JPH06348976A - Fire sensor - Google Patents

Abstract

PURPOSE:To surely discriminate and detect abnormality of detector such as its degradation or disconnection when the abnormality is generated at a detector in the case when testing the operation of the fire sensor by connecting a resistor for test by inhibiting the input of a test signal from the outside to a testing means when an abnormality detecting means discriminates the abnormality at the detector. CONSTITUTION:When a resistance value of a thermistor 11 is increased or the thermistor 11 is disconnected by degradation during fire monitor, the detecting output of a fire detection circuit 10 is reduced lower than an abnormality discrimination level depending on resistors 52 and 53, and the output of a comparator 51 for abnormality discrimination turns to an L output. Corresponding to this L output, an AND circuit 61 is turned to an operation inhibiting state. In such a state, even when a switch 100 for test for testing the operation of a fire sensor 1 is turned on and the test signal is applied to the fire sensor 1, the AND circuit 61 does not generate H output. Therefore, an analog switch 42 is not turned on and a fire discrimination circuit 20 does not generate the H output. Thus, it can be discriminated that abnormality is generated at the fire sensor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire detector, and more particularly to a fire detector having a test function for a fire detector having a detection element whose resistance changes due to a fire phenomenon.

[0002]

2. Description of the Related Art As a fire detector for detecting a fire by utilizing a change in resistance value due to a fire phenomenon, a thermal type equipped with a temperature sensitive resistance element such as a thermistor whose resistance value is changed by heat generated by the fire. There are known fire detectors and gas-type fire detectors having a gas detection element whose resistance value changes depending on the gas generated by the fire.

When testing whether such a fire detector operates or not, a heating tester or a gas tester is used to actually test the fire detector installed on the ceiling surface or the like. It was tested by applying heat and gas and determining if the fire detector worked.

By the way, in the above-mentioned test method, since a dedicated heating tester or a heating gas tester is used, handling of these is complicated, and it takes a long time to test each sensor. Also, if the detector is installed at a high place, you may have to scaffold during the test, it is locked, or the fire is installed in a room that is inaccessible during use. In the case of sensors, there is the problem that tests cannot be performed.

For this reason, a test resistor is provided in the fire detector, and the test resistor is connected to a detection unit having a temperature sensitive resistance element, a gas detection element, or the like during an operation test, so that the detection unit can be protected from a fire. A method in which a test means for causing a similar pseudo resistance change is provided, and this test means is operated from the outside of a fire receiver or the like to perform an operation test to determine whether or not the fire detector operates. Is proposed.

In this method, the test means built in the fire detector is provided by giving a test command (test signal) to the fire detector from outside the fire receiver or the fire detector such as a test switch during the test. It works and tests, so heat,
Alternatively, it is not necessary to use a dedicated tester that uses gas, etc., and the test can be performed quickly even if there are many fire detectors, and even if it is installed at a high place or the room is locked, it is easy. There is an advantage that a test can be performed.

[0007]

Although the above method has the above advantages, the resistance value of the test resistance connected to the detection portion varies during the test, and therefore, the temperature sensitive resistance element and the gas are not detected. Even if the detection element such as the detection element is deteriorated or disconnected, the fire resistance may cause the fire detector to operate due to the connection of the test resistor.As a result, regardless of whether the fire detector is in a failure or abnormal state, However, there is a problem that it is judged as normal and the abnormality of the fire detector cannot be detected during the test.

In view of the above points, the present invention detects when a fire resistance is operated by connecting a test resistor to a detection unit having a detection element such as a temperature sensitive resistance element or a gas detection element. When deterioration or disconnection abnormality occurs in the element, the purpose is to be able to reliably determine and detect the abnormality.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a fire detecting portion having a detecting element whose resistance value changes due to a fire phenomenon,
A fire detector comprising: a fire discriminating means for discriminating whether or not the detection output of the fire detecting section has reached one or a plurality of different fire discriminating levels; Test means for adding to the fire detection section; an abnormality detection means for determining whether or not the detection output of the detection element is an abnormality determination value or more; and the abnormality detection means for producing a detection output of a predetermined value or more. And a test signal input inhibiting means for inhibiting the test signal from being input to the testing means when the determination is made.

Further, a fire detection section having a detection element whose resistance value changes due to a fire phenomenon, and fire discrimination means for discriminating whether or not the detection output of the fire detection section has reached one or more different fire discrimination levels. A fire detector including: a test unit that operates by an external test signal to add a test resistor to the fire detection unit; and whether the detection output of the detection element is equal to or greater than an abnormality determination value. An abnormality detection means for determining whether or not; when the abnormality detection means determines a detection output of a predetermined value or more, the fire determination means for performing a fire determination based on the output of the fire detection portion outputs a determination result. It is characterized in that a discrimination output prohibiting means for prohibiting and; are provided.

[0011]

As described above, the fire detector has a test means which operates according to a test signal from the outside, an abnormality detecting means which determines whether or not there is an abnormality in the detecting element, and the abnormality detecting means which detects an abnormality in the detecting element. At this time, since the test signal input prohibiting means for prohibiting the input of the test signal from the outside to the test means is provided, the test signal input prohibiting means operates when an abnormality occurs due to deterioration or disconnection of the detection element. To do. As a result, when a test signal is input to the fire detector from the outside,
Since this test signal is prohibited from being input to the test means,
The test means does not operate, and the fire detector does not output the test result indicating the normality of the detector due to the abnormality of the detection element.

Further, the fire detector has a test means which operates by a test signal from the outside, an abnormality detecting means for determining whether or not there is an abnormality in the detecting element, and an abnormality detecting means for detecting an abnormality in the detecting element. Since there is provided a discrimination output prohibiting means for prohibiting the fire discrimination means for discriminating a fire based on the output of the fire detecting portion from outputting the discrimination result, the discrimination can be made when an abnormality occurs due to deterioration or disconnection of the detection element. The output prohibition means operates. As a result, even if a test signal is input to the fire detector from the outside and the test means operates, the discrimination output prohibition means operates and the output of the detection element is input to the fire discrimination means, or The fire detector must output the test result indicating the normality of the detector due to the abnormality of the detection element, because it prohibits the means to output the discrimination output or the fire discrimination means to discriminate the detection output. There is no.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a fire detector according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment, where 1 is a thermistor 11 as a detection element whose resistance value changes due to a fire phenomenon.
Is a thermal fire detector using 9 and 9 is a fire receiver,
The sensor 1 is connected to the receiver 9 via a regional line consisting of a pair of power source and signal line. In addition, the fire detector 1
A test switch 100 that supplies a test signal to the sensor 1 during an operation test is connected.

The receiver 9 is connected with a large number of fire detectors 1 respectively provided in a plurality of fire warning areas via each area line. A single fire detector 1 is shown as a representative.

In the fire detector 1, 10 is a fire detection circuit consisting of a thermistor 11 and a resistor 12 connected in series to the thermistor 11, and 20 is a comparison for fire discrimination input by the detection output of the fire detection circuit 10. A fire discriminating circuit having a device 21 and first reference resistors 22 and 23 for giving a fire discriminating level to the comparator 21, is a transistor for transmitting a fire signal to which the fire discriminating output of the fire discriminating circuit 20 is input, The fire signal transmission circuit includes a switching element 31 such as a silicon control rectifying element, an operation indicator lamp 32 that is turned on by a fire signal, and a current limiting resistor 33.

Reference numeral 40 denotes the thermistor 1 of the fire detection circuit 10.
1 is a test circuit that is provided in parallel with 1 and has a test resistor 41 and an analog switch 42 that is serially connected to the test resistor 41 and that includes an analog switch 42, for example. An abnormality detection circuit having a comparator 51 for determining abnormality of the element and second reference resistors 52 and 53 for giving a reference value for abnormality determination to the comparator 51, 60 is an abnormality detection output of the abnormality detection circuit 50. Due to
AND that prohibits the test signal from inputting to the test circuit 40
This is a signal input prohibition circuit having a circuit 61.

Reference numeral 2 is a depolarizing circuit composed of a diode bridge circuit, 3 is a constant voltage circuit for supplying a constant voltage to various circuits in the sensor 1, 4 is a terminal to which the test switch 100 is connected, Reference numeral 5 is a resistor connected in series with the test switch 100.

In the fire receiver 9, 91 is a district relay for receiving a fire signal, 92 is a make contact for self-holding of the district relay 91, 93 is a resistance, 94 is a fire district indicator lamp, and 95 is The fire recovery switch 96 is a power source that supplies power to the receiver 9 and the fire detector 1.

Next, the operation of the first embodiment will be described.

When the thermistor 11 is normal and is not deteriorated or disconnected, the detection output of the fire detection circuit 10 is lower than the fire discrimination level by the resistors 22 and 23, and the resistance 52,
Since it is higher than the abnormality determination level by 53, the fire determination comparator 21 outputs an L (low) output to the abnormality determination comparator 5.
1 produces an H (high) output.

Due to the L output of the comparator 21, the switching element 31 is off and the fire signal transmission circuit 30 does not output a fire signal. Therefore, the district relay 91 of the fire receiver 9 does not operate, and the fire district indicator lamp 94 does not light.
Further, although the AND circuit 61 is in the operable state by the H output of the comparator 51, the test signal is not input because the test switch 100 is in the OFF state, and the AND circuit 61 is in the L output state. Therefore, the analog switch 42 of the test circuit 40 is in the off state, and the test resistor 41 is not added to the thermistor 11 of the fire detection circuit 10.

When a fire occurs, the resistance value of the thermistor 11 decreases and the detection output increases. When this detection output reaches the fire discrimination level by the resistors 22 and 23, the comparator 2
1 produces an H output, the switching element 31 turns on, outputs a fire signal to the receiver 9, and the operation indicator lamp 32
Lights up. Then, in response to the fire signal, the district relay 91 of the receiver 9 is turned on, the make contact 92 is closed, the fire district indicator lamp 94 is turned on, and a fire bell or a district bell (not shown) rings. In addition, fire detector 1 that worked
The receiver 9 recovers to the fire monitoring state by temporarily turning off the fire recovery switch 95.

By the way, the thermistor 11 of the fire detector 1
In the normal state, when the test switch 100 is pressed and turned on for the operation test, the test signal is input to the AND circuit 61 which is in the operable state by the H output of the comparator 51. As a result, the AND circuit 61 produces an H output. This H output turns on the analog switch 42 of the test circuit 40, and the test resistor 41 as a pseudo fire is added to the thermistor 11.

As a result, the detection output of the fire detection circuit 10 becomes equal to or higher than the fire discrimination level by the resistors 22 and 23, the comparator 21 produces an H output, the switching element 31 is turned on, and a fire signal is sent to the receiver 9. . By this fire signal, the district relay 91 is activated, the fire district indicator lamp 94 is turned on, and it is indicated that the fire detector has operated normally by the operation test.

On the other hand, if the resistance value rises or the wire breaks due to deterioration of the thermistor 11 during fire monitoring, the detection output of the fire detection circuit 10 drops below the abnormality determination level by the resistors 52 and 53. Due to this decrease in the detection output, the output of the abnormality determining comparator 51 becomes the L output. This L output puts the AND circuit 61 in the operation prohibited state.

In such a state, even if the test switch 100 is turned on and a test signal is given to the fire detector 1 for an operation test of the detector 1, the AND circuit 61 does not produce an H output. Therefore, the analog switch 42 does not turn on, and the fire determination circuit 20 does not generate H output. Therefore, the fire signal indicating the normal state of the detector is not input to the receiver 9 regardless of the operation of the test switch 100, and it is possible to determine that the fire detector 1 has an abnormality.

FIG. 2 shows a second embodiment of the fire detector according to the present invention.
It is an example of.

The embodiment of FIG. 2 differs from the embodiment of FIG. 1 only in the configuration and the position of the signal input prohibiting circuit 60 for prohibiting the input of the test signal input from the test switch 100. is there. And fire detector 1
The circuit configuration of the fire detection circuit 10, the fire determination circuit 20, the fire signal transmission circuit 30, the test circuit 40, the abnormality detection circuit 50, the nonpolar circuit 2 and the constant voltage circuit 3, and the fire receiver 9 of FIG. Is the same as.

The signal input prohibiting circuit 60 is the abnormality detecting circuit 5
It has an analog switch 62 which is turned on by the H output of the comparator 51 of 0 and turned off by the L output, and which is constituted by, for example, a transistor. This signal input inhibition circuit 60
It is provided between the constant voltage circuit 2 and the terminal 4 to which the test switch 100 is connected.

In the fire detector 1, when the thermistor 11 is in a normal state, the comparator 51 of the abnormality detection circuit 50 produces an H output as in the embodiment of FIG. The analog switch 62 of 60 is turned on. As a result, the test switch 1 is used for the operation test of the sensor.
When 00 is turned on, a test signal is input to the test circuit 40, the analog switch 42 is turned on, the test resistor 41 is added to the fire detection circuit 10, and an operation test is performed.

By the way, when the detection output of the fire detection circuit 10 falls below the abnormality determination level due to deterioration or disconnection of the thermistor 11, the comparator 51 becomes L output and the analog switch 62 of the signal input prohibition circuit 60 is turned off. It
As a result, the constant voltage circuit 3 does not supply the test switch 100 with power as a test signal.

Therefore, for the operation test, no test signal is generated even if the test switch 100 is turned on, and the test circuit 40
Since the test resistor 41 is not added to the fire detection circuit 10 because it does not operate, the fire discrimination comparator 21 does not generate an H output and does not send a fire signal indicating that the fire detector 1 operates normally.

In each of the first and second embodiments, the fire detection circuit 10 is the fire detection means, the fire discrimination circuit 20 is the fire discrimination means, the test circuit 40 is the testing means, and the abnormality detection circuit 50 is abnormal. The signal input prohibition circuit 60 of the detection means is an example of each of the test signal input prohibition means.

FIGS. 3 and 4 are third and fourth embodiments of the fire detector according to the present invention. In the third and fourth embodiments, when an abnormality occurs in the thermistor 11, the first and second embodiments prohibit the test signal from the test switch 100 from being input to the test circuit 40. However, the output of the fire signal is prohibited.

In the third embodiment of FIG. 3, the first and second
The difference from the embodiment is that an output cutoff circuit 70 having an AND circuit 71 is provided between the fire discrimination circuit 20 and the fire signal transmission circuit 30 to input the output of the fire discrimination circuit 20 and the output of the abnormality detection circuit 50. , An inverter 54 for inverting the output of the comparator 51 to the abnormality detection circuit 50, a latch circuit 55 composed of, for example, a flip-flop, and an output cutoff circuit 70 for inverting the output of the latch circuit 55. The point is that an inverter 56 for outputting is additionally provided. The fire detection circuit 10, the fire determination circuit 20, the fire signal transmission circuit 30, the test circuit 40, the depolarization circuit 2, the constant voltage circuit 3, and the fire receiver 9 are configured as shown in the embodiment of FIGS. Is the same as.

In the fire detector 1 thus constructed, when the thermistor 11 is in a normal state, the comparator 51 of the abnormality detection circuit 50 outputs H, the inverter 54 and the latch circuit 55.
Is an L output, and the inverter 56 is an H output. The H output of the abnormality detection circuit 50 makes the AND circuit 71 of the output cutoff circuit 70 operable.

When the resistance value of the thermistor 11 decreases due to a fire and the detection output of the fire detection circuit 10 rises, the comparator 21 produces an H output and the AND circuit 71 produces an H output.
The switching element 31 turns on and sends a fire signal to the receiver 9.

When the test switch 100 is turned on for the operation test, the test signal is input to the test circuit 40, the analog switch 42 is turned on, the test resistor 41 is added to the fire detection circuit 10, and the detection output rises. And the comparator 21
Produces output. As a result, the AND circuit 71 produces an H output, the switching element 31 is turned on, and the fire detector 1
Sends a fire signal to the receiver 9 indicating that the fire alarm operates normally.

When the thermistor 11 is deteriorated and its resistance value becomes high or the wire is broken, the detection output is lowered below the abnormality determination level by the resistors 52 and 53. As a result, the comparator 51 becomes L output, and the inverter 54
Changes to the H output, the latch circuit 55 is latched and becomes the H output, and the output of the inverter 56 is inverted to the L output indicating the abnormality detection output. Due to this abnormality detection output, the AND circuit 71 of the output cutoff circuit 70 is maintained in the operation prohibited state.

In such a state, when the test switch 100 is turned on for the operation test of the detector, the test signal is given to the fire detector 1 and the analog switch 42.
Is turned on, a test resistor is added to the fire detection circuit 10. As a result, the output of the fire detection circuit 10 rises above the fire discrimination level as in the case of a fire.
Produces an H output. However, since the operation of the AND circuit 71 is prohibited by the abnormality detection output of the abnormality detection circuit 50, the AND circuit 71 maintains the L output state. Therefore, the fire signal is not sent from the fire detector 1 to the receiver 9 regardless of the operation test, so that it is possible to determine that the fire detector 1 is abnormal.

The fourth embodiment of FIG. 4 differs from the third embodiment in that instead of the output cutoff circuit 70, an abnormality detection circuit 50 is provided between the fire detection circuit 10 and the fire discrimination circuit 20. The point is that an input cutoff circuit 80 having an analog switch 81, which is constituted by, for example, a transistor that is on / off controlled by an output, is provided. The configuration of the fire detection circuit 10, the fire discrimination circuit 20, the fire signal transmission circuit 30, the test circuit 40, the depolarization circuit 2, the constant voltage circuit 3, and the fire receiver 9 is as shown in FIGS. The embodiment 5 is similar to that of the first embodiment, and the abnormality determination circuit 50 is similar to the embodiment of FIG.

If the thermistor 11 is normal, the fire detector 1 having the above-described configuration has the abnormality detection circuit 50 producing an H output, and the analog switch 81 of the input cutoff circuit 80 is in the ON state, which causes a fire. The detection output of the detection circuit 10 is input to the comparator 21. Therefore, when the detection output rises due to the occurrence of a fire, the comparator 21 produces an H output, and the switching element 31 is turned on to send a fire signal, as in the above-described embodiments.

When the thermistor 11 is deteriorated or disconnected and the detection output is lowered, the abnormality detection circuit 50 outputs L as in the third embodiment. As a result, the analog switch 81 is turned off, and the detection output of the fire detection circuit 10 is prohibited from being input to the comparator 21.

In this state, when the test switch 100 is turned on for the operation test, a test signal is input to the test circuit 40, the analog switch 42 is turned on, and the test resistor 4 is turned on.
1 is added to the fire detection circuit 10. As a result, the detection output of the fire detection circuit 10 rises above the fire determination level, but is not input to the comparator 21 because the analog switch 81 is off. Therefore, the comparator 21 does not generate an H output that is a fire determination output, and the switching element 31 does not turn on, so that the fire signal indicating that the fire detector 1 is normal is not output to the receiver 9.

By the way, in the third and fourth embodiments,
Although the output of the fire determination circuit 20 is shut off or the input of the detection output to the fire determination circuit 20 is shut off when the thermistor 11 is abnormal, the determination operation of the fire determination circuit 20 may be prohibited. .

In this case, for example, in the embodiment shown in FIG. 4, the input cutoff circuit 80 is removed, and the fire discrimination circuit 20 is connected in parallel with the resistor 22 in series with a discrimination operation inhibiting resistor and an analog switch. It is provided by connecting a circuit. Then, when the abnormality detection circuit 50 does not detect the abnormality of the thermistor 11, the analog switch is turned off. When the abnormality is detected, the analog switch is turned on and the prohibiting resistor is connected in parallel with the resistor 22. As a result, the fire determination level given to the comparator 21 is higher than the normal level even if the test resistor 41 is added to the fire detection circuit 10 in which the thermistor 11 is disconnected.
Raised to a level that produces no output. Therefore, in the state where the thermistor 11 is disconnected, even if the test resistance 41 is added by the test signal during the operation test and the detection output exceeds the normal fire discrimination level, the comparator 2
1 does not work.

In each of the third and subsequent embodiments, the fire detection circuit 10 is the fire detection means, the fire determination circuit 20 is the fire determination means, the test circuit 40 is the testing means, and the abnormality detection circuit 50 is abnormal. The output cutoff circuit 70 of the detection means,
The input cutoff circuit 80 and the series circuit formed by the resistance 22 of the fire discrimination circuit 20 in parallel with the resistance for discrimination operation and the analog switch are examples of the discrimination output prohibition means. Further, the input prohibition circuit 80 is an input prohibition means,
An example of each of the discrimination prohibition means is a series circuit of the output interruption circuit 70, which is a parallel circuit of the output cutoff means and is provided with a resistance for discrimination operation and an analog switch.

By the way, in each of the above-mentioned embodiments, the description has been given of the case of the fire detector using the thermistor which is the temperature sensitive resistance element as the detection element whose resistance value changes due to the fire phenomenon. A sintered body containing stannic oxide as a main material was provided between the electrodes, for example, a gas detection element whose resistance value was changed by carbon monoxide, or a thin film of stannic oxide or the like was formed between a pair of electrodes. The same applies to the case of a fire detector using an odor detecting element whose resistance value changes depending on the burning odor.

When a gas detection element is used as the detection element, a gas detection element is provided in place of the thermistor 11 in FIGS. 1 to 4, eg, FIG. 1, and a heater for the gas detection element is provided with a power source, for example, intermittently. A heating circuit for supplying electricity may be provided. When an odor detecting element is used as the detecting element, the odor detecting element may be provided instead of the thermistor 11 in FIG. 1 as in the case of the gas detecting element.

Further, in each of the above embodiments, the fire detector 1
Of the fire detector may be provided outside the device, for example, near the test switch 100, and an abnormality indicating that the abnormality detection circuit 50 has detected an abnormality of the fire detection circuit 10 is provided. The indicator light may be provided inside or outside the fire detector 1.

When the operation indicator lamp is provided outside the fire detector, for example, the operation indicator lamp may be connected in parallel with the operation indicator lamp 32 provided on the detector 1. By doing so, even when the test switch 100 is provided in a place where the sensor cannot be seen directly, the operation indicator lamp beside it can easily determine whether or not the fire sensor has been operated by the operation test. Can be determined.

When the abnormality indicator lamp is provided, it is provided inside or outside the sensor so that the abnormality indicator lamp is turned on when the comparator 51 of the abnormality detection circuit 50 produces an L output indicating an abnormality. Good. With this configuration, when an abnormality occurs in the detection element, the abnormality indicator lamp is immediately turned on, so that the abnormality can be known before performing the operation test.

[0054]

According to the present invention, the fire detector has a test means which operates by a test signal from the outside, an abnormality detecting means for determining whether or not there is an abnormality in the detecting element, and the abnormality detecting means detects an abnormality in the detecting element. When the judgment is made, the test signal input prohibiting means for prohibiting the input of the test signal from the outside to the testing means is provided, so that the test signal input prohibiting means is provided when the detection element is abnormal due to deterioration or disconnection. Works. As a result, when a test signal is input to the fire detector from the outside, this test signal is prohibited from inputting to the test means, so that the test means does not operate and the fire detector detects the abnormality due to the detection element. It does not output the test result indicating the normality of the container.

Further, the fire detector has a testing means which operates by a test signal from the outside, an abnormality detecting means which determines whether or not there is an abnormality in the detecting element, and when the abnormality detecting means determines an abnormality in the detecting element. Since there is provided a discrimination output prohibiting means for prohibiting the fire discrimination means for discriminating a fire based on the output of the fire detecting portion from outputting the discrimination result, the discrimination can be made when an abnormality occurs due to deterioration or disconnection of the detection element. The output prohibition means operates. As a result, even if a test signal is input to the fire detector from the outside and the test means operates, the discrimination output prohibition means operates and the output of the detection element is input to the fire discrimination means, or The fire detector must output the test result indicating the normality of the detector due to the abnormality of the detection element, because it prohibits the means to output the discrimination output or the fire discrimination means to discriminate the detection output. There is no.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a first embodiment of a fire detector according to the present invention.

FIG. 2 is a circuit diagram of a second embodiment.

FIG. 3 is a circuit diagram of a third embodiment.

FIG. 4 is a circuit diagram of a fourth embodiment.

[Explanation of symbols]

 1 Fire Detector 10 Fire Detection Circuit 11 Thermistor (Detection Element) 20 Fire Discrimination Circuit 40 Test Circuit 41 Test Resistance 50 Abnormality Detection Circuit 60 Signal Input Prohibition Circuit 70 Output Cutoff Circuit 80 Input Cutoff Circuit 9 Fire Receiver 100 Test Switch

Claims (5)

[Claims] 1. A fire detection unit having a detection element whose resistance value changes due to a fire phenomenon, and the detection output of the fire detection unit is 1.
Or, a fire detector equipped with fire discrimination means for discriminating whether or not a plurality of different fire discrimination levels are reached, a test in which a test resistance is added to the fire detection section by operating with a test signal from the outside. An abnormality detecting means for determining whether or not the detection output of the detecting element is an abnormality determination value or more; and the test signal when the abnormality detecting means determines a detection output of the abnormality determination value or more. A fire detector comprising: a test signal input prohibiting means for prohibiting the input from the test means. 2. A fire detection section having a detection element whose resistance value changes due to a fire phenomenon, and the detection output of the fire detection section is 1
Or, a fire detector equipped with fire discrimination means for discriminating whether or not a plurality of different fire discrimination levels are reached, a test in which a test resistance is added to the fire detection section by operating with a test signal from the outside. Means for detecting the fire when the detection output of the detection element determines whether or not the detection output is equal to or greater than an abnormality determination value; and the abnormality detection means determines the detection output equal to or greater than the abnormality determination value. A fire detector comprising: a discrimination output prohibiting unit that prohibits a fire discrimination unit that discriminates a fire based on the output of the unit from outputting the discrimination result. 3. The input for prohibiting discrimination output prohibits the output of the fire detection unit from being input to the fire discrimination means when the abnormality detection means discriminates a detection output equal to or more than an abnormality discrimination value. The fire detector according to claim 2, which is a prohibition means. 4. The discriminating output prohibiting means is an output intercepting means for intercepting the discriminating output of the fire discriminating means when the abnormality detecting means discriminates a detection output equal to or more than an abnormality discriminating value. The fire detector according to claim 2. 5. The discriminating output prohibiting means is discriminating prohibiting means for prohibiting the discriminating operation of the fire discriminating means when the abnormality detecting means discriminates a detection output equal to or more than an abnormality discriminating value. And a fire detector.