JP2021163061A - CO2 sensor system - Google Patents

Abstract

To provide a CO2 sensor system that can reduce power consumption of a CO2 sensor.SOLUTION: A CO2 sensor system 1 comprises a CO2 sensor 20 and a sensor slave unit 10. The sensor slave unit 10 includes a power supply unit, a switch unit for switching whether or not to supply electric power from the power supply unit to the CO2 sensor, and a slave unit control unit for transmitting interval information to the CO2 sensor 20. The CO2 sensor 20 includes: a CO2 measuring unit that measures CO2 concentration; a non-volatile memory that stores a measurement result obtained by the CO2 measuring unit and an elapsed time obtained by integrating the interval information; and a sensor control unit that transmits the measurement result to the sensor slave unit 10. The sensor control unit is configured to execute a correction of the CO2 measurement unit when the elapsed time stored in the non-volatile memory becomes a set value or more of a predetermined correction execution interval.SELECTED DRAWING: Figure 1

Description

The present invention relates to a CO ₂ sensor system.

Patent Document 1 _{discloses a CO 2} sensor system _{that measures the CO 2} concentration in the target space. This CO ₂ sensor system starts introducing outside air after no one is detected in the target space, and _{sets the CO 2} concentration measured when a predetermined time has elapsed as a provisional reference value. This makes it possible to correct the measured _{CO 2} concentration value in a state of being ventilated to some extent. Such _{correction of the CO 2} concentration measurement value is necessary to maintain the measurement accuracy by _{the CO 2 sensor.}

JP-A-2017-156116

When correcting the measured CO ₂ concentration value, it is indispensable to grasp information on time such as the time elapsed from the first start-up, the time elapsed from the time of the previous correction, or the time elapsed since no person was detected. In order to grasp the elapsed time, for example, when a part (Real Time Clock module or the like) capable of measuring time is built in the _{CO 2 sensor, it is necessary to constantly supply electric power to the part.} As a result, there is a problem that the power consumption of _{the CO 2 sensor increases.}

The present invention has been made in view of such circumstances, and an object thereof is to provide a CO ₂ sensor system that can suppress the power consumption of the CO ₂ sensor.

In order to solve the above problems, the CO ₂ sensor system according _{to one aspect of the present invention includes a CO 2} sensor and a sensor slave unit, and the sensor slave unit uses a power supply unit and power from the power supply unit to obtain the CO. has a switch portion for switching whether to supply to the _second sensor, and the apparatus controller for transmitting the distance information to the CO ₂ sensor, the said CO ₂ sensor, CO ₂ measuring unit for measuring the CO ₂ concentration A non-volatile memory that stores the measurement result by the CO ₂ measurement unit and the elapsed time obtained by integrating the interval information, and a sensor control unit that transmits the measurement result to the sensor slave unit. After the switch unit _{starts supplying power to the CO 2} sensor, the sensor control unit cuts off the power supply to the _{CO 2 sensor when the sensor control unit transmits the CO 2} concentration to the sensor slave unit. The sensor control unit is configured to execute the correction of the _{CO 2} measurement unit when the elapsed time stored in the non-volatile memory becomes equal to or greater than a set value of a predetermined correction execution interval. There is.

According to this aspect, the period in which CO ₂ sensor is not performing measurement of the CO ₂ concentration, since the power supply to the CO ₂ sensor is cut off, it is possible to reduce the power consumption. Then, the elapsed time can be obtained by accumulating the interval information in the non-volatile memory in which the stored contents are not lost even when the power of _{the CO 2 sensor is turned off.} As a result, for example, the CO ₂ sensor has a portion where the time can be measured, and it is possible to perform correction based on the elapsed time without constantly supplying power to the portion.

Here, the CO ₂ sensor system of the above aspect may further include a sensor master unit that wirelessly communicates with the sensor slave unit, and a management device connected to the sensor master unit via a network.

Further, the management device may be configured to transmit correction mode information regarding the correction mode to the CO _{2 sensor via the sensor master unit and the sensor slave unit.}

Further, the CO ₂ sensor may have a mode switching unit capable of switching the correction mode, and the mode switching unit may be a physical switch.

Further, the sensor control unit is _{configured to perform correction of the CO 2} measuring unit based on the correction mode, and in the correction mode, the set value and the sensor slave unit execute wireless communication. Whether or not to allow this may be included.

Further, the sensor control unit is _{configured to perform correction of the CO 2} measurement unit based on the correction mode, and the correction mode is used for correction of the _{CO 2} concentration measured by the _{CO 2 measurement unit.} Reference values may be included.

According to this aspect of the present invention, it is possible to provide a CO ₂ sensor system that can suppress the power consumption of the CO ₂ sensor.

It is the schematic of the CO _{2 sensor system of 1st Embodiment.} It is a block diagram which shows the structure of the sensor slave unit and CO _{2 sensor of 1st Embodiment.} It is a flowchart of the control content of the handset control unit and the sensor control unit of 1st Embodiment. It is a flowchart of the initialization process of FIG. It is a flowchart of the correction process of FIG. It is a block diagram which shows the structure of the sensor slave unit and CO _{2 sensor of 2nd Embodiment.} It is a flowchart of the correction process of 2nd Embodiment. It is a flowchart of the control content of 3rd Embodiment. It is a flowchart of the control content of the slave unit control unit and the sensor control unit of the third embodiment.

(First Embodiment)
Hereinafter, the CO ₂ sensor system of the first embodiment will be described with reference to the drawings.
As shown in FIG. 1, the CO ₂ sensor system 1 includes a plurality of sensor units 2, a sensor master unit 3, and a management device 4. The number of sensor units 2 may be one or three or more. Each sensor unit 2 includes a sensor slave unit 10 and a CO ₂ sensor 20. Wireless communication is performed between the sensor slave unit 10 of each sensor unit 2 and the sensor master unit 3. The means of wireless communication include, for example, communication by 920 МHz band specific low power radio, communication based on specifications defined by 3GPP (LTE Cat.M1, Cat.NB1, etc.), Bluetooth (registered trademark), and Wifi (IEEE802.11). And so on. Wired communication (for example, serial communication) is performed between the sensor slave unit 10 and the CO _{2 sensor 20.} Communication is performed between the sensor master unit 3 and the management device 4 via a network such as the Internet. The network may be configured in either wired or wireless form. The sensor unit 2, the sensor master unit 3, and the management device 4 may be arranged in different buildings.

The management device 4 is, for example, a computer or server arranged in a room (management room, guard room, etc.) that manages a building, or a virtual server on the Internet. The sensor master unit 3 functions as a repeater when the management device 4 communicates with the sensor unit 2, and is, for example, a wireless router, a gateway, a base station, or the like.
The sensor unit 2 is installed in a room or the like (hereinafter referred to as a target space) for which _{the CO 2 concentration is to be measured.} The sensor slave unit 10 and the CO ₂ sensor 20 may be connected by wire while being installed in different rooms.

As shown in FIG. 2, the sensor slave unit 10 includes a power supply unit 11, a wireless communication unit 12, a switch unit 13, a slave unit control unit 14, a timer 15, and two internal sensors 16. ing.
The CO ₂ sensor 20 includes a power feeding unit 21, a sensor control unit 22, a non-volatile memory 23, and a CO ₂ measuring unit 24.

The power supply unit 11 is a power supply source for driving the sensor slave unit 10 and the CO _{2 sensor 20.} The power supply unit 11 is electrically connected so that power can be supplied to the wireless communication unit 12, the switch unit 13, the slave unit control unit 14, the timer 15, and the internal sensor 16. Further, the power supply unit 11 is electrically connected to the power supply unit 21 of the _{CO 2 sensor 20 via the switch unit 13.} The power supply unit 11 includes an energy harvesting unit 11a, a power storage unit 11b, a battery 11c, and an external power supply unit 11d.

The energy harvesting unit 11a is a portion that uses natural energy to generate electricity. A solar cell or the like can be adopted as the energy harvesting unit 11a. The power storage unit 11b is, for example, a capacitor (lithium ion capacitor or the like) or a secondary battery (lithium ion battery or the like), and stores the electric power generated by the environmental power generation unit 11a. The battery 11c is, for example, a primary battery, and may function as a backup for the energy harvesting unit 11a and the power storage unit 11b. The external power supply unit 11d is a portion to which power is supplied from the outside of the sensor slave unit 10. The external power feeding unit 11d is, for example, a USB port or an outlet plug. The external power supply unit 11d may distribute the electric power supplied from the outside to other components of the sensor slave unit 10 or the CO ₂ sensor 20 as it is, or may store the electric power in the power storage unit 11b.

The wireless communication unit 12 is a portion that performs wireless communication with the sensor master unit 3. Further, the wireless communication unit 12 may perform wireless communication with the wireless communication unit 12 of another sensor slave unit 10. The wireless communication unit 12 transmits _{the measurement result of the CO 2} sensor 20 and the measurement result of the internal sensor 16 to the sensor master unit 3. Further, the wireless communication unit 12 may receive control information or the like from the sensor master unit 3 or another sensor slave unit 10. The wireless communication unit 12 may be configured to be able to shift to a sleep mode (low power consumption mode) during a period during which wireless communication is not performed.

The switch unit 13 is electrically connected to the power feeding unit 21. The switch unit 13 is configured to switch whether or not to supply the electric power supplied from the power supply unit 11 to _{the power supply unit 21 of the CO 2 sensor 20.} If the switch unit 13 is ON, power is supplied to the power supply unit 21 to _{activate the CO 2} sensor 20. If the switch unit 13 is OFF, the power supply to the power supply unit 21 is cut off and the power of the CO ₂ sensor 20 is turned off.

The slave unit control unit 14 is electrically connected to the sensor control unit 22. The slave unit control unit 14 performs serial communication (I2C: Inter-Integrated Cuircuit, UART: Universal Asynchronous Receiver Transmitter, SPI: Serial Peripheral Interface, etc.) with the sensor control unit 22. The slave unit control unit 14 is configured to control the wireless communication unit 12, the switch unit 13, the internal sensor 16, the sensor control unit 22, and the like. As the slave unit control unit 14, a microcontroller or the like can be used.

The slave unit control unit 14 is operated by being supplied with electric power from the power supply unit 11. The slave unit control unit 14 _{sleeps the operation mode of the sensor slave unit 10 from the active mode when the sensing using the CO 2} sensor 20 or the internal sensor 16 is not performed or when the wireless communication unit 12 does not perform the communication operation. It is configured to be switchable to a mode (low power consumption mode). Further, the slave unit control unit 14 is configured to detect an interrupt signal from the timer 15, the wireless communication unit 12, and the like, and to switch the operation mode of the sensor slave unit 10 from the sleep mode to the active mode.

The timer 15 is configured to generate an interrupt signal at a predetermined timing based on measurement time interval information (hereinafter, simply referred to as interval information) and output it to the slave unit control unit 14. The interval information is information regarding a time interval in which the _{CO 2 concentration is measured by the CO 2} measuring unit 24. For example, when the interval information is "5 minutes", the timer 15 outputs an interrupt signal to the slave unit control unit 14 every 5 minutes. The slave unit control unit 14 is configured to activate the _{CO 2 sensor 20 each time it receives an interrupt signal to measure the CO 2} concentration.
As the internal sensor 16, a temperature sensor, a humidity sensor, an illuminance sensor, or the like can be adopted. The number of internal sensors 16 may be one or three or more. Further, the internal sensor 16 may be omitted.

The power supply unit 21 distributes the electric power received from the power supply unit 11 via the switch unit 13 to the sensor control unit 22, the CO ₂ measurement unit 24, and the like. The power feeding unit 21 may include a load switch and an element (DC / DC converter or the like) that performs voltage conversion.

The sensor control unit 22 controls the CO ₂ measurement unit 24 and is configured to store and read various data in the non-volatile memory 23. As the sensor control unit 22, a microcontroller or the like can be used.
The non-volatile memory 23 is configured to store various data. Even if _{the power of the CO 2} sensor is turned off, the data stored in the non-volatile memory 23 is not lost. As the non-volatile memory 23, for example, EEPROM or FRAM (registered trademark) can be adopted.

The CO _{2 measuring unit 24 measures the CO 2} concentration in the target space by, for example, an NDIR (Non Dispersive InfraRed) method. The CO ₂ measuring unit 24 is controlled by the sensor control unit 22. The CO ₂ measurement unit 24 may include an AD converter, and _{may convert the measurement data of the CO 2} concentration from an analog value to a digital value.
The measurement result of the _{CO 2} concentration by the CO ₂ measuring unit 24 may deviate from the _{actual CO 2 concentration with the passage of time.} Therefore, as CO ₂ concentration measurement results approach the actual CO ₂ concentration, it is necessary to correct the regular CO ₂ measuring section 24.

Next, the flow of control executed by the slave unit control unit 14 and the sensor control unit 22 will be described with reference to FIG.
When power is supplied from the power supply unit 11 of the sensor slave unit 10 to the slave unit control unit 14 and the like, the power supply of the sensor slave unit 10 is turned on (step S1). When the power of the sensor slave unit 10 is turned on, the slave unit control unit 14 starts the initialization process S2.

FIG. 4 shows a detailed flow of the initialization process S2. When the initialization process is started (step S101), the initialization of the wireless communication unit 12 (step S102) and the initialization of the internal sensor 16 (step S103) are executed.
Next, the switch unit 13 is switched from OFF to ON (step S104), power is supplied to the power feeding unit 21, and the power supply of the CO ₂ sensor 20 is turned ON (step S105).

Next, the slave unit control unit 14 transmits the initial setting information to the sensor control unit 22 (step S106). When the sensor control unit 22 receives the initial setting information (step S107), the sensor control unit 22 resets the correction data stored in the non-volatile memory 23 (step S108). The data related to the correction includes the elapsed time T, the _{minimum CO 2} concentration value (hereinafter referred to as the minimum value L), the correction status, and the like. More specifically, in step S108, the elapsed time T is set to 0, the minimum value L is set to an initial value (eg 5000 ppm) that is sufficiently higher than the _{CO 2 concentration that can actually occur, and the correction status is set to incomplete.} Will be done.

Next, the sensor control unit 22 transmits the initial setting completion information to the slave unit control unit 14 (S109). Upon receiving the initial setting completion information (step S110), the slave unit control unit 14 determines whether or not the initial setting has been completed normally.
When the initial setting is normally completed, the sensor control unit 22 _{turns off the power of the CO 2} sensor by switching the switch unit 13 to OFF (step S111) (step S112).
If the initial setting has not been completed normally, the initial setting may be retried (steps S106 to S110).

As shown in FIG. 3, after the initialization process S2 is completed, the slave unit control unit 14 turns on the switch unit 13 (step S3) and _{turns on the power of the CO 2} sensor 20 (step S4).
Next, the slave unit control unit 14 transmits the interval information to the sensor control unit 22 (step S5). The interval information is an interval of time when the _{CO 2 sensor 20 measures the CO 2} concentration in the target space. For example, if the interval information is 5 minutes, the CO ₂ sensor 20 _{measures the CO 2} concentration in the target space every 5 minutes. Subsequently, the slave unit control unit 14 transmits the measurement request to the sensor control unit 22 (step S6).

The sensor control unit 22 receives the interval information (step S7), and subsequently receives the measurement request (step S8). It should be noted that the sensor control unit 22 may consider that the measurement request has also been received by receiving the interval information. In this case, steps S6 and S8 are unnecessary.
Upon receiving the measurement request, the sensor control unit 22 _{acquires the measurement result of the CO 2} concentration in the target space from the _{CO 2} measurement unit 24 and stores it in the non-volatile memory 23 (step S9). Next, the sensor control unit 22 executes the correction process S10.

FIG. 5 shows a detailed flow of the correction process S10. When the correction process S10 is started (step S201), the sensor control unit 22 updates the elapsed time T stored in the non-volatile memory 23 (S202) based on the interval information. Specifically, the numerical value of the interval information is added to the stored elapsed time T. For example, in the case of the interval information of 5 minutes and the first correction process S10 after the initialization process S2 is performed, the elapsed time T is zero, so the numerical value of the interval information is added to "5". "Minute" is the elapsed time T after the update. After that, when the second correction process S10 is performed, 5 + 5 = 10 minutes is the elapsed time T after the update. By accumulating the interval information in this way, the elapsed time T can be obtained.

Next, the sensor control unit 22 compares the elapsed time T with the predetermined set value (step S203). The set value is a time interval (hereinafter, referred to as a correction execution interval) for executing the correction _{of the CO 2 measuring unit 24.} For example, if the set value of the correction execution interval is "7 days", _{the correction of the CO 2} measuring unit 24 is executed every week, and the minimum value of the measurement result of _{the CO 2 concentration in the week is described later.} The correction is performed assuming that it is equal to the reference value R.

The set value of the correction execution interval may be stored in the non-volatile memory 23, or may be stored in another part. If the elapsed time T is smaller than the set value of the correction execution interval, the correction status is set to incomplete (step S204), and _{the calculation process of the CO 2} concentration is executed (step S205). In step S205, the calculated value of the _{CO 2} concentration is calculated by using the measured values of _{the plurality of CO 2 concentrations measured continuously.} The calculated value is, for example, the average value or the median value of a plurality of measured values. In this way, by using the calculated values based on a plurality of measured values, _{even if the measurement variation of the CO 2} measuring unit 24 is large, the variation can be canceled and the CO ₂ concentration close to the reality can be obtained. can.

Next, the sensor control unit 22 _{compares the calculated value of the CO 2} concentration with the minimum value L stored in the non-volatile memory 23. When the calculated value is smaller than the minimum value L, the minimum value L is updated to the calculated value and stored in the non-volatile memory 23 (S207). After that, the correction process S10 ends, and the process proceeds to step S11 in FIG.

In step S203, when the elapsed time T is equal to or greater than the set value of the correction execution interval, the sensor control unit 22 _{executes the correction of the CO 2} measurement unit 24 (S208). Specifically, it is considered that the minimum value L of the measurement result of the _{CO 2} concentration stored in the non-volatile memory 23 is equal to the reference value R of the _{CO 2 concentration, and the subsequent measurement results of the CO 2} measurement unit 24 are corrected. do. Here, the reference value R is, for example, the CO ₂ concentration in the atmosphere (generally 400 ppm). Since the minimum value L is the minimum value of the CO ₂ concentration measured within a certain period of time, it is considered that the influence of _{CO 2} emission due to human breathing in the target space is small and close to _{the CO 2 concentration in the atmosphere.} Be done. Therefore, by considering the minimum value L to be equal to the reference value R, the _{measurement accuracy by the CO 2} measuring unit 24 can be maintained. Depending on the circumstances of the target space, since CO ₂ concentration may not drop to a value in the air, the reference value R may not necessarily be a CO ₂ concentration in the atmosphere.

Next, the sensor control unit 22 resets the elapsed time T and the minimum value L of the _{CO 2 concentration (step S209).} Specifically, similarly to step S108 in the initialization process S2, the elapsed time T stored in the non-volatile memory 23 is set to zero, and the minimum value L is set to the above-mentioned initial value.
Next, the sensor control unit 22 sets the correction status to “complete” (step S210), ends the correction process S10, and proceeds to step S11 in FIG.

In step S11 of FIG. 3, the sensor control unit 22 _{transmits the CO 2} sensor data to the slave unit control unit 14. For the CO ₂ sensor data, _{in addition to the measurement result by the CO 2} measuring unit 24, the correction status, the presence or absence of an error, and whether _{or not to allow the sensor slave unit 10 to transmit the CO 2} sensor data to the sensor master unit 3. Information, etc. can be included.

When the slave unit control unit 14 receives the CO ₂ sensor data (step S12), the slave unit control unit 14 turns off the switch unit 13 (step S13). As a result, _{the power supply to the CO 2} sensor 20 is cut off, and the power of the CO ₂ sensor 20 is turned off (step S14).
Next, the slave unit control unit 14 acquires the data of the internal sensor 16 (step S15). If the internal sensor 16 is not mounted, step S15 may be omitted. Alternatively, step S15 may be skipped when wireless communication of _{CO 2 sensor data is not permitted.}

Next, the slave unit control unit 14 outputs a command to the wireless communication unit 12 and causes the sensor master unit 3 to wirelessly transmit _{the CO 2 sensor data (step S16).} If _{wireless communication of CO 2} sensor data is not permitted, the slave unit control unit 14 can omit step S16. The sensor master unit 3 transmits CO ₂ sensor data to the management device 4 via the network.
Next, the slave unit control unit 14 shifts the operation mode of the sensor slave unit 10 from active to sleep (step S17). As a result, the power consumption of the sensor slave unit 10 can be suppressed.

After a predetermined time based on the interval information has elapsed, the timer 15 outputs an interrupt signal to the slave unit control unit 14. When the interrupt signal is input (step S18), the slave unit control unit 14 shifts the operation mode of the sensor slave unit 10 from sleep to active (step S19).
After that, the process returns to step S3, and the slave unit control unit 14 and the sensor control unit 22 repeatedly execute steps S3 to S19.

As described above, the CO ₂ sensor system 1 _{of the present embodiment includes a CO 2} sensor 20 and a sensor slave unit 10. The sensor slave unit 10 includes a power supply unit 11, a switch unit 13 for switching whether or not to supply _{power from the power supply unit 11 to the CO 2} sensor 20, and a slave unit control unit 14 for transmitting interval information to the _{CO 2 sensor 20.} And have. The CO ₂ sensor 20 has _{a CO 2} measuring unit 24 that measures the _{CO 2} concentration, a non-volatile memory 23 that stores the elapsed time T obtained by integrating the measurement results and interval information by the _{CO 2 measuring unit 24, and the measurement.} It has a sensor control unit 22 that transmits the result to the sensor slave unit 10. Then, after the switch unit 13 _{starts supplying power to the CO 2} sensor 20 (step S3), when the sensor control unit 22 _{transmits the CO 2} concentration to the sensor slave unit 10, the _{switch unit 13 supplies the power to the CO 2} sensor 20. _{The sensor control unit 22 is configured to shut off (step S13), and the sensor control unit 22 corrects the CO 2} measurement unit 24 when the elapsed time T stored in the non-volatile memory 23 becomes equal to or greater than the set value of the predetermined correction execution interval. Is configured to execute (steps S203, S208).

With such a configuration, the period in which CO ₂ sensor 20 is not performing the measurement of the CO ₂ concentration, since the power supply to the CO ₂ sensor 20 is interrupted, it is possible to reduce the power consumption. Then, the elapsed time T is obtained by accumulating the interval information in the non-volatile memory 23 in which the stored contents are not lost even when the power of the _{CO 2 sensor 20 is turned off.} As a result, for example, the CO ₂ sensor 20 has a part (Real Time Clock module, etc.) that can measure the time, and it is possible to perform correction based on the elapsed time T without constantly supplying power to the part. Become.

Further, the CO ₂ sensor system 1 further includes a sensor master unit 3 that wirelessly communicates with the sensor slave unit 10 and a management device 4 that is connected to the sensor master unit 3 via a network. By performing wireless communication via the sensor master unit 3, _{the measurement result of the CO 2} concentration by the sensor unit 2 can be displayed on the management device 4, and a command can be transmitted from the management device 4 to the sensor unit 2. ..

(Second Embodiment)
Next, the second embodiment according to the present invention will be described, but the basic configuration is the same as that of the first embodiment. Therefore, the same reference numerals are given to the same configurations, the description thereof will be omitted, and only the different points will be described.
As shown in FIG. 6, the CO ₂ sensor 20A of the present embodiment has a mode switching unit 25.

The mode switching unit 25 is a physical switch such as a rotary switch or a DIP (Dual In-line package) switch. _{The CO 2} sensor 20 of the present embodiment is configured to switch the correction mode by operating the mode switching unit 25. Table 1 below shows an example of the correction mode. The contents of each correction mode may be stored in the non-volatile memory 23, or may be stored in another storage unit included _{in the CO 2 sensor.}

In Table 1, the column of "reference value R" is in the range of 400 to 600 ppm. Since the CO _{2 concentration in the atmosphere is generally about 400 ppm, the CO 2} concentration in the target space drops to 400 ppm when the target space is sufficiently ventilated after no one is left. Therefore, when the _{target space in which the CO 2} sensor 20 is installed is sufficiently ventilated, it is preferable to select the correction mode numbers 1, 6 and 11 having the reference value R of 400 ppm. On the other hand, _{if it is known in advance that the CO 2} concentration in the target space does not decrease to 400 ppm, another mode number may be selected.

In Table 1, the “Set value” column shows the set value of the correction execution interval of _{the CO 2 measuring unit 24 (see step S203).} For example, in the case of correction mode numbers 1 to 5, the correction of the CO ₂ measuring unit 24 is executed every 10 minutes.
In Table 1, the column of "wireless transmission" means whether or not the wireless communication unit 12 is permitted to perform wireless transmission to the sensor master unit 3. For example, in the correction mode numbers 1 to 5, wireless transmission is not permitted, so that wireless transmission from the wireless communication unit 12 to the sensor master unit 3 is not performed.

Since the set value of the correction mode numbers 1 to 5 is 10 minutes, the correction can be executed in a short time. Therefore, when the CO ₂ sensor system 1 is installed, for example, it is suitable for the purpose of confirming the measurement accuracy while comparing the value measured by the _{CO 2} concentration reference device with the value _{measured by the CO 2 measuring unit 24.} There is. Further, at this time, the interval information from the sensor slave unit 10 can be set to a very short time such as several seconds, but the wireless transmission is "not permitted", so that the power consumption of the wireless communication unit 12 can be reduced and the power consumption of the wireless communication unit 12 can be reduced. Communication congestion can be avoided. Since the power consumption of the correction mode numbers 1 to 5 is larger than that of the other correction modes, the external power supplied from the external power supply unit 11d may be used, or the power supply unit 11 has a primary battery. In some cases, the primary battery may be used.

In the present embodiment, the correction process S10A is executed instead of the correction process S10 in FIG. FIG. 7 shows the details of the correction process S10A. In the correction process S10A, the correction setting is executed after the start of the correction process (step S201) and before the step S202 (step S208). In step S208, the sensor control unit 22 is set to acquire the content of the correction mode number designated by the mode switching unit 25 and execute the subsequent processing according to the content. For example, when the correction mode number 1 in Table 1 is specified in the mode switching unit 25, the set value in step S203 is set to 10 minutes, and the reference value R in step S208 is set to 400 ppm. Further, the sensor control unit 22 transmits the acquired content of the correction mode to the slave unit control unit 14 together with the _{CO 2 sensor data in step S11.} When the correction mode number 1 is selected, the wireless transmission is "not permitted", so the slave unit control unit 14 skips step S16 in FIG. Other points are the same as those in the first embodiment.

As described above, the sensor control unit 22 of the present embodiment is configured _{to perform correction of the CO 2} measurement unit 24 based on the correction mode (step S10A), and in the correction mode, the CO ₂ measurement unit 24 is set. The set value of the correction execution interval and whether or not the sensor slave unit 10 is allowed to execute wireless communication are included. As a result, for example, when the sensor unit 2 is installed, the correction is executed in a short time without performing wireless communication (step S208), and after the installation, the correction is executed at a certain long interval and the result is transmitted to the management device 4 by wireless communication. Can be displayed.

Further, the correction mode of the present embodiment includes a reference value R used for correcting _{the CO 2} concentration measured by the _{CO 2 measuring unit 24.} Thus, when the CO ₂ concentration in the target space is found not to drop to the CO ₂ concentration in the atmosphere, and the reference value R is set to a value higher than the CO ₂ concentration in the atmosphere, more accurately CO ₂ It is possible to correct the measurement result of the measuring unit 24.

Further, since the CO ₂ sensor 20 has a mode switching unit 25 capable of switching the correction mode and the mode switching unit 25 is a physical switch, the mode switching operation can be performed directly at the installation site of the _{CO 2 sensor 20.} It can be carried out.

(Third Embodiment)
Next, the third embodiment according to the present invention will be described, but the basic configuration is the same as that of the second embodiment. Therefore, the same reference numerals are given to the same configurations, the description thereof will be omitted, and only the different points will be described.
In the second embodiment, the correction mode is switched by the mode switching unit 25 which is a physical switch, but in the present embodiment, the correction mode is switched by the software switch. Therefore, the CO ₂ sensor 20 of the present embodiment does not have to have the mode switching unit 25.

In the present embodiment, the management device 4 transmits the correction mode information to the CO ₂ sensor 20 via the sensor master unit 3 and the sensor slave unit 10. The correction mode information is information regarding the correction mode described in the second embodiment. For example, the user can operate the management device 4 and manually input the contents of the correction mode (for example, the reference value R, the set value, etc.), so that the contents of the correction mode included in the correction mode information can be arbitrarily set. It becomes. In this case, it is not necessary to store the data related to the correction mode as shown in Table 1 in the CO _{2 sensor 20 in advance.} However, the correction mode information may specify a specific correction mode number from among a plurality of correction modes stored in _{the CO 2 sensor 20.} In this case, the correction mode information may not include the content of the correction mode itself.

FIG. 8 shows a flow from the transmission of the correction mode information by the management device 4 to the reception by the sensor slave unit 10. First, the management device 4 transmits the correction mode information to the sensor master unit via the network (step S301). When the sensor master unit 3 receives the correction mode information (step S302), the sensor master unit 3 wirelessly transmits the correction mode information to the sensor slave unit 10 (step S303).

The wireless communication unit 12 receives the correction mode information (step S304). At this time, when the slave unit control unit 14 is in the sleep mode, the wireless communication unit 12 generates an interrupt signal and transmits it to the slave unit control unit 14 (step S305). Upon receiving the interrupt signal, the slave unit control unit 14 actively switches the operation mode (step S306). After that, the slave unit control unit 14 saves the correction mode information in the storage unit included in the sensor slave unit 10 (step S307), and switches the operation mode to sleep (step S308). If the slave unit control unit 14 receives the correction mode information (step S304) in the active mode, steps S305, S306, and S308 are skipped.

FIG. 9 shows a flow from when the correction mode information is stored in the storage unit of the sensor slave unit 10 until the correction process is actually performed. The flow shown in FIG. 9 is different from the flow of FIG. 3 in that the points including steps S20 and S21 and the correction process S10A of the second embodiment are executed instead of the correction process S10. Other points are the same as the flow of FIG.

As shown in FIG. 9, the slave unit control unit 14 transmits the correction mode information to the sensor control unit 22 (step S20) after turning on the switch unit 13 (step S3). When the sensor control unit 22 receives the correction mode information (step S21), the sensor control unit 22 stores the content of the correction mode included in the correction mode information in the _{storage unit included in the CO 2} sensor 20. This storage unit may be the non-volatile memory 23 or another storage unit.
After that, the sensor control unit 22 performs the correction process S10A based on the content of the correction mode. Since the details are the same as those in the second embodiment, they will be omitted.

As described above, in the present embodiment, the management device 4 is configured to transmit the _{correction mode information regarding the correction mode to the CO 2 sensor 20 via the sensor master unit 3 and the sensor slave unit 10.} As a result, the correction mode can be switched by remote control. In addition, the content of the correction mode (reference value R, correction execution interval setting value, etc.) can be set more flexibly.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, the correction mode may include only one or two of the correction execution interval setting value, wireless communication permission, and reference value R. Alternatively, other contents (interval information, etc.) may be included in the correction mode.
Further, the mode switching unit 25 (physical switch) described in the second embodiment and the software switch described in the third embodiment may be used in combination. In this case, the correction mode can be switched by using the physical switch at the time of installation, and the correction mode can be switched by remote control by the software switch after the installation.

In addition, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments and modifications may be appropriately combined.

1 ... CO ₂ sensor system 3 ... Sensor master unit 4 ... Management device 10 ... Sensor slave unit 11 ... Power supply unit 12 ... Wireless communication unit 13 ... Switch unit 14 ... Slave unit control unit 20, 20A ... CO ₂ sensor 22 ... Sensor control Unit 23 ... Non-volatile memory 24 ... CO ₂ measurement unit 25 ... Mode switching unit

Claims (6)

A CO ₂ sensor system with a CO ₂ sensor and the sensor slave unit,
The sensor slave unit
Power supply and
A switch unit that switches whether or not to supply power from the power supply unit to the CO _{2 sensor,}
It has a slave unit control unit that transmits interval information to the _{CO 2 sensor.}
The CO ₂ sensor is
_{A CO 2} measuring unit that measures the CO _{2 concentration,}
A non-volatile memory that stores the elapsed time obtained by integrating the measurement results by the CO _{2 measuring unit and the interval information, and}
It has a sensor control unit that transmits the measurement result to the sensor slave unit.
The switch unit, after starting the supply of power to the CO ₂ sensor, configured such that the sensor control unit to cut off power supply to the CO ₂ sensor and transmits the CO ₂ concentration in the sensor slave unit Being done
The sensor control unit is configured to execute correction of the _{CO 2} measurement unit when the elapsed time stored in the non-volatile memory becomes equal to or greater than a set value of a predetermined correction execution interval. ₂ sensor system. A sensor master unit that performs wireless communication with the sensor slave unit,
_{The CO 2} sensor system according to claim 1, further comprising a management device connected to the sensor master unit via a network. _{The CO 2} sensor system according to claim 2, wherein the management device is configured to transmit correction mode information regarding a correction mode to the CO _{2 sensor via the sensor master unit and the sensor slave unit.} The CO ₂ sensor has a mode switching unit capable of switching the correction mode, and has a mode switching unit.
_{The CO 2} sensor system according to claim 1 or 2, wherein the mode switching unit is a physical switch. The sensor control unit is configured to perform correction of the _{CO 2 measurement unit based on the correction mode.
The CO 2} sensor system according to claim 3 or 4, wherein the correction mode includes the set value and whether or not the sensor slave unit is permitted to execute wireless communication. The sensor control unit is configured to perform correction of the _{CO 2 measurement unit based on the correction mode.
The CO 2} sensor system according to any one of claims 3 to 5, wherein the correction mode _{includes a reference value used for correcting the CO 2} concentration measured by the _{CO 2 measuring unit.}

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