated length of the air pipe 2 can be used to estimate the standard pressure reduction width of the air pipe 2, which will be explained later, but it can also be used to estimate the standard pressure reduction width of the air pipe 2 at the site. It can also be used to understand the state.

... Estimation of the standard pressure reduction width of the air pipe It is possible to estimate the standard pressure reduction width of the air pipe 2 (pressure reduction width when the air pipe 2 is normal) from the estimated value of the length of the air pipe 2. can. The determination processing unit 7 has a function of estimating the standard pressure reduction width of the air pipe 2. Note that the estimated value of the standard pressure reduction width of the air pipe 2 is used to determine the third threshold value for determining the pressure reduction width during "(4) Air pipe or leak hole test" explained later. Can be used.
...Other Functions The determination processing section 7 may have a display function for displaying various test results and the like.

- Test pump As the test pump 6, an electric type is used. For example, an electric air pump or the like can be used.

[Fire detection method]
FIG. 2 shows an example of the flow of the detector 1 during monitoring, up to a fire determination, and the flow of operations up to the transition to automatic testing.

As shown in the figure, after the start of monitoring, in step S1, a reference value of the pressure inside the air pipe 2 is set in order to determine a threshold value for fire determination or as a reference value for the rate of pressure increase during a test. Determine. In step S2, a threshold value for fire determination is determined based on the pressure reference value determined in step S1. In step S3, the determination processing unit 7 acquires a pressure measurement value from the pressure sensor 5. The determination processing unit 7 calculates the rate of pressure increase from the measured pressure value, and then compares the value of the rate of pressure increase with a threshold value for fire determination in step S4 to determine whether or not the rate of pressure increase has increased above the threshold value. Perform judgment processing. If the value has risen above the threshold and the determination is Yes, in step S5, for example, a device with a fire alarm function such as a fire receiver is notified of the occurrence of a fire, and in step S6, a notification of the occurrence of a fire is sent. Perform judgment processing. On the other hand, if the pressure has not risen above the threshold value, the determination process of whether or not there is an abnormality is performed in step S7, and if it is determined as Yes, the process of determining whether there is an abnormality in the pressure sensor 5 is performed. On the other hand, if the determination is No, a determination process is performed in step S9 to determine whether a predetermined time has elapsed. If the predetermined time has not elapsed and the determination is No, the process returns to step S3. On the other hand, if the predetermined time has elapsed and the determination is YES, a determination process is performed in step S10 to determine whether or not to conduct the test. If the test should not be conducted and the answer is No, the process returns to step S1. On the other hand, if it is determined that a test should be performed and the answer is yes, a process of transition to test operation (automatic test) is performed.

[Test method]
・Contents of automatic test (1) Test of air pipe or test pump The judgment processing unit 7 compares the value of the pressure rise rate of the air pipe 2 with the first threshold value for pressure rise judgment, and determines whether there is any pressure rise. Perform the judgment process. If the value of the pressure increase rate does not exceed the first threshold value, it is determined that there is no pressure increase. Here, for example, if the air pipe 11 is clogged or has a large hole, the pressure will not increase. Further, even when the test pump 6 fails, the pressure does not increase. If the pressure does not rise, there is a high possibility that something is wrong with the air pipe 2 or the test pump 6. Therefore, when it is determined that there is no pressure increase, a process is performed to determine whether there is an abnormality in the air pipe 2 or the test pump 6 as a test result.

(2) Forced termination of automatic test (air pipe or leak hole test)
In the determination processing unit 7, before the test (at the time of installation or start of use of the sensor 1, etc.), the pressure change tendency (time change) during normal conditions as a reference is measured and recorded, and this is used as the reference value. A process of determining whether there is a change in the pressure change trend is performed by comparing with the current measured value or by comparing the differentiated results. If there is a fluctuation in the pressure change tendency, a process is performed to determine whether or not the fluctuation occurs a predetermined number of times or more. If the number of fluctuations is not equal to or greater than the predetermined number, there is a possibility that a fire has occurred, and the automatic test is forcibly terminated. If the number of fluctuations is more than a predetermined number of times, there is a high possibility that there is an abnormality in the air pipe 2 or the test pump 6, and therefore, as a test result, a process is performed to determine whether there is an abnormality in the air pipe 2 or the leak hole portion 4d. .

(3) Leak hole test The determination processing unit 7 compares the value of the rate of pressure increase in the air pipe 2 with a second threshold value for determining a pressure decrease, and performs a determination process to determine whether or not there is a pressure decrease. If it does not fall below the second threshold, it is determined that there is no pressure drop. Here, for example, if the leak hole 4d is clogged, the pressure will not easily decrease. If there is no pressure drop, there is a high possibility that there is an abnormality in the leak hole 4d. Therefore, when it is determined that there is no pressure drop, a process is performed to determine whether there is an abnormality in the leak hole portion 4d as a test result.

(4) Testing the air pipe or leak hole The determination processing unit 7 compares the value of the pressure increase rate of the air pipe 2 with the third threshold value for determining the pressure decrease width, and determines whether the pressure decrease width exceeds the appropriate range. A judgment process is performed to determine whether or not the data is rejected. If it is less than the third threshold, it is determined that the pressure reduction width exceeds the appropriate range. Here, for example, if there is a small hole in the air pipe 2 or if the resistance of the leak hole 4d is small, the pressure decrease width becomes large. If the pressure reduction width exceeds the appropriate range, there is a high possibility that there is an abnormality in the air pipe 2 or the leak hole portion 4d. Therefore, when it is determined that the pressure reduction width exceeds the appropriate range, a process is performed to determine whether there is an abnormality in the air pipe 2 or the leak hole portion 4d as a test result.

In addition, the third threshold value for pressure reduction width determination is calculated by calculating the estimated value of the length of the air pipe 2 from the maximum value of the pressure, and calculating the estimated value of the standard pressure reduction width from the estimated value of the length. This can be determined by determining the limit value of the appropriate range from the estimated value of the pressure reduction width.

- Specific example of operational flow during testing FIG. 3 shows an example of operational flow during testing up to automatic test termination (including forced termination).

As shown in the figure, after starting the automatic test, an operation command is given to the test pump 6 in step S1. In step S2, the test pump 6 injects a predetermined amount of air into the air pipe 2, and in step S3, the determination processing section 7 records the measured value of the pressure output from the pressure sensor 5 at predetermined intervals. The determination processing unit 7 calculates the pressure increase rate from the recorded pressure measurement value, and then calculates the pressure increase rate in step S4 as a test of the air pipe 2 or the test pump 6 (test in (1) above). The value of is compared with a first threshold value for determining a pressure increase, and a determination process is performed to determine whether or not there is a pressure increase. If the pressure has not increased and the determination is Yes, a process is performed to determine whether there is an abnormality in the air pipe 2 or the test pump 6 in step S5. On the other hand, if the pressure has increased and the determination is No, in order to conduct further testing, the determination processing unit 7 estimates the piping length of the air pipe 2 from the maximum value of the pressure in step S6, In step S7, a standard pressure reduction width is estimated from the estimated pipe length value. Furthermore, a limit value of the appropriate range is determined from the estimated standard pressure decrease width value, and a third threshold value for pressure decrease width determination is determined. Then, in step S8, the determination processing unit 7 performs the determination process for forced termination of the test (the process in (2) above) in order to be able to respond immediately even if a fire occurs during the automatic test. The current measured value of the pressure change tendency is compared with a reference value to determine whether there is a change in the pressure change tendency. If there is a fluctuation in the pressure change tendency and it is determined as Yes, in step S9, a determination process is performed as to whether or not the number of fluctuations is greater than or equal to a predetermined number of times, and if the number of fluctuations is not greater than a predetermined number of times, it is determined as No. If it is determined that there is a possibility of a fire occurring, intermediate processing is omitted and automatic test termination processing is performed. On the other hand, if the number of fluctuations is greater than or equal to a predetermined number and the determination is YES, in step S10, a process is performed to determine whether there is an abnormality in the air pipe 2 or the leak hole portion 4d. If there is no change in the pressure change trend and the determination is No in the determination process of step S8, there is no possibility of fire occurring, and the test is continued and the leak hole portion 4d is tested (test in (3) above). In step S11, the value of the rate of pressure change is compared with a second threshold value for determining a pressure drop to determine whether or not there is a pressure drop. If the pressure has not decreased and the determination is Yes, a process is performed to determine whether there is an abnormality in the leak hole portion 4d in step S12. On the other hand, if the pressure has decreased and the determination is No, the pressure change rate value is reduced in step S13 as a test for the air pipe 2 or the leak hole 4d (test in (4) above). A process is performed to determine whether the pressure reduction width exceeds an appropriate range by comparing it with a third threshold value for width determination. If the pressure reduction width exceeds the appropriate range and the determination is YES, a process is performed to determine whether there is an abnormality in the air pipe 2 or the leak hole portion 4d in step S14. On the other hand, if the pressure reduction width does not exceed the appropriate range and the determination is No, then in step S15, it is determined that everything is normal, and the process of ending the automatic test is performed.

[Example of configuration change]
The embodiments of this invention have been described above with reference to FIGS. 1 to 3, but the specific configuration is not limited to the above embodiments, and design changes may be made without departing from the gist of this invention. It further includes changes in the.

- Addition of a flow opening/closing mechanism to the connecting part For example, as for the connecting part 8, as shown in FIG. An opening/closing part 9 may be provided to open and close communication between the pressure sensor 5 and the pressure sensor 5 when the opening/closing part 9 is closed and the flow between the air pipe 2 side and the air pipe connecting part 4 side is blocked. It may be provided so as to detect the pressure on the air pipe 2 side when the air pipe 2 is being operated.

As a result, when an abnormality is determined in the test of the air pipe 2 or the leak hole 4d in (4) above, the opening/closing part 9 is closed (normally, the test is performed with the opening/closing part 9 open). ), by repeating the same test as in (4) above and determining whether there is an abnormality in the air pipe 2, it is possible to determine whether the abnormality is in the air pipe 2 or the leak hole 4d. Become.

- Straddling the connecting part Furthermore, as shown in FIG. The pressure sensor 5 can be provided so as to straddle between the hole 4a and the second connection hole 4b to connect these four parts, and the pressure sensor 5 can be connected to the connection part 8 that is provided astride the hole 4a and the second connection hole 4b. may be provided.

1: Sensor 2: Air pipe 2a: One end 2b: Other end 4: Air pipe connection part 4a: First connection hole part 4b: Second connection hole part 4c: Test hole part 4d: Leak hole part 4e: First passage 4f: Second passage 5: Pressure sensor 6: Test pump 7: Judgment processing section 8: Connection section 9: Opening/closing section

Claims (4)

A differential distributed type sensor that detects a fire by detecting a pressure increase in an air pipe installed in a restricted area,
the air pipe;
an air pipe connection part to which the air pipe is connected;
a pressure sensor that detects the pressure within the air pipe;
an air injection means for injecting air into the air pipe through the air pipe connection part during the test;
a determination processing unit that performs a fire determination based on the output value of the pressure sensor and determines a test result during a test;
The pressure sensor outputs a measured value of the pressure within the air pipe,
The determination processing unit calculates a rate of pressure increase from the measured value of the pressure, and during the test, compares the rate of pressure increase with a threshold value to determine the test result,
Further, the differential distribution type sensor is characterized in that the determination processing section determines whether or not there is a change in pressure change tendency during a test. A differential distributed sensor that detects fire by detecting a pressure rise in air pipes installed in a restricted area,
the air pipe;
an air pipe connection part to which the air pipe is connected;
a pressure sensor that detects the pressure within the air pipe;
an air injection means for injecting air into the air pipe through the air pipe connection part during the test;
a determination processing unit that performs a fire determination based on the output value of the pressure sensor and determines a test result during a test;
The pressure sensor outputs a measured value of the pressure within the air pipe,
The determination processing unit calculates a rate of pressure increase from the measured value of the pressure, and during the test, compares the rate of pressure increase with a threshold value to determine the test result,
Further, the differential distribution type sensor is characterized in that the determination processing section determines whether or not the pressure reduction width exceeds an appropriate range during a test. A differential distributed sensor that detects fire by detecting a pressure rise in air pipes installed in a restricted area,
the air pipe;
an air pipe connection part to which the air pipe is connected;
a pressure sensor that detects the pressure within the air pipe;
an air injection means for injecting air into the air pipe through the air pipe connection part during the test;
a determination processing unit that performs a fire determination based on the output value of the pressure sensor and determines a test result during a test;
One end of the air pipe is connected to the air pipe connection part, and a first connection hole part that communicates with a leak hole part for letting air in the air pipe escape to the outside, and the other end of the air pipe are connected to the air pipe connection part. a second connection hole portion to which the end portion is connected and communicates with the test hole portion to which the air injection means is connected;
The pressure sensor is provided between one end of the air pipe and the first connection hole, and is provided at a connecting portion that connects the two,
The connecting part is provided with an opening/closing part that opens and closes communication between one end of the air pipe and the first connection hole of the air pipe connecting part,
The differential distribution type sensor is characterized in that the pressure sensor detects pressure on the air pipe side when the opening/closing part is closed. A differential distributed sensor that detects fire by detecting a pressure rise in air pipes installed in a restricted area,
the air pipe;
an air pipe connection part to which the air pipe is connected;
a pressure sensor that detects the pressure within the air pipe;
an air injection means for injecting air into the air pipe through the air pipe connection part during the test;
a determination processing unit that performs a fire determination based on the output value of the pressure sensor and determines a test result during a test;
The differential type distributed sensor is characterized in that the determination processing section estimates the length of the air pipe.

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