JPH0222333B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cross-flow type infrared gas analyzer that modulates the detection output and analyzes the measured gas by flowing zero gas and measuring gas alternately through two cells. Failure of the optical system such as dirt on the cell window, shorting of the detector capacitor film, etc.
The present invention relates to a device that determines operational abnormalities caused by electrical system failures such as shorts and disconnections in applied voltage wires, and amplifier failures.

When multiple analyzers are operated as one system, if an abnormality occurs in the operation of even one analyzer, it is desirable to notify the observer of the abnormality immediately, and to notify the observer of the abnormality. It is desirable to be able to identify the problem in order to enable prompt repair. Furthermore, even when a single analyzer is in operation, it is desirable to be able to identify whether the failure location is within the analyzer or in the sampling system outside the analyzer.

The present invention aims to issue an alarm only when there is an abnormality within the analyzer to notify the operator of the abnormal operation and to identify the abnormality.

The following will explain based on the drawings. Figure 1 shows an embodiment of the present invention, in which 1 is a cross-flow type infrared gas system in which zero gas and measurement gas are alternately flowed into two cells 2 and 3 to modulate the detection output and analyze the measurement gas. The analyzer includes the cells 2 and 3, light sources 4 and 5 for irradiating each cell with light, a detector for detecting the light transmitted through each cell 2 and 3, such as a condenser microphone type detector 6, and the detection device. A selective amplifier 7 selectively amplifies only the signal in the component region equal to the gas flow path switching frequency out of the output of the device 6. Note that the gas flow path switching frequency is a switching frequency between the zero gas and the measurement gas that are alternately flowed into the two cells.

8 is a DC power source for causing the light sources 4 and 5 to emit light, and 9 is a biasing means for biasing the current passed from the power source 8 to each of the light sources 4 and 5 at a predetermined period. In the illustrated example, two transistors Tr ₁ ,
It consists of Tr ₂ and one resistor R. Each of the transistors Tr ₁ and Tr ₂ is alternately turned on and off by a synchronization signal generated from a synchronization signal generator 10. When one transistor Tr ₁ is turned on, the resistor R is connected in parallel with one of the light sources 4, and the current flowing through the light source 4 is shunted, so that the light emission energy of the light source 4 is reduced. At this time, the emission energy of the other light source 5 usually increases. On the other hand transistor
When Tr ₂ becomes conductive, the resistor R is connected in parallel with the light source 5, so that the light emission energy of the light source 5 decreases.
The degree of reduction in the emission energy of each light source 4, 5 is appropriately determined by selecting the value of the resistor R.

The cycle of turning on and off the transistors Tr ₁ and Tr ₂ , that is, the cycle of the synchronization signal, is set equal to the gas flow path switching cycle. The signal is then amplified through a selection amplifier 7 that amplifies only the signal component that matches the gas switching frequency. Reference numeral 11 denotes a command unit consisting of, for example, a push button, and only when this push button is pressed, the synchronization signal generator 10 operates to generate a synchronization signal. Therefore, the currents of the light sources 4 and 5 are not biased unless the push button is pressed. 12 is a memory that stores a predetermined judgment reference value; 13 is a memory that stores this judgment reference value and a simulated signal output from the selection amplifier 7 (a signal obtained when the currents of the light sources 4 and 5 are biased); )
This is a determiner that compares the spectrometer and determines whether the analyzer's operation is normal or abnormal based on the comparison results. In the illustrated example, this determiner 13 includes a V-F converter 14 that converts a voltage signal into a frequency, and a counter 15 that counts pulses appearing in its output. It consists of a matching circuit 16 for judging. This matching circuit 16 is configured to determine that there is a match if the difference between both values is within a predetermined value. Reference numeral 17 denotes an alarm means for issuing an alarm when the determiner 13 determines that there is an abnormality in operation, and a means that appeals to the senses such as a lamp or something that appeals to the senses such as a buzzer is used.

Next, the operation of determining abnormal operation of the analyzer using the apparatus having this configuration will be explained. First, the measurement gas in the cell is replaced with zero gas, so that both cells 2 and 3 contain zero gas. Next, push button 1
1 is pressed to operate the biasing means 9 and change the emission energy of the light sources 4 and 5 at a predetermined period. At this time, since there is no abnormality in the optical system or electrical system within the analyzer, the emitted light energy of each light source 4, 5 passes through each cell 2, 3 as it is and enters the detector 6, and the emitted light energy of each light source The amount of charge stored in the capacitor film is changed according to the change in . A current based on this change in the amount of accumulated charge is input to the selection amplifier 7. This current is changing at a frequency biased by the biasing means 9, and since the frequency is the same as the gas flow path switching frequency, it is amplified as it is in the selection amplifier 7 and is added to the determiner 13 as a simulated signal. and compared with the judgment reference value.

The judgment reference value is set to a value that corresponds to a simulated signal when the analyzer is operating normally.
The determiner 13 determines that the analyzer is operating normally. Further, even if there is an abnormality in the sampling system outside the analyzer at this time, the cell contains zero gas, so the abnormality in the sampling system will not affect the above determination operation.

On the other hand, if there is an abnormality within the analyzer, for example, if there is an abnormality in the optical system such as deterioration of the light source or dirt on the cell window, the change in the amount of accumulated charge in the detector 6 will be larger than normal due to the abnormality. Or become smaller.
Therefore, the simulated signal amount at that time no longer matches the determination reference value, the determiner 13 determines that the operation is abnormal, and the alarm means 17 issues an alarm. Similarly, if there is an abnormality in the electrical system, such as a capacitor membrane short or an amplifier failure, the simulated signal may not be generated at all, or the amount of the signal may be larger or smaller than in normal conditions. Therefore, the determiner 13 determines that the operation is abnormal, and the alarm means 17 issues an alarm.

In this embodiment, the simulated signal is created by alternately biasing the two light sources 4 and 5, but the simulated signal has a difference in the emission energy of the two light sources, and the difference is determined by a predetermined period. Since it is possible to create a light source as long as the polarity changes in the direction of current, it is also possible to adopt a structure in which the two light sources have asymmetrical deviations (with respect to the deviation from the DC level). Therefore, the circuit configuration shown in FIG. 2 can also be implemented as a biasing means.

In addition, if the above determination device determines that the analyzer is malfunctioning, it means that the analyzer in which the device is installed is malfunctioning, but it may be due to an abnormality in the optical system within the analyzer or an abnormality in the electrical system. It is not possible to determine the size. Therefore, if such a determination is required,
A determining device shown in FIG. 3 may be provided in addition to the determining device described above. In FIG. 3, reference numeral 18 denotes a DC high-voltage power supply provided in the analyzer for applying voltage to the detector, 19 denotes biasing means for biasing the voltage of this power supply 18 at the same frequency as the gas flow path switching frequency, and 20 denotes this biasing means. 19
21 is a command section consisting of a push button, 22 is a memory for storing judgment reference values, 23 is a judge, and 24 is an alarm means. These 22, 23, 24 can have the same configuration as 12, 13, 17 shown in FIG.
4 also serves as the one shown in FIG.
It is also possible to implement a configuration in which only 2 and 22 are switched and used. This determination device biases the high-voltage DC voltage applied to the detector 6 at a predetermined period by a biasing means 19, thereby changing the amount of accumulated charge generated in the capacitor film of the detector, and making a selection based on the change. The simulated signal output from the amplifier 7 is compared with a determination reference value.

Therefore, according to this determination device, the short of the capacitor film of the detector 6, the short of the applied voltage wire,
It is possible to determine only abnormalities in the electrical system, such as wire breakage and failure of the selective amplifier 7. Therefore, by using this judgment device together with the judgment device shown in Fig. 1,
It is possible to identify whether there is an abnormality in the optical system or the electrical system within the analyzer.

Since the present invention is configured as explained above, when a plurality of analyzers are operated as one system, abnormal operation may occur as long as the device of the present invention is installed in each analyzer. The analyzer can be quickly discovered, and even when only one analyzer is in operation, it is effective in determining whether an abnormality is inside the analyzer or outside the analyzer. In addition, when checking for abnormal operation of the analyzer, it is sufficient to simply replace the measurement gas in the cell with zero gas, and there is also the advantage that there is no need to stop the operation of the analyzer. Furthermore, since the current of the light source is biased by a biasing means including a switching element made of a semiconductor element, a continuous action with a fast cycle is possible, and abnormal operation can be quickly and accurately determined. There are some advantages.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a diagram showing another specific example of the biasing means, and FIG.
The figure shows a determination device that can be used in combination with the device of the present invention. 2, 3... Cell, 4, 5... Light source, 6... Detector, 9... Biasing means, 13... Judgment device, 17...
Alarm means.

Claims (1)

[Claims] 1 Cross-flow type infrared rays equipped with two cells in which measurement gas and zero gas flow alternately, two light sources that irradiate light to each of these two cells, and a detector that receives the light transmitted through the two cells. In the gas analyzer, the light sources are connected in series with each other, and the current of at least one of the light sources is caused to flow through the two cells by a biasing means including a switching element made of a semiconductor element, the same as the gas switching period. A simulated signal output from the analyzer while biasing the current of the light source is compared with a predetermined reference value to determine whether the operation of the analyzer is normal or abnormal, and an alarm is issued in the event of an abnormality. An operation abnormality determination device for a cross-flow type infrared gas analyzer, characterized in that the device emits an infrared gas analyzer.