RU2531883C2 - Method of early detection of fire and device for its implementation - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: detection and selection of them in the fire service, and/or at the control station of monitoring among other signals and interference noise in a predetermined frequency range. The device implementing the proposed method comprises gas sensors 1.i (i = 1, 2, …, n), matching the amplifiers 2.i, analogue-to-digital converters 3.i, the microprocessor 4, the shaper 5 of light and sound alarm signals, the indicating light 6, the alarm sounder 7, the output 8 of the shaper 5 which is connected to the central concentrator of fire protection, the shaper of the modulating code 9, the driving oscillator 10, the phase manipulator 11, the power amplifier 12, the transmitting antenna 13, the receiving antenna 14, the high frequency amplifier 15, the beat-frequency oscillator 16, the mixer 17, the intermediate frequency amplifier 18, the phase-splitting circuit 19 into two, the narrow-band filters 20 and 22, the phase doubler 21 and 28, phase shifter 23 by 90°, the phase detector 24, the registration unit 25, the search unit 26, the detector 27 of FMn-signal, the measuring devices 29 and 30 of spectral width, the inverter 31 of spectral width 32 to amplitude, the subtraction unit 33, the threshold unit 34, the key 35, and the delay line 36.

EFFECT: increase in reliability of early fire detection simultaneously at several sites of fire safety by transmitting alarm signals at different frequencies of search.

2 cl, 5 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 fire detection methods and apparatus (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. 9.948.070; 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 of early detection of fire and a device for its implementation" (RF patent No. 2.340.002, G08B 17/117, 2007), which are selected as the base objects.

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.

However, all fire safety objects transmit alarms on the same carrier frequency, which creates certain technical difficulties in those cases when alarms are simultaneously received by the fire department and / or the control room from several fire safety objects. In this situation, the reliability of early fire detection at the same time at several fire safety facilities decreases.

An object of the invention is to increase the reliability of early detection of fire at the same time at several fire safety facilities by transmitting alarms at different frequencies, searching, detecting and selecting them in the fire service and / or at a dispatching observation point among other signals and interference in a given frequency range.

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 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 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 coincide with gas concentration ratios. Along with the alarm, the high-frequency oscillation and the 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 department, they are frequency-converted, phase-divided by two, harmonic oscillation at a frequency w _pr / 2 is distinguished, its phase is doubled, this oscillation is distinguished at a prom daily frequency W _CR , 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 nearest analogue in that it searches for signals in a given frequency range by periodically tuning the local oscillator frequency, double the voltage phase of the intermediate frequency, measure the width of the spectrum of the received signal at weft frequency and its second harmonic is converted spectral width values in the amplitude, the difference of said amplitude, comparing it with a threshold level and if it is exceeded decide the detection of a complex signal with phase shift keying, the termination of the local oscillator frequency adjustment at time τ _s, the required for synchronously detecting a detected complex signal with phase shift keying, and allowing synchronous detection of a detected complex signal with phase shift keying, Over time τ _h continue tuning the frequency of the local oscillator and the search for signals in a given frequency range.

The problem is solved in that 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 is connected through a series-connected matching amplifier and an analog-to-digital converter to a microprocessor connected to an alarm conditioner and designed to compare the current values of the concentrations of gas components measured by the sensors with the simultaneous formation of the ratio th current concentration values and comparing the formed relation with its predetermined value, a master oscillator, a phase manipulator, the second input of which is connected to the second microprocessor output by a modulating code generator, a power amplifier and a transmitting antenna, are connected to the second output of the microprocessor, and at the control room / or in the fire department, a high-frequency amplifier, a mixer, the second input of which is connected to the output of a local oscillator and an intermediate-frequency amplifier, the first phase doubler, the second narrow-band filter, a 90 ° phase shifter, a phase detector, the second input of which is connected to the output of the intermediate-frequency amplifier, and the recording unit differs from the closest analogue to the output of the phase divider into two are serially connected that it is equipped with a search unit, a second phase doubler, two spectrum width meters, two spectrum width to amplitude converters, a subtraction unit, a threshold block, a key and a delay line, and to the output the intermediate frequency amplifier is connected in series with the first spectral width meter, the first spectral width to amplitude converter, a subtraction unit, a threshold block, the second input of which is connected to its output via a delay line, and a key, the second input of which is connected to the intermediate frequency amplifier output, and the output connected to the output of the phase divider by two, to the output of the intermediate frequency amplifier, a second phase doubler, a second spectral width meter and a second spectrum width converter are connected in series amplitude, whose output is connected to the second input of the subtractor, the local oscillator control input via the scan unit connected to the output of the threshold unit.

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 structural diagram of a device for early fire detection is presented in figure 3. The block diagram of a device for receiving a complex signal with phase shift keying, containing information about objects where a fire occurs, is presented in figure 4. Timing diagrams explaining the principle of operation of the devices shown in figure 5.

A device for early fire detection contains n channels, each of which is designed to measure the concentration of one gas component and contains a sensor in the form, for example, of a gas sensor 1.i (i = 1, 2, ..., n), to which a matching one is connected 2.i amplifier and analog-to-digital converter 3.i. The output of each analog-to-digital converter 3i 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 mixer 17, the second input of which is connected to the local oscillator 16 output, an intermediate frequency amplifier 18, a first spectral width meter 29, and a first width transformer 31 spectrum in amplitude, subtraction unit 33, threshold block 34, the second input of which is connected to its output through the delay line 36, the key 35, the second input of which is connected to the output of the intermediate frequency amplifier 18, phase divider 19 There are two, the first narrow-band filter 20, the first phase doubler 21, the second narrow-band filter 22, the 90 ° phase shifter 23, the phase detector 24, the second input of which is connected to the output of the intermediate frequency amplifier 18, and the registration unit 25. To the output of the intermediate frequency amplifier 18, a second phase doubler 28, a second spectrum width meter 30, and a second spectrum width to amplitude converter 32 are connected in series, the output of which is connected to the second input of the subtraction unit 33. The control input of the local oscillator 16 through the block 26 search is connected to the output of the threshold block 34.

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 Sieger (Germany), MICS 1110 from Motorola (USA), microprocessors like P1C 12C509 -A of Motorola, standard AD9202 ADCs of 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 release 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, carbon dioxide and aromatic hydrocarbons in the air in the first few minutes after the start of smoldering of 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%.

Analysis of the graphs shows that during the first minutes of smoldering, there is a sharp gas evolution of several gases simultaneously. Namely, hydrogen, carbon monoxide, carbon dioxide and aromatic hydrocarbons. The values of the concentration of emitted gases for different combustible materials can 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:

To _CxHy : To _H2 : To _CO : To _CO2 = 1: 1.5-2.5: 6.0-8.5: 4.0

Moreover, the values of the ratios 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 concentration of the main gas components are selected as the specified ratios of quantities with which the ratio of the current concentration values 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 action of one of the listed gas components (H ₂ , CO, CO ₂ and C _x H _y ), changes its conductivity with a change in the concentration of this gas component in the air. Then this signal is amplified and converted using a suitable 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: light, sound, as well as a signal supplied from output 8 to the central fire protection concentrator, and a modulating code M (t) that displays the identification fire safety facility number, 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 _CxNu : K _H2 : K _CO : K _CO2 = 1: 2.6: 6: 3.7,

in the third minute:

To _CxNu : To _H2 : To _CO : To _CO2 = 1: 2,1: 5: 3.

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

K _H2 : K _CO = 1: 2.3,

and in the third minute:

K _H2 : K _CO = 1: 2.4

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

K _CxNu : K _H2 : K _CO : K _CO2 = 1: 1.6: 8: 3,

in the third minute:

To _CxNu : To _H2 : To _CO : To _CO2 = 1: 2.1: 7: 2.8.

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 (w _c t + φ _c ), 0≤t≤T _c ,

where V _c , w _c , φ _c , T _c is the amplitude, carrier frequency, initial phase, and duration of the high-frequency oscillation, which arrives at the second input of the phase manipulator, the first input of which is supplied with the modulating code M (t) from the output of the shaper 9 (Fig. .5, b) showing the identification number of the fire safety facility. At the output of the phase manipulator 11, a complex QPSK signal is generated (Fig. 5, c)

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

where φ _k (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M (t) (Fig. 5, b), and φ _k (t) = const at Кτ _э < t <(K + 1) τ _e and can change abruptly at t = Kτ _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 _c (T _c = N · τ _e ), which, after amplification in the power amplifier 12, enters the antenna 13 and is radiated by it.

Therefore, the alarm of each fire safety object is characterized by a carrier frequency and a modulating code that displays its identification number.

At the dispatching observation point and / or in the fire service, the search for PSK signals is performed by tuning the frequency of the local oscillator 16 in a given frequency range Df.

Received QPSK signal U ₁ (f) (Fig. 5, c) from the output of the receiving antenna 14 through the high-frequency amplifier 15 is supplied to the first input of the mixer 17, the second input of which supplies the voltage of the local oscillator 16 of a ramp

U _g (t) = V _g Cos (w _g t + πγt ² + φ _g ), 0≤t≤T _p ,

- скорость перестройки частоты гетеродина в заданном диапазоне частоты Df; Т_п - период перестройки.Where $$\gamma =\frac{df}{T_P}$$

- the frequency tuning frequency of the local oscillator in a given frequency range Df; T _p - the period of perestroika.

The search for complex PSK signals in a given frequency range Df is carried out by periodically tuning the frequency of the local oscillator 16 using the search unit 26, which can be used as a sawtooth voltage generator.

At the output of the mixer 17, voltages of combination frequencies are generated. The amplifier 18 is allocated the voltage of the intermediate (differential) frequency

U _pr (t) = V _pr · Cos [w _ave t + φ _a (t) + φ ² -πγ2e _etc.] 0≤t≤7T _s,

; w_пр=w_c-w_г - промежуточная частота; φ_пр=φ_с-φ_г,Where $$V_{PR}=\frac{\mathrm{one}}{2}{V}_c\cdot V_g$$

; w _CR = w _c -w _g - intermediate frequency; φ _CR = φ _s -φ _g ,

which is fed to the inputs of the first meter 29 of the spectrum width and the second phase doubler 28. The output of the latter produces the following voltage

U ₂ (t) = V ₂ Cos (2w _pr t + 2πγt ² + 2φ _pr ),

, в котором фазовая манипуляция уже отсутствует, так как 2φ_k(t)={0,2π}. Это напряжение поступает на вход второго измерителя 30 ширины спектра.Where $${\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2=\frac{\mathrm{one}}{2}{\mathrm{<figure-callout\; id="2"\; label="V\; P\; R"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">V\; </figure-callout>}}_{PR}^{}$$

, in which phase manipulation is already absent, since 2φ _k (t) = {0.2π}. This voltage is supplied to the input of the second meter 30 of the spectrum width.

The width of the spectrum Δf _{from a} complex QPSK signal is determined by the duration τ _{e of} its elementary premises

, $$\Delta f_c=\raisebox{1ex}{$\mathrm{one}$}\!\left/ \!\raisebox{-1ex}{${\tau }_{\mathrm{uh}}$}\right.$$

,

while the width of the spectrum of its second harmonic is determined by the duration T _{s of the} signal

, $$\mathrm{<figure-callout\; id="2"\; label="\Delta \; f"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{f}_{}{}_2=\raisebox{1ex}{$\mathrm{one}$}\!\left/ \!\raisebox{-1ex}{$T_c$}\right.$$

,

those. the width of the spectrum of the second harmonic of the signal is N times smaller than the width of the spectrum Δf _{c of the} input signal

. $$\raisebox{1ex}{$\Delta f_{\mathrm{<figure-callout\; id="2"\; label="c\; \Delta \; f"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">c\; </figure-callout>}}$}\!\left/ \!\raisebox{-1ex}{$\Delta f_{}$}\right.=N$$

.

Therefore, as a result of doubling the phase of a complex QPSK signal, its spectrum width “folds” N times.

The spectral width Δf _{c of the} complex QPSK signal and its second harmonic Δf ₂ are measured using meters 29 and 30 of the spectral width. The measured values of the spectrum width Δf _c and Δf ₂ are fed to the inputs of the transducers 31 and 32 of the spectrum width, in amplitude. At the output of the latter, voltages are formed whose amplitudes V _I and V _{II are} proportional to the spectral width Δf _c and Δf ₂ , respectively (V _I = Δf _c , V _II = Δf ₂ ). Since Δf _c >> Δf ₂ , then V _I >> V _II . The amplitudes V _I and V _II are fed to two inputs of the subtraction unit 33, at the output of which a difference is formed

ΔV _I -V _II ,

which is compared with the threshold level of V _pores in the threshold block 34. The threshold voltage of V _pores is selected so that it is not exceeded by random noise, noise, and other false signals.

When the threshold level V _{pores is} exceeded (ΔV> V _pores ), a constant voltage is generated in the threshold block 34, which is supplied to the control input of the key 35, opening it, to the control input of the search unit 26, turning it off, and to the input of the delay line 36, the delay time τ _of which is selected so that it was possible to process and record the detected QPSK signal. In the initial state, the key 35 is always closed.

With false signals (interference) ΔV≈0 and key 35 does not open.

Therefore, the second phase doubler 28, the spectral width meters 29 and 30, the amplitude-to-amplitude converters 31 and 32, the subtracting unit 33, the threshold block 34, the key 35, and the delay line 36 form a detector of PSK signals 27 and provide for their selection among other signals and interference in a given frequency range Df.

Upon termination of the frequency tuning of the local oscillator 16 by the intermediate frequency amplifier 18, the following voltage is released (Fig. 5, g)

_Pr1 U (t) = V _pr · Cos [w _ave t + φ _a (t) -πγ2t ² _pr + φ] 0≤t≤T _s,

which through the public key 35 enters the input of the phase divider 19 into two, at the output of which a harmonic voltage is generated (Fig. 5, d)

U ₃ (t) = V ₃ · Sin (w _{pr / 2} t + φ _k (t) + φ _{pr / 2} ), 0≤t≤T _s ,

where V ₃ = 0.707 V 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 (w _{pr pr} t + φ) 0≤t≤T _s,

,Where $$V_{\mathrm{four}}=\frac{\mathrm{one}}{2}{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_3^2$$

,

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 (w _pr t + φ _pr + 90 °) = V ₄ · Cos (w _pr t + φ _pr ), 0≤t≤T _s ,

which is used as the reference voltage and is fed to the reference input of the phase detector 24, the information input of which receives the PSK signal at an intermediate frequency U _pr (t) (Fig. 5d) from the output of the intermediate frequency amplifier 18.

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 ,

,Where $$V_n=\frac{\mathrm{one}}{2}{V}_{PR}\cdot V_{\mathrm{four}}$$

,

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

After the time τ _{3, the} voltage from the output of the delay line 36 is supplied to the second (control) input of the threshold block 34 and resets its contents to zero. In this case, the key 35 is closed, and the search unit 26 is turned off, i.e. they return to their original state.

When the next complex QPSK signal is detected, which belongs to another fire safety object and has a different carrier frequency, the device operates in a similar way.

For the timely transmission of an alarm signal from fire safety facilities to the fire department and / or to the control room, radio channels and complex signals with phase shift keying are used.

In the well-known A. A. Pistolkors circuit, which also provides the selection of the reference voltage necessary for the synchronous detection of the received QPSK signal directly from the signal itself, the phenomenon of “reverse operation” is present. This is explained by the fact that in this circuit, due to the doubling of the frequency, phase manipulation is completely eliminated, 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 the phenomenon of “reverse operation” 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 PSK signal at an intermediate frequency is fed to a phase divider by two, and not to a frequency doubler. Therefore, the QPSK signal is not completely destroyed, but only its phase deviation decreases. As a result, an intermediate frequency oscillation is formed, which is hard-in-phase with the PSK signal. The latter eliminates the phenomenon of “reverse operation” and increases the reliability of the allocation of low-frequency voltage proportional to the modulating 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 gas leakage from cylinders, tanks or pipelines located inside or near the protected premises.

Thus, the proposed method and device in comparison with prototypes and other technical solutions of a similar purpose provide an increase in the reliability of early fire detection simultaneously at several fire safety facilities. This is achieved by transmitting alarms at different frequencies simultaneously from several fire safety facilities. At the same time, at the control room and / or in the fire service, they search, detect and select complex PSK signals among other signals and interference in a given frequency range.

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.

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 a complex 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.

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 indicated 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 a 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 in frequency, divide in phase into two, isolate harmonic oscillation at a frequency w _{pr / 2} , double its phase, isolate harmonic oscillation in the intermediate frequency w _CR , 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, characterized in that it searches for signals in a given range frequency by periodically tuning the local oscillator frequency, double the voltage phase of the intermediate frequency, measure the spectrum width of the received signal at the intermediate frequency and its sec harmonics, they convert the spectral width values to the corresponding amplitudes, determine the difference between the indicated amplitudes, compare it with the threshold level and, if it is exceeded, decide to detect a complex signal with phase shift keying, stop tuning the local oscillator frequencies for the time τ _s necessary for synchronous detection of the detected complex signal with phase shift keying, and resolution of synchronous detection of the detected complex signal with phase shift keying, when the time τ _of continuing tuning of the frequency oscillator and to search a predetermined frequency range signals. 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 predetermined value, a master oscillator, a phase manipulator, the second input of which is connected to the second microprocessor output by a modulating 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 mixer, the second input of which is connected to the local oscillator output, and an intermediate amplifier are connected in series to the output of the receiving antenna of the second frequency, the first narrow-band filter, the first phase doubler, the second narrow-band filter, the 90 ° phase shifter, the phase detector, the second input of which is connected to the output of the intermediate frequency amplifier, and the recording unit, which is different in that it equipped with a search unit, a second phase doubler, two spectrum width meters, two spectrum width to amplitude converters, a subtraction unit, a threshold block, a key and a delay line, with the intermediate output to the amplifier a frequency meter, a first spectral width to amplitude converter, a subtraction unit, a threshold block, the second input of which is connected to its output via a delay line, and a key, the second input of which is connected to the output of the intermediate frequency amplifier, and the output is connected to the input a phase divider by two, a second phase doubler, a second spectral width meter and a second spectrum width to amplitude converter, the output of which is connected to the output of the intermediate frequency amplifier connected to the second input of the subtractor, the local oscillator control input via the scan unit connected to the output of the threshold unit.

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