JP7724636B2 - Protective cover for detectors, construction management system and attachment/detachment device - Google Patents

Description

The present invention relates to a protective cover for detectors that protects detectors such as fire detectors, a construction management system that uses this protective cover, and a protective cover attachment/detachment device.

Conventionally, when installing fire detectors and other detectors within a building or facility to create a fire alarm system, interior construction work may be carried out before the construction is completed. In order to protect the fire detectors from dust and other particles generated during the construction work, dust covers (protective covers) are attached to the detectors. There is also an invention related to dust covers for such detectors and an attachment/detachment device that allows the dust covers to be attached to installed detectors without using a stepladder (Patent Document 1).

Furthermore, in the past, location information systems have sometimes been installed in addition to fire detection systems within buildings and facilities, and one invention has been to use a fire detector and place an information transmission module (beacon) that transmits location information in a storage compartment inside the decorative cover (detector case) of the detector (Patent Document 2).

Japanese Patent Application Laid-Open No. 2019-21009 Japanese Patent Application Laid-Open No. 2020-126700 JP 2016-148983 A

However, the dustproof cover described in Patent Document 1 is to be removed after the work is completed, and there is a risk of making a mistake by forgetting to remove the dustproof cover.
There is an invention in which a light-emitting unit (LED) is provided at the bottom of the protective cover to prevent forgetting to remove the cover (Patent Document 3). However, when a light-emitting unit is provided at the bottom of the protective cover as in Patent Document 3, although there is an advantage in that it is possible to discover that the cover has been left unremoved, it is necessary to visually check whether the light-emitting unit is emitting light, which requires a person to patrol all areas where sensors are installed to check, which is a heavy burden to check, and there is a risk that areas that should be patrolled will be overlooked, in which case there remains the problem that it will not be possible to discover that the cover has been left unremoved.

On the other hand, the inventors have discovered that even in buildings and facilities where the client does not require a location information system and only wants to install a fire alarm system, a location information system can be used to track the progress of construction work during the installation of the fire alarm system. However, when a storage compartment is provided inside a decorative cover and the detector is placed there, as in the invention described in Patent Document 2, there is a problem in that the information transmission module inside the detector becomes useless after construction, or that it becomes necessary to remove the decorative cover and disassemble and retrieve the information transmission module.

Furthermore, the invention described in Patent Document 2 has the advantage of reducing costs compared to constructing a location information system by installing an information transmission module separately from the detector. However, because the detector is placed in a storage compartment provided inside the decorative cover, there are restrictions on the detectors that can be used with the location information system, resulting in increased detector costs and an increased burden on customers.

The present invention has been made in response to the above-mentioned problems, and aims to provide a protective cover for sensors that can temporarily set up a construction management system to monitor the progress of construction and inspection without incurring a significant increase in costs.
Another object of the present invention is to provide a construction management system that can easily detect when a protective cover for a sensor has been left unremoved after construction.
It is still another object of the present invention to provide a protective cover attacher/detacher that can reliably detect when a protective cover for a detector has been left unremoved after installation.

In order to achieve the above object, the present invention provides:
A protective cover for a detector that can be attached to the surface of a detector installed in a building or facility by engaging with a part of the detector,
a cover body having a cylindrical cup portion with a bottom that covers at least the surface of the sensor from the outside;
a transmitting means for transmitting an information signal wirelessly;
and power supply means for supplying a power supply voltage to the transmitting means.

According to the above configuration, the protective cover attached to the detector is provided with a transmitting means for wirelessly transmitting information signals. Therefore, by attaching a protective cover having a transmitting means to a detector that constitutes a fire alarm system installed in a building or facility, it is possible to temporarily create a construction management system that can protect the detector from dust and the like generated during construction, while also keeping track of the location of workers carrying mobile communication terminals and the progress of construction and inspections.
In addition, since the protective cover attached to the detector is provided with a transmitting means for wirelessly transmitting an information signal, no modifications are required to the detector, which makes it possible to avoid an increase in the cost of the detector.Furthermore, after installation is completed, the protective cover can be removed, collected, and reused, which makes it possible to suppress an increase in the cost of the protective cover.

Preferably, the transmitting means and the power supply means are configured as a unit housed in a single case, and the case is configured to be detachable from the cover body.
With this configuration, the information transmitting unit is detachable from the cover body, so when the sensor is shipped, only the cover body can be attached to the sensor, which reduces costs. Also, if either the cover body or the communication unit is damaged or malfunctions, it becomes possible to replace only one of the parts.

Another invention of the present application is
a detector protective cover having the above-described configuration attached to a surface of a detector constituting a monitoring system installed in a predetermined area of a building or facility;
a mobile communication terminal having a function of receiving an information signal from the transmitting means and a function of wirelessly communicating via a communication network;
a management server capable of communicating with the mobile communication terminal via a communication network;
The management server is configured to grasp the location of the mobile communication terminal based on information received from the transmitting means and device information of the mobile communication terminal.

With the above configuration, by attaching a protective cover with a transmitting means to the sensors that make up the monitoring system installed in buildings and facilities, it becomes possible to determine the location of mobile communication terminals, making it possible to temporarily and inexpensively build a construction management system. Furthermore, by collecting and reusing the protective cover after construction is complete, the costs required to build the system can be reduced.

Also, preferably, the management server
a list indicating the relationship between the work content to be performed by the person accompanying the mobile communication terminal and/or a list indicating the relationship between the work content and the equipment used for the work, in a storage unit;
The system is configured to have a function of grasping the progress of construction and inspection based on the location of the mobile communication terminal and the information in the list.
With this configuration, the locations of not only the workers but also the equipment can be grasped, allowing for more detailed construction management.

Furthermore, preferably, the management server is configured to have the function of determining that the protective cover has been forgotten to be removed when, after construction is completed, the mobile communication terminal accompanying a worker moving within the specified area receives an information signal from the transmitting means of the sensor protective cover.
With this configuration, when the protective cover is retrieved after installation is completed, it is easy to discover that the protective cover has been left unremoved, and the position of the protective cover that has been left unremoved can be easily and reliably determined.

Furthermore, another invention according to the present application is
A detacher used to attach a detector protective cover having the above-described configuration to a surface of the detector installed at a high position in a building or facility,
A bowl-shaped holder attached to the tip of a long operating rod is provided with a receiving means capable of receiving an information signal from the transmitting means and an alarm means which, when receiving an information signal, collects unique information contained in the information signal to identify and alarm any uncollected protective covers.

With the above configuration, the protective cover attachment/detachment device, which has a long operating rod, is provided with a receiving means capable of receiving information signals from the protective cover's transmitting means, so that by bringing the holder at the tip of the operating rod close to the protective cover, it is possible to reliably discover that the protective cover has been left unattached. Furthermore, because the attachment/detachment device has a long operating rod, there is no need to work at heights using a stepladder or the like when attaching or removing the protective cover, thereby improving work efficiency and safety.

The detector protective cover of the present invention makes it possible to temporarily set up a construction management system to monitor the progress of construction and inspection without incurring a significant increase in costs. Furthermore, the construction management system of the present invention makes it easy to discover if a detector protective cover has been left unremoved after construction. Furthermore, the protective cover attacher/detacher of the present invention has the effect of reliably discovering if a detector protective cover has been left unremoved after construction.

1 is a perspective view showing a schematic configuration of an embodiment of a protective cover for a sensor according to the present invention and a sensor; 2A is a cross-sectional view showing the detailed configuration of the sensor protective cover and the sensor in FIG. 1 before attachment, and FIG. 2B is a cross-sectional view showing another example of the configuration of the sensor protective cover. FIG. 2 is a cross-sectional view showing the sensor protective cover and the sensor immediately after attachment. 1 is a system configuration diagram showing an embodiment of a construction management system according to the present invention. This is a diagram showing an example of an equipment drawing (floor diagram) showing the layout of a floor on which terminal devices such as fire detectors, whose addresses are set by an address setting device, are installed.

Hereinafter, embodiments of a protective cover for a sensor, a construction management system using the same, and an attacher/detacher for the protective cover according to the present invention will be described with reference to the drawings.
Fig. 1 shows a perspective view of a detector protective cover and a detector according to the present invention, and Fig. 2 shows a cross-sectional view of the detector and the detector protective cover. The detector shown in Figs. 1 and 2 is a smoke detector.

As shown in Figure 1, the detector 10 comprises a base 11 fixed to the ceiling and a detector main body 12 detachably attached to the base 11. The detector main body 12 has a dome-shaped case main body 13 and a roughly cylindrical head portion 14 protruding downward from the center of the case main body 13.
A plurality of openings 14a are formed on the side of the head portion 14 to allow smoke to enter the interior of the detector 10. In this embodiment, a smoke detector is shown as the detector 10, but other types of fire detectors such as a heat detector or a flame detector may also be used.

As shown in Figures 1 and 2, the protective cover 20 for the sensor of this embodiment comprises a bottomed cylindrical cup portion 21 that covers the head portion 14 of the sensor main body 12, a bottomed annular outer ring portion 22 that surrounds the case main body portion 13 of the sensor main body 12, and a connecting portion 23 that connects the cup portion 21 and the outer ring portion 22, and has an overall shape that corresponds to the outer shape of the sensor 10.
The sensor protective cover 20 is formed to be relatively thin so that it can be elastically deformed by using a resin material.

In addition, the peripheral wall of the cup portion 21 of the sensor protective cover 20 is provided with a plurality (four) of engaging protrusions 21a that protrude inward at predetermined intervals in the circumferential direction, and these engaging protrusions 21a are used to engage with the openings 14a of the head portion 14 of the sensor 10 and attach the sensor protective cover 20 to the sensor 10.
Further, the outer ring portion 22 is formed with reinforcing structures 21b to maintain the three-dimensional shape of the sensor protective cover 20. In this embodiment, four reinforcing structures 21b are provided on the outer surface of the outer ring portion 20 at equal intervals in the circumferential direction.

The protective cover attacher/detacher 50 used to attach and detach the sensor protective cover 20 having the above-described configuration to and from the sensor 10 installed on the ceiling comprises, as shown in Figure 2(A), a bowl-shaped holder portion 51 of a size corresponding to the cup portion 21 of the protective cover 20, and a connecting portion 52 one end of which is fixed to the outer surface (the underside in the figure) of the holder portion 51.
A long operating rod (not shown) can be connected to the other end of the connecting portion 52 (the lower end surface in the figure), and by connecting the operating rod, a worker can use the attachment/detachment device 50 of this embodiment to attach and detach the sensor protective cover 20 to and from the sensor 10 installed on the ceiling C without using a stepladder or the like.

The holder portion 51 has a pair of parallel slits extending vertically downward from the upper end thereof, and a pair of claws 53 extending vertically upward are formed at 180° opposite each other, with the upper end of each claw 53 being elastically deformable in the radial direction. Furthermore, each of the claws 53 has a protrusion 53a protruding inward, which is sized to be able to engage with the outer side of the engaging protrusion 21a of the protective cover 20.
As a result, as shown in Figure 2 (A), with the cup portion 21 of the protective cover 20 placed on the protrusion portion 53a of the holder portion 51 of the detacher 50, the operating rod is lifted to raise the holder portion 51, and the cup portion 21 is engaged with the head portion 14 of the detector 10 attached to the ceiling surface C and pushed up, so that the engaging protrusion portion 21a engages with the opening 14a of the head portion 14 of the detector 10, allowing the detector protective cover 20 to be attached to the detector 10.

To remove the protective cover 20 from the detector 10, as shown in Figure 3, the cup portion 21 of the protective cover 20 is fitted into the holder portion 51 of the detacher 50, and placed over the head portion 14 of the detector 10. With the protrusions 53a of the claws 53 of the holder portion 51 engaged with the outside of the engaging protrusions 21a of the protective cover 20, the operating rod is pulled down to lower the holder portion 51, causing the engaging protrusions 21a to disengage from the opening 14a of the head portion 14 of the detector 10, and the detector protective cover 20 can be removed from the detector 10.

As shown in FIG. 1, the sensor protective cover 20 of this embodiment has an information transmission unit 24 that transmits signals (radio waves) of a predetermined frequency, mounted on the bottom surface of the cup portion 21 of the protective cover 20. As shown in FIG. 2(B), the information transmission unit 24 incorporates a transmission module 24A and a power supply module 24B. The transmission module 24A can use known communication methods, such as Bluetooth (registered trademark) communication or wireless LAN such as Wi-Fi conforming to the IEEE 802.11 standard. The radio wave strength of the transmission modules 24A is preferably such that the communication ranges of adjacent transmission modules 24A touch each other or partially overlap each other.

The information transmission unit 24 may be integrated with the protective cover 20, or, for example, as shown in Figure 2(B), a hook-shaped locking piece 21c may be provided on the bottom surface of the cup portion 21 of the protective cover 20, and an engagement recess 24c that can engage with the locking piece 21c may be provided on the top surface of the bottom surface of the cup portion 21 of the case 24D of the information transmission unit 24, so that the information transmission unit 24 and the protective cover 20 are integrally connected by engaging the locking piece 21c with the engagement recess 24c that can engage with the locking piece 21c. The relationship between the locking piece 21c and the engagement recess 24c may also be reversed, i.e., the locking piece 21c may be provided on the top surface of the case 24D of the information transmission unit 24, and the engagement recess 24c may be provided on the bottom surface of the cup portion 21.

The engaging recess 24c, which can engage with the engaging piece 21c, should be designed so that after the engaging piece 21c is inserted into the end of the engaging recess 24c and engaged, the information transmission unit 24 can be moved to a position where it will not fall out by slightly rotating the cover body 21. This structure is the same as the known structure for fixing a sensor to a sensor base, so a detailed explanation will be omitted.

As described above, by configuring the information transmission unit 24 to be detachable from the main body of the protective cover 20, the protective cover 20 can be shared between detectors to be used in building a construction management system and detectors that will not be used in building a construction management system. Furthermore, when shipping fire detectors, they can be shipped with only the protective cover 20 attached, thereby reducing costs. Furthermore, if either the protective cover 20 or the information transmission unit 24 is damaged or malfunctions, it is possible to address the issue by replacing only one of the parts.

FIG. 4 shows an embodiment of the information transmission unit 24 provided in the sensor protective cover 20 and the configuration of a construction management system using the same.
As shown in Figure 4, the construction management system of this embodiment is composed of an information transmission unit 24, a mobile communication terminal 30 such as a smartphone that receives signals transmitted from the information transmission unit 24, and a management server 40 that is connected to the mobile communication terminal 30 via a communication network (public wireless communication network) NW such as the Internet.

The information transmitting unit 24 of the sensor protective cover 20 includes a transmitting module 24A as a beacon that transmits a signal of a predetermined frequency that includes its own unique information (such as a device ID or facility information), and a power supply module (battery) 24B that supplies power to the transmitting module 24A. It is preferable to use a thin battery such as a button battery for the battery of the power supply module 24B, and it is also preferable to provide a structure in the case 24D of the information transmitting unit 24 that allows the battery to be replaced.
Although not shown, the sensor may also be provided with an on/off switch that enables the operation of the transmitting module 24A, and an indicator light such as an LED that indicates that the power is on. The indicator light is located in a position that can be seen when the protective cover 20 is attached to the sensor.

The mobile communication terminal 30 includes a wireless communication unit 31, a control unit 32 consisting of a CPU, an operation unit 33, a display unit 34, a power supply unit 35, etc., and the wireless communication unit 31 is provided with a receiving means for receiving signals from the transmitting module 24A and a wireless communication means such as LTE or Wi-Fi for communication between the management server 40.
The management server 40 is a computer device, and may be a personal computer, that includes a wireless communication unit 41, a control unit 42 including a CPU, a memory unit (database) 43, and a power supply unit 44. The memory unit (database) 43 stores an equipment drawing (floor diagram) such as that shown in Figure 5, which shows the layout of the floors on which the fire detectors 10A, 10B, 10C, etc. are installed.

In Figure 5, the "D" written within each block 10A, 10B, 10C... representing a detector denotes the type of detector (fire detector), "24h", "25h", "26h"... are the communication addresses assigned to each fire detector, and #01, #02, #03... are the device IDs of the information transmission units 24 attached to the detectors. When installing the detectors, the equipment diagram in Figure 5 is used as a reference and the addresses are set so that the device IDs of the information transmission units 24 correspond to the communication addresses of the fire detectors. Alternatively, an information transmission unit 24 with a device ID corresponding to the address is attached to a detector that already has a communication address set.

In addition to the facility diagram (floor map) shown in Figure 5, the storage unit (database) 43 of the management server 40 also stores a list showing the correspondence between the installed sensors 10 and the attached protective covers 20, as well as a list showing the correspondence between the IDs of all workers in charge of construction and the type of work they are responsible for and the average time required for each task. Furthermore, the management server 40 has the function of referring to the above list to grasp and manage the type of work performed and the progress of construction and inspection, based on the amount of time the workers spent in each area, etc.

In the construction management system of this embodiment, when a worker moves to a specified floor carrying a mobile communication terminal 30 to perform work, the mobile communication terminal 30 receives information transmitted by an information transmission unit 24 attached to a sensor installed on that floor, and transmits the information received from the information transmission unit 24 along with its own terminal ID to the management server 40 via the communication network NW. Therefore, the management server 40 can determine the location of the mobile communication terminal 30 by referencing the information (list) in the memory unit (database) 43. Therefore, a location information system is constructed by each information transmission unit 24, mobile communication terminal 30, and management server 40.

As a result, the management server 40 can determine the location of the worker holding the mobile communication terminal 30 and the type of work they are responsible for based on the information received from the mobile communication terminal 30 and the floor map, and predict whether or not the work has been performed by calculating the time spent on that floor, and based on this, can grasp the progress of construction and inspection. Furthermore, if a device with communication capabilities like the mobile communication terminal 30 is installed on a cart or other device used to transport the equipment needed for construction and the equipment is listed, the management server 40 can more accurately grasp the progress of construction and inspection and manage the equipment.

Furthermore, when all construction is completed, the information transmission units 24 are removed from each detector and collected, and the operation of the transmission module 24A is disabled using an on/off switch or the like. After the collection work is completed, a signal indicating that the collection work is complete is sent to the management server 40 by operating the mobile communication terminal 30, for example, and a worker accompanied by the mobile communication terminal 30 makes the rounds of each floor. Then, if any information transmission units 24 were left behind, the transmitted information from that information transmission unit 24 is received by the mobile communication terminal 30 and sent to the management server 40.
Therefore, when the management server 40 receives the information transmitted from the information transmission unit 24 after the completion of the collection work, it can determine that a unit has been left unremoved. Furthermore, if a procedure is established in which the work of removing the information transmission unit 24 is performed when testing each detector after construction, it can be determined that there are detectors that have not been tested. Note that, while it is particularly preferable to make a patrol after the collection work, in cases where many workers use mobile communication terminals 30 and work is being carried out in various locations, patrol is not necessarily required because the mobile communication terminals 30 will receive the information transmitted from any information transmission unit 24 that has been left unremoved.

As described above, the protective cover and construction management system of this embodiment make it possible to grasp the progress of construction and inspection, and to appropriately manage workers and equipment. Furthermore, after all fire detectors 10 that make up the fire detection system being constructed have been installed, the protective covers 20 and information transmission units 24 are removed from all fire detectors 10 and collected during testing. This allows the protective covers 20 and information transmission units 24 to be reused.

Furthermore, the protective cover of this embodiment makes it easy to discover that an information transmission unit 24 has been left unremoved, and by comparing it with the facility drawing (floor map), it is easy to find the location of the detector to which the forgotten information transmission unit 24 is attached. Another advantage is that there is no need to modify the detector, which avoids any increase in detector costs and does not increase the burden on the customer.

In the above embodiment, the portable communication terminal 30 is used to determine whether the information transmission unit 24 is attached to the installed sensor, but it is also possible to provide a receiver capable of receiving a signal from the information transmission unit 24 of the protective cover 20 on the upper surface of the bottom wall of the holder part 51 at the tip of the operating rod of the detacher 50 as shown in Figure 2, and to provide an indicator lamp or the like on the outer surface of the holder part 51 so that the indicator lamp lights up when a signal is received, thereby making it possible to visually confirm whether the information transmission unit 24 is present or not.
In addition, an indicator lamp or the like may be provided at the lower end of the operating rod of the detachable device 50 and a cable may be routed inside the operating rod, so that the presence or absence of the information transmitting unit 24 can be confirmed at hand.
Furthermore, instead of the indicator lamp, a buzzer or speaker may be provided to notify the user by sound, or a signal may be sent to a portable communication terminal to notify the user.

There are three possible methods for identifying sensors (protective covers) that have been installed using the above-mentioned detachable device 50 equipped with a receiver that can receive signals from the information transmission unit 24: creating a list in advance before installation, collecting each piece of unique information with a mobile communication terminal before installation, and collecting each piece of unique information at the time of installation by using a detachable device. By identifying and storing sensors (protective covers) that have been installed using any of the above methods, and then receiving and comparing the unique information with the detachable device when the sensors are removed, it is possible to identify unrecovered protective covers from the difference.
As a method of notification, for example, a display screen or speaker may be provided on the detachable device 50, and the remaining number may be displayed or notified by voice, or the detachable device 50 may be provided with a communication function with the mobile communication terminal 30, and the remaining number may be displayed as a list or map on the screen of the mobile communication terminal, or may be notified by voice.

In order to realize the above functions, a processing section having a function of identifying uncollected protective covers may be provided in the detachable device 50, the mobile communication terminal 30, or the management server 40. Except for cases where the detachable device 50 has the function of identifying the installation status and also has the function of reporting, the detachable device 50 is provided with a function of communicating with the mobile communication terminal 30.
By configuring the attachment/detachment device 50 as described above, unique information can be collected when using the attachment/detachment device 50 to retrieve the protective cover 20, making it possible to determine the remaining number and location of unrecovered protective covers. This makes it easier to find unrecovered protective covers, prevents them from being forgotten to be removed, and eliminates the need to patrol and check all areas where sensors are installed, thereby reducing the burden of the checking work.

Although the above describes an embodiment of the present invention, the present invention is not limited to the above embodiment and various modifications and variations are possible. For example, in the above embodiment, the information transmission unit 24 is detachably attached to the bottom surface of the protective cover 20, but the protective cover 20 and the information transmission unit 24 may be configured as an integrated unit. Also, while the information transmission unit 24 has been described as having only the function of transmitting information, it may also be configured as a communication unit capable of two-way communication. Furthermore, the information transmission unit 24 may have the function of transmitting information received from the mobile terminal to the management server 40.

Furthermore, in the above embodiment, a fire detector that constitutes a fire alarm system is given as an example of a detector, but the detector to which the protective cover 20 having the information transmission unit 24 is attached is not limited to a fire detector, and may be a detector such as a gas detector or a human presence sensor that constitutes a monitoring system, and the fire detector may be of any detection type, such as a smoke detector or heat detector. Furthermore, this construction management system may be applied after the installation of detectors during construction or after their inspection, as well as when re-attaching and removing protective covers intended to protect the detectors after the inspection.

10 Detector (fire detector)
REFERENCE SIGNS LIST 11 Base 12 Sensor body 13 Case body 14 Head 20 Sensor protective cover 21 Cup 22 Outer ring 23 Joint 24 Information transmission unit 24A Transmission module 24B Power supply module (battery)
30 Portable communication terminal 31 Wireless communication unit 32 Control unit (information processing means)
33 Operation unit 34 Display unit 35 Power supply unit 40 Management server 41 Wireless communication unit 42 Control unit (information processing means)
43 Memory unit (database)
44 Power supply unit 50 Detachable device 51 Holder unit 52 Connecting unit 53 Claw unit

Claims (6)

A protective cover for a detector that can be attached to the surface of a detector installed in a building or facility by engaging with a part of the detector,
a cover body having a cylindrical cup portion with a bottom that covers at least the surface of the sensor from the outside;
a transmitting means for transmitting an information signal wirelessly;
power supply means for supplying a power supply voltage to the transmitting means;
A protective cover for a sensor, comprising: the transmitting means and the power supply means are configured as a unit housed in a single case,
2. The protective cover for a sensor according to claim 1, wherein the case is configured to be detachable from the cover body. a protective cover for a detector according to claim 1 or 2 attached to a surface of a detector constituting a monitoring system installed in a predetermined area of a building or facility;
a mobile communication terminal having a function of receiving an information signal from the transmitting means and a function of wirelessly communicating via a communication network;
a management server capable of communicating with the mobile communication terminal via a communication network;
wherein the management server grasps the location of the mobile communication terminal based on information received from the transmitting means and device information of the mobile communication terminal. The management server
a list indicating the relationship between the work content to be performed by the person accompanying the mobile communication terminal and/or a list indicating the relationship between the work content and the equipment used for the work, stored in a storage unit;
4. The construction management system according to claim 3, further comprising a function for grasping the progress of construction and inspection based on the location of the mobile communication terminal and the information in the list. The construction management system described in claim 3 or 4, characterized in that the management server is configured to have a function to determine that the protective cover has been left unremoved when, after construction is completed, the mobile communication terminal accompanying the worker moving within the specified area receives an information signal from the transmitting means of the sensor protective cover. 3. A detacher used to attach the detector protective cover according to claim 1 or 2 to a surface of the detector installed at a high position in a building or facility,
A detachable device characterized in that a bowl-shaped holder attached to the tip of a long operating rod is provided with a receiving means capable of receiving an information signal from the transmitting means and an alarm means that, when an information signal is received, detects and alarms any unrecovered protective covers by collecting unique information contained in the information signal.