JPS6296846A - Particulate detector - Google Patents

Abstract

PURPOSE:To make it possible to measure samples at many points simultaneously, by arranging laser oscillators at the sides of a regular (n) polygon, arranging mirrors at the apexes thereof, arranging sample air between them, and detecting scattered laser light projected on particulates in the air. CONSTITUTION:Three mirrors 1, which are arranged on the apexes of a regular (n) polygon (n is an integer of 3 or more), e.g., a regular triangle, are 100% reflecting mirrors. Laser light beams are sent from two laser tubes 2 and reaches the three apexes of the regular triangle through sample air 12 from the two directions. The position is determined so that the incident angles thetaof the laser light beam become equal. In a particulate detector 1 formed in this way, from both ends of the laser tube 2, which is arranged on each side of the regular triangle, the laser light beam is sent to the direction of the apexes. Six detectors 3 are arranged between the laser tube 2 and the apexes. The detectors detect the particulates in the sample air through the scattered light of the laser light sent from the laser tube 2. The detected signals are sent to a measuring circuit 4. Thus the measurements at many points can be performed by only one particulate detector.

Description

Detailed Description of the Invention [Field of Application in Industry-1-] The present invention relates to a particle detection device for measuring the cleanliness of air (hereinafter referred to as sample air) in a predetermined location.

[Prior Art] Conventionally, as a device for measuring the cleanliness of sample air, a laser beam is emitted onto the sample air, and fine particles in the sample air are detected by light scattering detection (4) through the scattered light of the laser beam.
There is a so-called light scattering particle detector that detects particles using a light scattering cell.

[Problems to be Solved by the Invention] However, in such conventional light scattering particle detectors, only one light scattering detector is disposed in one laser oscillator, making it difficult to perform multi-point sampling. To perform this simultaneously, multiple particulate detection systems are required, and 1
In order to perform multi-point sampling using a single particle detector, there is a problem in that the sample points must be switched to time-series points using a solenoid valve or the like. Furthermore, when measuring a large amount of sample air, it is necessary to increase the laser power, which causes the problem that the laser oscillator becomes human-like.

[Object of the Invention] 1-1 of the present invention is to solve the above-mentioned conventional problems and to provide a fine particle detection device.

[Means for Solving the Problems] The -P stage of the present invention for achieving the above-mentioned objective is to n or 2n laser oscillators arranged to emit laser beams in the direction of each vertex of the regular n-gon; 2n detectors for detecting through scattered light, n mirrors arranged at each vertex, and 51 of the particles in total according to the detection signal from the detectors, 7! the mirror is positioned such that the incident angles of the laser beams from two directions that pass through the sample air and reach the one point are equal; be.

[Operation] The particle detection device configured in this manner is configured to detect laser oscillators from n or 2n laser oscillators arranged on each side of a regular n-gon, +1: on both ends of each side, each"
Laser light is transmitted 111 in a single point direction. Then, 2n detectors placed between each laser beam oscillator and each point detect fine particles r in the sample air through the scattered light of the laser beam sent out from each laser oscillator. Then,
The acid in the fine particles is measured by a -1 constant circuit according to the detection signal from each detector. Furthermore, n mirrors are arranged at each vertex of the 1Erx rectangle, and each mirror is positioned so that the incident angles of the laser beams from two directions passing through the sample air and reaching each vertex are equal. Therefore, each laser beam from two directions that passes through the sample air and reaches each mirror is reflected by each laser beam that enters from the other direction. This increases the laser power between each laser oscillator and each vertex. Since 2n detectors are arranged in this particle detection device, sampling at multiple points can be performed simultaneously. Also, if you sample the same number of points with 21 detectors, you will be amazed! The same effect as using a laser can be obtained.

[Example] Hereinafter, an example of the particle detector according to the present invention will be described in detail with reference to the drawings.

1 to 3 show embodiments of a particle detection device according to the present invention.

As shown in FIG. 1, this particle P detection device 1 has the shape of an equilateral triangle, which is a regular n-gon, with one laser tube 2 as a laser oscillator arranged on each of three sides.

These three laser tubes 2.2.2 emit laser light from both ends, and by being placed on the three sides of an equilateral triangle, it is possible to It emits laser light in the direction of a triangular reconnaissance point.

A total of six detectors 3 are arranged on both sides of the three laser tubes 2.2.2, with one detector 3 arranged directly between each point of the equilateral triangle.

As shown in FIG. 2, these six detectors 3 detect sample air 12 (see FIG. 3! 1. ), each detector 3 is connected to a measuring circuit 4.
It is connected to the.

The measurement circuit 4 includes a number of amplifiers 5 corresponding to the number of detectors 3, a particle size discrimination circuit 6, a counter 7, and a display circuit 8.

Amplification 7! A5 is for amplifying the signal sent from the detector 3, and the particle size discrimination circuit 6 classifies the particulates into six groups according to particle size according to the signal amplified by the amplifier 5. This is to send out each signal to the counter 7.

The counter 7 also receives the 6
It has six channels corresponding to signals for each of the six divisions, counts the amount of fine particles according to particle size for each of the six divisions, and sends this signal to the display circuit 8, which The count value of the counter 7 is displayed in response to this signal.

Note that the measurement circuit 4 includes an addition circuit 9 and a switching circuit 10.

The adder circuit 9 includes six amplifiers 5 and six particle size discrimination circuits 6.
Based on the sending signal from one detector 3 selected from the six detectors 3, the signals are added to perform particle size discrimination by one of the six particle size discrimination circuits 6. A signal is sent to the circuit 6 via the switching circuit 10. This switching circuit 10 is connected to the one particle size discrimination circuit 6, and performs switching for connecting this particle size discrimination circuit 6 to the detection V913 or the addition circuit 9.

Now, this particulate detection device 1 has the shape of an equilateral triangle, and three mirrors 11. It is equipped with tt and ti.

These three mirrors 11, 11.11 are 100% main reflection, and as shown in FIG. 2 and FIG.
The laser beams are positioned so that the incident angles 0 of the laser beams from two directions reaching one point of the three equilateral triangles are equal.

The particulate detection device 1 configured in this way has an equilateral triangular shape, and a laser beam is emitted from both ends of three laser tubes 2.2.2 arranged on each side l- of the equilateral triangle in the direction of force at each square point of the equilateral triangle. Light is sent out. Then, six detectors 3 arranged between each laser tube 2.2.2 and each vertex are connected to each laser tube 2.2.2.
．． Particles in the sample air 12 are detected through the scattered light of the laser beam sent out from the sample air 12.

Each of the six detectors 3 sends a detection signal of the fine particles to the measurement circuit 4.

The detection signal sent to this measurement circuit 4 is first amplified?
It is amplified by A5. Then, the particle size discrimination circuit 6 classifies the fine particles into six categories according to the particle size, and signals for each of the six categories are sent to the counter 7. The counter 7 counts the amount of fine particles -r in each of the six sections using six channels, and this signal is sent to the display circuit 8, where the count value is displayed on the table t% circuit 8.

Facing each other, 6 sample air points are simultaneously sampled per point.
u11 will be determined.

Next, when measuring the same number of sample air with a large suction amount, combine the six sample air introductions 11 (see figure 1 < not shown) into one sample air in the same atmosphere. are introduced equally into the six detectors 3. Then, one detector 3 selected from the six detectors 3
Based on the output signal from the O/L diameter discrimination circuit 6, the summed signal is ORed and the added signal is output to one of the six O/L diameter discrimination circuits 6.

The switching circuit 10 in this case is connected to the addition circuit 9 and connects the particle size discrimination circuit 6 and the addition circuit 9.

The switching circuit 10 is connected to an amplifier 5 when measuring multiple sample air points one by one, and connects the particle size discrimination circuit 6 and the detector 3 via the amplifier 5. .

Thus, the sample air of multiple points and the same number of points is sampled by the particle detection device 1, but this particle detection device 1 is arranged at each vertex of this regular square in the E ball shape. It is equipped with three mirrors 11, 11.11, and these three mirrors 11, 11.11 are
0% reflective mirror, each mirror 11.11.11 is 2
Since the laser beams from each direction are positioned so that the incident angles θ are equal, each laser beam that reaches each mirror 11゜11.11 from two directions will be Reflects on laser light.

From this, the laser power increases between each laser tube 2.2.2 and each m point of the IF regular pentagon, and the oscillation efficiency of the laser beam increases.

[Below]-1 Example has been described, but the laser tube is not limited to being arranged on each side of a regular pentagon shape, but it can also be arranged on each side of a regular square, regular pentagon, etc. shape. Good too. In this case, the number of detectors and mirrors corresponding to the shape of a regular square, regular pentagon, etc. are arranged.

In addition, the oscillator is not limited to a laser tube,
Two oscillators that emit laser light in one direction are placed back to back on each side, and each n'1 point of a regular n-gon is placed in the same direction.
Alternatively, the light may be sent out.

[Effects of the Invention] As is clear from the following explanation, the particle detection device of the present invention is arranged on each side of an 11-sided polygon (n is an integer of 3 or more), and : IX or 2n laser oscillators that emit laser beams in the direction of each vertex of an n-gon, and these laser oscillators and each of the "+1ii"
2n detectors arranged between one point and detecting particles in the sample air through scattered light of the laser beam;
n mirrors disposed at each of the vertices, and a measurement circuit that measures the amount of mll fine particles in accordance with a detection signal from the detector; Since the laser beams arriving at the point are positioned so that the incident angles from the two directions are equal,
Multiple points can be sampled simultaneously with one device.
A large amount of sample air can be measured without increasing laser power, and it is compact.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing one embodiment of the particle detection device according to the present invention, Fig. 2 is an enlarged view of one point in Fig. 1, and Fig. 3 is a sample irradiated with laser light. It is an explanatory diagram showing air. 1...Several grain r detection device, 2-...Laser tube, 3 song detection lines, 4...Measuring circuit, 9 song addition circuit, 10-...
Switching circuit, 11...mirror.

Claims (3)

[Claims] (1) n or 2n laser oscillators arranged on each side of a regular n-gon (n is an integer of 3 or more) and transmitting laser beams in the direction of each vertex of the regular n-gon; 2n detectors arranged between a laser oscillator and each of the vertices to detect particles in the sample air via scattered light of the laser beam, and n mirrors arranged at each of the vertices; a measurement circuit that measures the amount of the particles according to a detection signal from the detector, and the mirror is configured to receive each of the laser beams from two directions so as to pass through the sample air and reach each of the vertices. A particle detection device characterized by being positioned so that the angles are equal. (2) The laser oscillators are n laser tubes placed on each side and emit laser beams from both ends, and the measurement circuits are 2n laser tubes individually connected to 2n detectors. a particle size discrimination circuit, a counter connected to the particle size discrimination circuit, and a display circuit for displaying a count value, and the particle size discrimination circuit is configured to perform a predetermined detection according to a signal sent from the detector. The method is characterized in that the fine particles are classified by particle size and a signal for each classification is sent to the counter, and the counter counts the fine particles by particle size based on this signal and sends the signal to the display circuit. A particulate detection device according to claim 1. (3) The measurement circuit includes an adder circuit and a switching circuit connected between the 2n detectors and the 2n particle size discrimination circuits, and the adder circuit is connected between the 2n detectors and the 2n particle size discrimination circuits. Adding the signals based on the sending signals from any one or more selected from among them and sending the signal to one of the 2n particle size discrimination circuits via the switching circuit, 3. The particle detection device according to claim 2, wherein said one particle size discrimination circuit is switched to connect said one particle size discrimination circuit to said detector or said addition circuit.