RU2409865C1 - Method of early fire detection and device for its realisation - Google Patents

Abstract

FIELD: fire safety. ^ SUBSTANCE: device that realises proposed method comprises sensors to measure gas components, amplifiers, analogue-digital converters, microprocessor, alarm signal generator, light alarm, sound alarm, modulating code generator, setting oscillator, phase manipulator, power amplifier, transmitting antenna, receiving antenna, high frequency amplifier, heterodyne, mixers, intermediate frequency amplifiers, phase splitter into two, narrow band filters, phase doubler, phase changers by 90, phase detector, registration unit, summator, multiplier, amplitude detector and key. ^ EFFECT: improved noise immunity of device and accuracy of fire safety object ID and coordinates detection by suppression of false signals received along mirror and combination channels. ^ 2 cl, 6 dwg

Description

The proposed method and device relates to the field of fire safety and can be used to detect fire in the early stages of smoldering and ignition of combustible materials. Known methods and devices for early fire detection (RF patents Nos. 2,207.631, 2.110.094, 2.078.377, 2.177.179, 2.256.228, 2.256.231, 2.340.002; US patents Nos. 5,049.861, 5.079. 422; patent EP No. 0.940.679; patent WO No. 0.948.070; Sharovar F. I. Fire alarm devices and systems. - M .: Stroyizdat, 1985, pp. 292-295 and others).

Of the known methods and devices closest to the proposed are the "Method for early fire detection and device for its implementation" (RF patent No. 2.340.002, G08B 17/117, 2007), which are selected as prototypes.

Known technical solutions provide the expansion of the monitoring zone of fire safety facilities and the timely transmission of alarms from fire safety facilities to the fire department and / or to the control room by using a radio channel and complex signals with phase shift keying. Moreover, the device for receiving signals with phase shift keying, located in the fire department and / or at the control room, is built according to a superheterodyne circuit in which the same value of the intermediate frequency ω _pr can be obtained by receiving signals at two frequencies ω _s and ω _s , i.e.

ω _ol = ω _s -ω _g and ω _ol = ω _g -ω _s .

Therefore, if the tuning frequency ω _to take over the main receiving channel, along with it will be a mirror receiving channel frequency ω _of which differs from the frequency _with ω and 2ω _straight symmetrically located (mirror) relative to frequency ω LO _g.

The conversion on the mirror channel of the reception occurs with the same conversion coefficient K _ol as on the main channel (Fig.6). Therefore, it most significantly affects the inventiveness and noise immunity of the device.

In addition to the mirror, there are other additional (combinational) reception channels. In general terms, any combination receive channel takes place when the following conditions are met:

ω _CR = | ± m · ω _ki ± n · ω _g |,

where ω _ki is the frequency of the i-th Raman reception channel;

m, n, i are positive integers.

The most harmful combinational reception channels are those generated by the interaction of the first harmonic of the signal frequency with the harmonics of the frequency of the local oscillator of the small order (second, third, etc.), since the sensitivity of the device through these channels is close to the sensitivity of the main channel. So, two combination channels with m = 1 and n = 2 correspond to frequencies:

ω _k1 = 2ω _g -ω _pr and ω _k2 = 2ω _g + ω _pr

where 2ω _g is the second harmonic of the local oscillator frequency.

The presence of false signals (interference) received via the mirror and Raman channels leads to a decrease in the noise immunity of the device and the accuracy of determining the identification number of the fire safety object and its coordinates.

An object of the invention is to increase the noise immunity of the device and the accuracy of determining the identification number of the fire safety object and its coordinates by suppressing false signals (interference) received via mirror and combination channels.

The problem is solved in that the method of early fire detection, based in accordance with the closest analogue on the fact that they measure the current concentration in the air of gas components selected from the groups consisting of hydrogen, carbon monoxide and aromatic hydrocarbons released during smoldering of combustible materials, determine the ratio of the measured concentrations of the gas components, which is compared with its predetermined value, while an alarm is generated when the specified values of the concentration ratios coincide gas components, generate, along with an alarm, a high-frequency oscillation and a modulating code that displays the identification number of the fire safety object and its coordinates, manipulate the high-frequency oscillation in phase with a modulating code, amplify the generated complex signal with phase manipulation in power, radiate it into the air, pick it up the control room of the observation and / or in the fire service, is converted by frequency, divided by phase into two, emit harmonic oscillation at a frequency ω _pr / 2, double it f ABC, isolate harmonic oscillation at an intermediate frequency ω _pr , phase shift it by 90 ° and use it as a reference voltage for synchronously detecting a received signal with phase shift keying at an intermediate frequency, isolate and record a low-frequency voltage proportional to the modulating code, differs from the closest analogue the fact that they isolate the first voltage of the intermediate frequency, phase shifted by 90 ° the local oscillator voltage, use it to convert the frequency of the received signal, output they add a second intermediate frequency voltage, sum it with the first intermediate frequency voltage, multiply the total intermediate frequency voltage with the received signal, isolate the harmonic voltage at the frequency ω _{g of the} local oscillator, detect it and use it to resolve further processing of the total intermediate frequency voltage.

The problem is solved in that a device for early fire detection, containing, in accordance with the closest analogue at the fire safety facility, n sensors for concentration of gas components in the air released during smoldering of combustible materials, each sensor being connected via a matching amplifier and an analog-to-digital converter connected to a microprocessor connected to an alarm shaper and designed to compare current values measured by sensors radios gas components with the simultaneous formation of a concentration ratio of the current values and comparing the formed ratio with given values. A master oscillator, a phase manipulator, the second input of which is connected via a modulator code generator to a second microprocessor output, a power amplifier and a transmitting antenna are connected in series to the second output of the microprocessor, and a high-power amplifier is connected in series to the output of the receiving antenna at the control room and / or in the fire department frequency, the first mixer, the second input of which is connected to the first output of the local oscillator, and the first intermediate frequency amplifier, to the output of the phase divider by two p consequently, a first narrow-band filter, a phase doubler, a second narrow-band filter, a first 90 ° phase shifter, a phase detector and a recording unit are connected, different from the closest analogue in that it is equipped with a second and third 90 ° phase shifters, a second mixer, a second intermediate frequency amplifier, an adder, a multiplier, a third narrow-band filter, an amplitude detector and a key, and the second phase shifter 90 °, the second mixer, the second input of which is connected to the second output of the local oscillator connected to the output of the high-frequency amplifier, a second intermediate-frequency amplifier, a third phase shifter 90 °, an adder, the second input of which is connected to the output of the first intermediate-frequency amplifier, a multiplier, the second input of which is connected to the output of the high-frequency amplifier, a third narrow-band filter, an amplitude detector and a key, the second input of which is connected to the output of the adder, and the output is connected to the input of the phase divider by two and to the second input of the phase detector.

Temporal dependences of the concentrations of the main gas components released during smoldering of cotton are shown in FIG. Temporal dependences of the concentrations of the main gas components released during smoldering of wood are depicted in FIG. 2. The block diagram of the device for early fire detection is shown in Figs. 3 and 4. Timing diagrams explaining the principle of operation of the device are shown in Fig. 5. A frequency diagram illustrating the formation of additional receive channels is shown in FIG. 6.

A device for early fire detection contains n channels, each of which is, for example, a gas sensor 1.i (i = 1, 2, ..., n), to which a matching amplifier 2.i and an analog-to-digital converter 3 are connected .i. The output of each analog-to-digital converter 3.i is connected to the corresponding input of the microprocessor 4 connected to the shaper 5 of light and sound alarms, equipped with a light 6 and sound 7 signaling devices, while the output 8 of the shaper 5 is connected to a central fire protection concentrator (not shown) . The number of channels depends on the number of gas components, the concentrations of which are measured simultaneously at the initial stage of ignition. A modulator code generator 9, a phase manipulator 11, the second input of which is connected to the output of the microprocessor 4 through a master oscillator 10, a power amplifier 12, and a transmitting antenna 13 are connected to the second output of the microprocessor 4.

A device for receiving complex signals with phase shift keying (QPSK) contains a receiving antenna 14 connected in series, a high-frequency amplifier 15, a first mixer 17, a second input of which is connected to the first output of the local oscillator 16, and a first intermediate frequency amplifier 18, connected in series to the second output of the local oscillator 16 the second phase shifter 26 by 90 °, the second mixer 27, the second input of which is connected to the output of the high-frequency amplifier 25, the second intermediate frequency amplifier 28, the third phase shifter 29 by 90 °, the adder 30, second the input of which is connected to the output of the first intermediate frequency amplifier 18, a multiplier 31, the second input of which is connected to the output of the high-frequency amplifier 15, the third narrow-band filter 32, the amplitude detector 33, the key 34, the second input of which is connected to the output of the adder 30, the phase divider 19 two, the first narrow-band filter 20, the phase doubler 21, the second narrow-band filter 22, the first phase shifter 23 by 90 °, a phase detector 24, the second input of which is connected to the output of the key 34, and the registration unit 25.

A device for receiving complex QPSK signals is installed at the control room and / or in the fire service.

The device for early fire detection can be implemented on well-known elements of domestic and foreign production, such as semiconductor sensors such as PGS-1 or Model 911 sensors from Sieges (Germany), MICS 1110 from Motorola (USA), microprocessors like P1C12C509-A Motorola firms, standard AD9202 ADCs from Analog Devices (1999 catalog) and indicators of different brands.

The proposed method is implemented as follows.

It has been established that the initial stages of smoldering and ignition of most known combustible materials are characterized by the evolution of gas components, the main ones being hydrogen (H ₂ ), carbon monoxide (CO), carbon dioxide (CO ₂ ) and aromatic hydrocarbons (C _x H _y ), and the concentrations of these gases vary over time.

The experimentally obtained time dependences of the concentrations of hydrogen, carbon monoxide and aromatic hydrocarbons in the air, in the first few minutes after the start of smoldering cotton and wood, are shown in FIGS. 1 and 2, respectively, where K is the current value of the concentration of the gas component in air in percent.

Analysis of the graphs shows that during the first minutes of smoldering, there is a sharp gas evolution simultaneously of several gases, namely hydrogen, aromatic hydrocarbons, carbon monoxide and carbon dioxide.

The values of the concentration of emitted gases for different combustible materials may be different, but the release of carbon monoxide is always accompanied by the release of hydrogen, aromatic hydrocarbons and carbon dioxide. In this case, the values of the ratios of the concentrations of the listed gases lie within certain limits.

It is established that in the first 2-3 minutes of the beginning of the smoldering process of the main combustible materials, the ratios of the concentrations in the air of aromatic hydrocarbons, hydrogen, carbon monoxide and carbon dioxide at each current time point are:

K _CxHy : Kn ₂ : K _CO : Kso ₂ = 1: 1.5-2.5: 6.0-8.5: 2.5-4.0

Moreover, the values of the ratio of concentrations, for example, hydrogen and carbon monoxide are in the range of 1: 2.4-5.6 at each current point in time.

The above ratios of the concentrations of the main gas components are selected as the specified ratios of quantities with which the ratio of the current concentrations of these components is compared, and if they coincide, an alarm is generated.

Each of the semiconductor gas sensors 1.1-1.n, sensitive to the effects of one of the listed gas components (H ₂ , CO, CO ₂ , and C _x H _y ), changes its conductivity when measuring the concentration of this component in air, resulting in the output of the corresponding sensor 1.1-1.n an electrical signal appears, the value of which corresponds to a certain concentration of this gas component in the air. Then this signal is amplified and converted using the appropriate Converter 3.1.-3.n into a digital signal.

The microprocessor 4 continuously or with a predetermined frequency, for example, after 0.1-1 minute polls the sensors 1.1-1.n, compares the current signal values (corresponding to the current values of the concentration of gas components in the air) received from them and the obtained ratios of the current signal values compares with predetermined ratios of signal values recorded earlier and stored in its memory. If the ratios of the current values of the signals coincide with the specified ratios of values, the shapers 5 and 9 receive signals that generate alarms on them: light, sound, as well as the signal supplied from output 8 to the central fire protection concentrator, and the modulating code M (t), showing the identification number of the fire safety facility, respectively.

The device generates a steady alarm in the second or third minutes after the start of artificially induced smoldering of construction debris, selected as combustible material. For example.

In the first minute of smoldering construction debris, consisting of rags with a predominant cotton content, the ratio was:

K _CxHy : Kn ₂ : K _CO : Kso ₂ = 1: 2.6: 6: 3.7,

in the third minute:

K _CxHy : Kn ₂ : K _CO : Kso ₂ = 1: 2.1: 5: 3.

Accordingly, the ratio of hydrogen and carbon monoxide in the first minute:

Kn ₂ : K _CO = 1: 2,3,

and in the third minute:

Kn ₂ : K _CO = 1: 2.4.

When smoldering construction waste with a predominant composition of wood (shavings, wood chips, veneer) in the first minute, the ratio:

K _CxHy : Kn ₂ : K _CO : Kso ₂ = 1: 1.6: 8.5: 3,

in the third minute:

K _CxHy : Kn ₂ : K _CO : Kso ₂ = 1: 2.1: 7: 2.8.

The ratio of Kn ₂ : K _CO = 1: 2.6 in the first minute and Kn ₂ : K _CO = 1: 5.3 in the third minute.

When the ratio of the current concentration values of the main gas components with the given ratios coincides, a signal is generated in the microprocessor 4, which from its second output is fed to the input of the master oscillator 10 and turns it on.

The master oscillator 10 generates a high-frequency oscillation (figure 5, a)

U _c (t) = V _c cos (ω _c t + φ _c ), 0≤t≤T _c ,

where V _c , ω _c , φ _c , T _c is the amplitude, carrier frequency, initial phase, and duration of the high-frequency oscillation, which is fed to the second input of the phase manipulator 11, the first input of which is supplied with the modulating code M (t) from the output of the shaper 9 ( 5, b) displaying the identification number of the security object.

At the output of the phase manipulator 11, a complex QPSK signal is generated (Fig. 5, c)

U ₁ (t) = V _c · cos [ω _c · t + φ _k (t) + φ _c ], 0≤t≤T _c ,

where φ _k (t) = {0, π} is the manipulating component of the phase, which displays the law of phase manipulation in accordance with the modulating code M (t) (Fig. 5, b), and φ _k (t) = const at k · τ _e <t <(k + 1) τ _e and can change abruptly at t = τ _e , i.e. at the borders between elementary premises (k = 1, 2, ... N);

τ _e , N is the duration and number of chips that make up a signal of duration T _s (N · τ _e = T _c ), which, after amplification in the power amplifier 12, enters the antenna 13, is transmitted to the air, is captured by the receiving antenna 14 and through the high-frequency amplifier 15 is fed to the first inputs of the mixers 17 and 27, the second inputs of which are fed to the local oscillator voltage 16:

U _g1 (t) = V _g cos (ω _g t + φ _g ),

U _g2 (t) = V _g · cos (ω _g · t + φ _g + 90 °).

At the outputs of the mixers 17 and 27, voltages of combination frequencies are generated. Amplifiers 18 and 28 are allocated voltage intermediate (differential) frequency (figure 5, g)

U _pr1 (t) = V _pr · cos [ω _pr · t + φ _k (t) + φ _pr ],

_Np2 U (t) = V _pr · cos [ω _{ave · t + φ k (t)} + φ _pr -90 °], 0≤t≤T _c,

where V _ave = _^1/2 · V _c V _r;

ω _CR = ω _with -ω _g - intermediate (difference) frequency;

φ _CR = φ _s -φ _g .

The voltage U _CR2 (t) from the output of the intermediate frequency amplifier 28 is supplied to the input of the phase shifter 29 by 90 °, at the output of which a voltage is generated

U _pr3 (t) = V _pr · cos [ω _pr · t + φ _k (t) + φ _pr -90 ° + 90 °] = V _pr · cos [ω _pr · t + φ _k (t) + φ _pr ], 0≤t≤T _c .

Voltages U _CR1 (t) and U _CR3 (t) are supplied to two inputs of the adder 30, at the output of which the total voltage is formed

U _Σ (t) = V _Σ · cos [ω _pr · t + φ _k (t) + φ _pr ], 0≤t≤T _c ,

where V _Σ = 2V _ave .

This voltage is supplied to the first input of the multiplier 31, to the second input of which a received signal U ₁ (t) is supplied from the output of the high-frequency amplifier 15. At the output of the multiplier, a harmonic voltage is formed

U ₂ (t) = V ₁ · cos (ω _g · t + φ _g ), 0≤t≤T _c ,

where: V ₁ = _^1/2 V _c · V _Σ;

which is allocated by the narrow-band filter 32, is detected by the amplitude detector 33 and is supplied to the control input of the key 34, opening it. In the initial state, the key 34 is always closed. The tuning frequency ω _{n of the} narrow _- band filter 32 is chosen equal to the frequency ω _{g of the} local oscillator 16 (ω _n = ω _g ).

In this case, the total voltage U _Σ (t) from the output of the adder 30 through the public key 34 is supplied to the first (information) input of the phase detector 24 and to the input of the phase divider 19 into two. The output of the latter is voltage

U ₃ (t) = V ₃ · sin (ω _pr / 2 · t + φ _pr / 2), 0≤t≤T _c ,

where V ₃ = 0.707V ₂ .

This voltage is allocated by a narrow-band filter 20 and is fed to the input of the phase doubler 21, at the output of which a harmonic voltage is generated

₄ U (t) = V ₄ · sin (ω _ave · t + φ _etc.), 0≤t≤T _c,

₄ where V = _^1/2 V ^{₂ March,}

which is allocated by the narrow-band filter 22 and enters the input of the phase shifter 23 by 90 °. At the output of the latter a harmonic voltage is generated (FIG. 5, e)

U ₅ (t) = V ₄ · sin (ω _pr · t + φ _pr + 90 °) = V ₄ · cos (ω _pr · t + φ _pr ), 0≤t≤T _c ,

which is used as the reference voltage and is supplied to the second (reference) input of the phase detector 24.

As a result of synchronous detection at the output of the phase detector 24, a low-frequency voltage is generated (figure 5, g)

U _n (t) = V _n cosφ _k (t), 0≤t≤T _c ,

V wherein _n = _^1/2 V _Σ · V _n,

proportional to the modulating code M (t) (Fig. 5, b), which is focused by the registration unit 25.

The operation of the device described above corresponds to the case of receiving useful QPSK signals along the main channel at a frequency ω _s (Fig. 6).

If a false signal (interference) is received on the mirror channel at a frequency of ω ₃

U _s (t) = V _s · cos (ω _s · t + φ _s ), 0≤t≤T _s ,

then the amplifiers 18 and 28 of the intermediate frequency are allocated the following voltages:

_WP4 U (t) = V _WP4 · cos (ω _ave · t + φ _WP4)

_Np5 U (t) = V _WP4 · cos (ω _ave · t + φ _WP4 + 90 °), 0≤t≤T _s,

where V _pr = _^1/2 V _s · V _r;

_straight ω = ω _r -ω _s - intermediate frequency;

φ _pr4 = φ _g -φ _s .

The voltage U _CR5 (t) from the output of the intermediate frequency amplifier 28 is supplied to the input of the phase shifter 29 by 90 °, at the output of which the following voltage is generated

_Pr6 U (t) = V _WP4 · cos (ω _ave · t + φ _np + 90 ° + 90 °) = - V _WP4 · cos (ω _ave · t + φ _etc.).

Voltages U _CR4 (t) and U _CR6 (1), supplied to the two inputs of the adder 30, are compensated at its output.

Therefore, a false signal (interference) received through the mirror channel at a frequency of ω _s is suppressed with the help of an “outer ring” consisting of a local oscillator 16, mixers 17 and 27, phase shifters 26 and 29 by 90 °, amplifiers 18 and 28 of intermediate frequency and an adder 30 and implements a phase compensation method.

For a similar reason, a false signal (interference) received on the first combination channel at a frequency ω _{k1 is also} suppressed.

If a false signal (interference) is received on the second combination channel at a frequency ω _k2

U _к2 (t) = V _к2 · cos (ω _к2 · t + φ _к2 ), 0≤t≤T _к2 ,

the amplifiers 18 and 28 distinguish the following voltages:

_Pr7 U (t) = V _pr7 · cos (ω _ave · t + φ _pr7)

_Pr8 U (t) = V _pr7 · cos (ω _ave · t + φ _pr7 -90 °), 0≤t≤T _k2

_pr7 where V = _^1/2 · V V _{k2 g;}

ω = ω _{ave k2} -2ω _g - intermediate frequency;

φ _pr7 = φ _k2 -φ _g .

The voltage from the output of the intermediate frequency amplifier 28 is supplied to the input of the phase shifter 29 by 90 °, at the output of which a voltage is generated

U _pr9 (t) = V _pr7 · cos (ω _pr · t + φ _pr7 -90 ° + 90 °) = V _pr7 · cos (ω _pr · t + φ _pr7 ).

Voltages U _CR7 (t) and U _CR9 (t) are supplied to two inputs of the adder 30, at the output of which a total voltage is generated

U _Σ1 (t) = V _Σ1 · cos (ω _pr · t + φ _pr7 ), 0≤t≤T _k2 ,

where V _Σ1 = 2V _pr7 ,

which is fed to the first input of the multiplier 31, to the second input of which a received false signal (interference) V _k2 (t) is supplied from the output of the high-frequency amplifier 15. The output of the multiplier 31 is formed voltage

U ₆ (t) = V ₆ · cos (2ω _g · t + φ _g ), 0≤t≤T _k2 ,

₆ where V = _^1/2 · V V _{Σ1 g;}

which does not fall into the passband of the narrow-band filter 32, the key 34 does not open and the false signal (interference) received on the second combination channel at a frequency ω _k2 is suppressed by the "inner ring" consisting of a multiplier 3, a narrow-band filter 32, an amplitude detector 33, key 34 and implements the method of narrow-band filtering.

The method and device provide the expansion of the monitoring zone of fire safety facilities and the timely transmission of an alarm signal from fire safety facilities to the fire department and / or to the control tower.

This is achieved using a radio channel and complex phase-shift signals.

These signals allow the use of structural selection. This means that it becomes possible to separate signals operating in the same frequency band and at the same time intervals.

The width of the spectrum Δf _{2 of the} second harmonic is determined by the duration T _{c of the} signal Δf ₂ = 1 / T _s , while the width of the spectrum Δf _{c of the} QPSK signal is determined by the duration τ _{e of} its elementary premises Δf _c = 1 / τ _e , i.e. the width of the spectrum of the second harmonic of the signal is N times smaller than the width of the spectrum Δf _{from the} input signal (Δf _c / Δf ₂ = N).

Consequently, as a result of dividing the phase by two and doubling the phase of the QPSK signal, its spectrum “folds” N times. This makes it possible to detect the QPSK signal even when its power at the receiver input is less than the power of interference and noise. In addition, due to narrow-band filtering, it is possible to filter a significant part of noise and interference, and thereby increase the sensitivity of the receiver.

In the well-known A. A. Pistolkors circuit, which also provides the selection of the reference voltage necessary for synchronous detection of the received signal directly from the signal itself, there is “reverse operation”. This is explained by the fact that in this circuit, due to the frequency doubler, the phase manipulation is completely erased, i.e. the signal is destroyed. Therefore, the generated reference voltage from the destroyed signal does not have strict coherence with the QPSK signal, which is why “reverse work” occurs, i.e. the low-frequency signal at the output of the phase detector is perceived as “negative”: zeros instead of ones and vice versa.

In the proposed receiver, the QPSK signal is fed to a phase divider, and not to a frequency doubler. Therefore, the QPSK signal is not destroyed, but its phase deviation only decreases, as a result of which an intermediate frequency oscillation appears, which is strictly in phase with the QPSK signal. The latter eliminates the “reverse operation” and increases the reliability of the allocation of low-frequency voltage proportional to the modulation code M (t).

Simultaneous monitoring of several gases increases the reliability of fire detection precisely in the early stages of smoldering and ignition. This eliminates the possibility of false alarms of the measuring device when increasing the concentration of one of the gases for any of the reasons that do not correspond to the ignition process. The latter is possible, for example, as a result of leakage of gases from cylinders, tanks or pipelines located inside or near the protected premises.

Thus, the proposed method and device in comparison with prototypes provide increased noise immunity and accuracy of determining the identification number of the fire safety object and its coordinates.

This is achieved by suppressing false signals (interference) received via mirror and Raman channels.

Claims (2)

1. The method of early fire detection, based on the fact that measure the current value of the concentration in the air of gas components selected from the group consisting of hydrogen, carbon monoxide, carbon dioxide and aromatic hydrocarbons released during smoldering of combustible materials, determine the ratio of the measured concentrations of gas components , which is compared with its predetermined value, while an alarm signal is formed when the specified values of the ratios of the concentration of gas components coincide, form along with the signal alarms, a high-frequency oscillation and a modulating code that displays the identification number of the fire safety object and its coordinates, manipulate the high-frequency oscillation in phase with the modulating code, amplify the generated complex signal with phase manipulation in power, radiate it on the air, pick it up at the control room and / or in the fire service, convert the frequency-divide phase two, isolated harmonic oscillation frequency ω _ave / 2, its dual phase isolated harmonic oscillation on the intermediate th frequency ω _ave / 2 shifted its phase by 90 ° and used as the reference voltage for the synchronous detection of the received signal with phase shift keying at the intermediate frequency, allocate and record the low-frequency voltage proportional to the modulating code, characterized in that the separated first voltage intermediate frequency, phase shifted by 90 ° the voltage of the local oscillator, use it to convert the frequency of the received signal, allocate a second voltage of an intermediate frequency, sum it with the first by voltage of the intermediate frequency, the total voltage of the intermediate frequency is multiplied with the received signal, the harmonic voltage at the frequency ω _{g of the} local oscillator is isolated, it is detected and used to allow further processing of the total voltage of the intermediate frequency. 2. A device for early fire detection, containing n sensors of concentrations in the air of gas components released during the smoldering of combustible materials, each sensor through a series-connected matching amplifier and an analog-to-digital converter connected to a microprocessor connected to an alarm conditioner and intended for comparison the current values of the concentrations of the gas components measured by the sensors with the simultaneous formation of the ratios of the current concentrations and cf Avoiding the generated relationship with its given value, a master oscillator, a phase manipulator, the second input of which is connected to the second microprocessor output by a modulator code generator, a power amplifier and a transmitting antenna, are connected to the second output of the microprocessor, and at the control room and / or in the fire service a high-frequency amplifier, a first mixer, the second input of which is connected to the first output of the local oscillator, and the first intermediate frequency amplifier, the first narrow-band filter, the phase doubler, the second narrow-band filter, the first phase shifter 90 °, the phase detector and the registration unit, characterized in that it is equipped with the second and third phase shifters 90 °, the second are connected in series to the output of the phase divider into two a mixer, a second intermediate-frequency amplifier, an adder, a multiplier, a third narrow-band filter, an amplitude detector and a key, and the second phase shifter 9 is connected in series to the second output of the local oscillator 0 °, a second mixer, the second input of which is connected to the output of the high-frequency amplifier, a second intermediate frequency amplifier, a third phase shifter 90 °, an adder, the second input of which is connected to the output of the first intermediate-frequency amplifier, a multiplier, the second input of which is connected to the output of the high-frequency amplifier frequency, a third narrow-band filter, an amplitude detector and a key, the second input of which is connected to the output of the adder, and the output is connected to the input of the phase divider by two and to the second input of the phase detector.

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