Particle scattered light signal amplification and counting circuit, method and particle counter

Abstract

The present application discloses a particle scattered light signal amplification and counting circuit, method, and particle counter, relating to the field of particle counting. The circuit includes: a photodetector, a preamplifier circuit, multiple voltage comparators, and multiple counters. It also includes: multiple amplifier circuits; the amplifier circuits, voltage comparators, and counters correspond one to one; the preamplifier circuit is connected to the photodetector; each amplifier circuit is connected to the preamplifier circuit; wherein each amplifier circuit corresponds to a different preset magnification; each voltage comparator is connected to a corresponding amplifier circuit; and each counter is connected to a corresponding voltage comparator. In this circuit, the corresponding particle signal is amplified by different magnifications through the amplifier circuit, achieving differentiated processing of the particle signal, reducing the requirement for the maximum output voltage of the amplifier circuit, reducing the energy consumption of the device, and improving the accuracy of the particle counter.

Description

Technical Field

[0001] The present application relates to the field of particle counting, and in particular to a particle scattered light signal amplification and counting circuit, method, and particle counter. Background Art

[0002] Particle counters monitor scattered light from particles and convert it into voltage pulse signals, which are then identified and classified by particle size. Particle counters typically include multiple size standards, with particles larger than a certain size being counted. Specifically, the particle scattered light signal is converted into a photocurrent and then further into a voltage pulse signal. After multiple rounds of amplification, filtering, and noise reduction, the particle signal is obtained. After identifying the particle signal, the particle is counted according to the size classification.

[0003] To identify small-sized particles, the particle signal needs to be amplified at a high factor. For example, the scattering intensity of Mie scattering is positively correlated with the cube of the particle size, and the signals of particles of different sizes produce orders of magnitude differences after amplification. Using the same amplification factor for particles of different sizes, while being able to identify particles of the smallest size, the amplification factor signal value for particles of the largest size differs significantly from that of particles of the smallest size. This places higher demands on the maximum output voltage of the circuit and increases the energy consumption of the device. The heat generated by the high energy consumption of the device also reduces the accuracy of the particle counter.

[0004] It can be seen that how to provide a solution to the above technical problems is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a particle scattered light signal amplification and counting circuit, method and particle counter, which are used to prevent the problem that when the electrical signals of scattered light of particles of different particle sizes are amplified by the same multiple, the amplifier circuit is required to have a higher output voltage to prevent particle signal output saturation, and the energy consumption of the equipment is increased. At the same time, the heat environment caused by high energy consumption leads to a reduction in the accuracy of the particle counter.

[0006] To solve the above technical problems, the present application provides a particle scattered light signal amplifying and counting circuit, comprising: a preamplifier circuit connected to the output end of a photodetector in a particle counter, a plurality of voltage comparators, and a plurality of counters; and further comprising: a plurality of amplifier circuits; the amplifier circuits, the voltage comparators, and the counters are in one-to-one correspondence;

[0007] The photodetector is used to receive scattered light signals and convert the scattered light signals into photocurrent signals;

[0008] The preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit, and is configured to convert and amplify the received photocurrent signal by the transimpedance amplifier and then amplify the signal by the first signal amplification circuit to obtain a voltage pulse signal;

[0009] The input end of each amplifier circuit is respectively connected to the output end of the preamplifier circuit; and is used to amplify the voltage pulse signal by a preset multiple to form a corresponding particle signal; wherein each amplifier circuit corresponds to a different preset multiple;

[0010] The input end of each voltage comparator is connected to the output end of the corresponding amplifier circuit respectively; and is used to compare the particle signal with the threshold value in the voltage comparator and output a comparison result;

[0011] The input end of each counter is connected to the output end of the corresponding voltage comparator respectively, and is used to count according to the comparison result.

[0012] Preferably, the threshold value in each voltage comparator is preset based on the preset multiple of the corresponding amplification circuit and a preset particle size standard that the voltage comparator is preset to pass. The preset passing of the preset particle size standard that the voltage comparator is preset to pass here means that particles greater than or equal to the preset particle size standard can be counted by the counter corresponding to the voltage comparator, while particles smaller than the preset particle size standard will not be counted.

[0013] Preferably, it further comprises: a filter provided on the amplifying circuit, for filtering noise outside the particle signal and obtaining the filtered particle signal.

[0014] Preferably, the first signal amplifying circuit is used to amplify the signal after the photocurrent signal is converted and amplified by the transimpedance amplifier multiple times so as to obtain the amplified voltage pulse signal.

[0015] Preferably, the preset multiple is negatively correlated with the particle size.

[0016] In order to solve the above technical problems, the present application also provides a particle counter, including the above-mentioned particle scattered light signal amplifying and counting circuit.

[0017] In order to solve the above technical problems, the present application also provides a method for amplifying and counting particle scattered light signals, which is applied to a particle scattered light signal amplifying and counting circuit comprising a preamplifier circuit, multiple amplifying circuits, multiple voltage comparators, and multiple counters, wherein the amplifying circuits, the voltage comparators, and the counters correspond to each other one by one, the preamplifier circuit comprising a transimpedance amplifier and a first signal amplifying circuit for amplifying the received signal in the same circuit; the input end of each of the amplifying circuits is respectively connected to the output end of the preamplifier circuit; the input end of each of the voltage comparators is respectively connected to the output end of the corresponding amplifying circuit; the input end of each of the counters is respectively connected to the output end of the corresponding voltage comparator; the method comprises:

[0018] Converting the scattered light signal into a photocurrent signal by the photodetector;

[0019] The received photocurrent signal is converted and amplified by the preamplifier circuit through the transimpedance amplifier, and then amplified by the first signal amplification circuit to obtain a voltage pulse signal;

[0020] Amplifying the voltage pulse signal by a preset multiple through each amplifier circuit to form a corresponding particle signal; wherein each amplifier circuit corresponds to a different preset multiple;

[0021] Comparing the particle signal with a threshold value in the voltage comparator through each of the voltage comparators;

[0022] The comparison results of the voltage comparators are obtained through each of the counters, and counting is performed according to the comparison results.

[0023] The particle scattered light signal amplification and counting circuit provided in the present application includes: a preamplifier circuit connected to the output end of the photodetector in the particle counter, multiple voltage comparators, and multiple counters, and also includes: multiple amplification circuits; the amplification circuits, voltage comparators, and counters correspond to each other one by one; the photodetector is used to receive the scattered light signal and convert the scattered light signal into a photocurrent signal; the preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit, and is used to convert the received photocurrent signal through the transimpedance amplifier and then amplify it through the first signal amplification circuit to obtain a voltage pulse signal; the input end of each amplification circuit is respectively connected to the output end of the preamplifier circuit; it is used to amplify the voltage pulse signal according to a preset multiple to form a corresponding particle signal; wherein each amplification circuit corresponds to a different preset multiple; the input end of each voltage comparator is respectively connected to the output end of the corresponding amplification circuit; it is used to compare the particle signal with the threshold in the voltage comparator and output the comparison result; the input end of each counter is respectively connected to the output end of the corresponding voltage comparator; it is used to count according to the comparison result. In this circuit, the corresponding particle signal is amplified by different multiples through the amplifier circuit. For example, particles with large particle sizes can be amplified at a smaller multiple, and particles with small particle sizes can be amplified at a larger multiple. In other words, the particle signal is processed differentially, so that the requirement for the maximum output voltage of the amplifier circuit is reduced and the energy consumption of the device is reduced, thereby minimizing the occurrence of a situation where the accuracy of the particle counter is reduced due to the heating environment caused by the high energy consumption of the device, thereby improving the accuracy of the particle counter.

[0024] In addition, the present application also provides a method for amplifying and counting particle scattered light signals and a particle counter, which have the same or corresponding technical features as the above-mentioned particle scattered light signal amplifying and counting circuit and have the same effects as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic diagram of a particle scattered light signal amplification and counting circuit provided in this application;

[0027] Figure 2 A schematic diagram of a particle scattered light signal amplification and counting circuit for counting provided in an embodiment of the present application;

[0028] Figure 3 A flowchart of a method for amplifying and counting particle scattered light signals provided in an embodiment of the present application;

[0029] Figure 4 This is an overall flow chart of a method for amplifying and counting particle scattered light signals provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] The core of this application is to provide a particle scattered light signal amplification and counting circuit, method and particle counter, which are used to prevent the problem that when particles of different particle sizes are amplified by the same multiple, a higher output voltage is required for the amplifier circuit and the energy consumption of the equipment is increased. At the same time, the heat environment caused by high energy consumption leads to a reduction in the accuracy of the particle counter.

[0032] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods. Figure 1 This is a schematic diagram of a particle scattered light signal amplification and counting circuit provided in this application, such as Figure 1 As shown, the circuit includes: a preamplifier circuit 2 connected to the output end of the photodetector 1 in the particle counter, multiple voltage comparators 4, multiple counters 5, and also includes: multiple amplifier circuits 3; the amplifier circuits 3, voltage comparators 4, and counters 5 are in one-to-one correspondence;

[0033] The photodetector 1 is used to receive the scattered light signal and convert the scattered light signal into a photocurrent signal;

[0034] The preamplifier circuit 2 includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit. The preamplifier circuit 2 is used to convert and amplify the received photocurrent signal through the transimpedance amplifier, and then amplify it through the first signal amplification circuit to obtain a voltage pulse signal, so that the signal formed by the particles entering the particle counter is amplified in the same circuit.

[0035] The input end of each amplifier circuit 3 is connected to the output end of the preamplifier circuit 2 respectively; it is used to amplify the voltage pulse signal according to a preset multiple to form a corresponding particle signal; wherein each amplifier circuit 3 corresponds to a different preset multiple;

[0036] The input end of each voltage comparator 4 is connected to the output end of the corresponding amplifier circuit 3; it is used to compare the particle signal with the threshold value in the voltage comparator 4 and output the comparison result;

[0037] The input end of each counter 5 is connected to the output end of the corresponding voltage comparator 4 respectively, and is used to count according to the comparison result.

[0038] In this technical solution, the comparator outputs a signal to count particles that have passed a preset particle size standard or above, or outputs a signal to not count particles that are smaller than the preset particle size standard, and the corresponding particle counter counts or does not count according to the output of the comparator; as an implementable method, when the particle signal received by the voltage comparator is greater than the threshold used for comparison in the voltage comparator, the counter corresponding to the voltage comparator counts the number of particle signals, otherwise it does not count. No specific limitation is made here.

[0039] When particles are irradiated by a light beam, scattered light is generated. The scattered light signal is received by a photodetector and converted into a photocurrent signal. The photocurrent signal is then converted and amplified into a voltage pulse signal by a preamplifier circuit. The specific preamplifier circuit used is not limited. For example, the preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal within the same circuit. For signal identification, the greater the amplification factor, the better. Therefore, the preamplifier circuit includes a first signal amplification circuit. Since the signal based on the photocurrent signal is relatively small, in order to accurately identify the particles, in this embodiment, the received signal is amplified by the transimpedance amplifier and then amplified by the first signal amplification circuit to obtain a pre-amplified voltage pulse signal. If both the small particle signal and the large particle signal are amplified in the same circuit to obtain a particle signal capable of identifying the particle size, the circuit used for amplification is required to have a very high maximum output voltage. Therefore, pre-amplification is first performed in the same circuit to obtain a pre-amplified voltage pulse signal, which is then sent to each amplifier circuit. It should be noted that, assuming that the amplification factor of the preamplifier circuit is the first factor and the amplification factor of the amplifier circuit is the second factor, in general, the first factor is usually much larger than the second factor. The first factor may be more than tens of thousands of times, while the second factor may be only dozens or several times or even less than 1 times. The particle signal obtained by amplification according to the first factor can support large particles to be identified by the voltage comparator, but it is not enough to support small particles to be identified. Therefore, after passing through the first signal amplification circuit, the voltage pulse signal needs to be amplified again by the amplification circuit. The voltage pulse signal is uniformly amplified by the first signal amplification circuit. On the one hand, the particle signals of different particle sizes can be amplified. On the other hand, compared with the method of directly amplifying larger different factors, this embodiment amplifies the voltage pulse signal with a larger same factor and then amplifies it with a smaller different factor, which can more accurately count particles.

[0040] In the previous particle signal counting circuit, the voltage pulse signal is amplified by the same multiple through the amplifier circuit to form the corresponding particle signal. The particle signal is then passed through multiple voltage comparators and compared with the threshold of the voltage comparator. Counting is performed when the value is greater than the threshold. Because the voltage pulse signal in the previous particle signal counting circuit is uniformly amplified through the amplifier circuit, when particles with small particle sizes can be identified, the signal value of the particle with the largest particle size differs greatly from the signal value of the particle with the smallest particle size. This places high demands on the maximum output voltage value of the op amp in the amplifier circuit and requires the device to consume more energy. The heat generated by the high energy consumption of the device will also reduce the accuracy of the particle counter. Therefore, this embodiment performs differential processing on the scattered light signals of particles entering different voltage comparators, so that the difference between the signal value of the particle signal with the largest particle size and the signal value of the particle signal with the smallest particle size after amplification by the preamplifier circuit and the amplifier circuit is reduced.

[0041] Here, the first signal amplification circuit and multiple amplification circuits amplify the received signal by including one or more operational amplifiers (operational amplifiers), such as a common-mode amplifier circuit, an inverting amplifier circuit, a follower circuit, etc., which are used to amplify the signal. No specific restrictions are made here.

[0042] In the process of differentially processing the scattered light signals of particles entering different voltage comparators, multiple amplifier circuits are used, each amplifier circuit using a different preset magnification factor for amplification, and each amplifier circuit is connected to a corresponding voltage comparator and a counter. It should be noted that, as an embodiment, the structure of each amplifier circuit is the same. To achieve different magnification factors, certain components, such as resistors, can use different resistance values. As an embodiment, the structure of each voltage comparator is also the same, except that the threshold values ​​set for comparison can be the same or different. Although the particle size standards preset for counting by each comparator are different, the threshold setting is preferably not significantly different, usually within 10 times, or even within 3 times or 2 times. The counter can count based on the comparison results of each comparator by a single-chip microcomputer, or by a counting circuit, which is not limited here. The voltage pulse signal output by the preamplifier circuit is amplified by different factors in multiple amplifier circuits with different preset magnification factors to form a particle signal. The particle signal is compared with the threshold value of each voltage comparator, and counting is performed based on the comparison results of the particle signal and each threshold value. Since each amplifier circuit, voltage comparator, and counter corresponds to each other, each set of amplifier circuits, voltage comparators, and counters can be referred to as a set of amplifier, comparison, and counting circuits. It should be clarified that each set of amplifier, comparison, and counting circuits counts particles that are within a predetermined particle size standard or larger.

[0043] It should be noted that the preset magnification of the amplification circuit in each set of amplification, comparison and counting circuits is determined based on the size of the preset particle size standard preset by the voltage comparator, and the preset magnification is negatively correlated with the particle size. There is no limitation on the specific value of the preset magnification. In practice, when the amplification circuit is required to identify large-sized particles, the preset magnification can be set to a number greater than 1, equal to 1, no amplification, or even less than 1, without limitation; when the amplification circuit is required to identify small-sized particles, the preset magnification should be set to a number greater than 1. It can be understood that the function of the amplification circuit is mainly to amplify small-sized particles. In one embodiment, a particle counter is used to identify and count particles of 0.1 μm and above, and has 6 voltage comparators for preset passed particle size standards including 0.1 μm, 0.3 μm, 0.5 μm, 1 μm, 5 μm, and 10 μm. The amplifier circuit corresponding to each voltage comparator has preset magnification factors of 50, 30, and 10 for 0.1 μm, 0.3 μm, and 0.5 μm less than 1 μm, respectively, and the preset magnification factor of 10 μm among 1 μm, 5 μm, and 10 μm above 1 μm is 0.8. The preset particle size standard and preset factor can be adjusted according to actual needs, and no specific limitation is made here. The threshold value of each voltage comparator is calibrated by the voltage comparator according to the size of the preset passed particle size standard and the magnification factor corresponding to the amplifier circuit corresponding to the voltage comparator. Here, the preset magnification factor of the amplifier circuit corresponding to the voltage comparator is set based on the size of the preset particle size standard that the corresponding voltage comparator passes. Since the scattered light signals of particles of different particle sizes may have similar or even identical signal values ​​output by each group of amplification, comparison and counting circuits after amplification by the preamplifier circuit and the amplifier circuit, the threshold values ​​of each voltage comparator can be set to the same value or different values. This does not affect the particle counter's identification and counting of particles of different particle size standards, and the specific value of the threshold value is not limited. In addition, the threshold value is limited by the maximum voltage value that can be set for the threshold value used for comparison in the voltage comparator itself. In implementation, the voltage comparator can use an op amp to compare the received particle signal with the threshold value. For example, if the particle signal is greater than the threshold value, it outputs 1 and the corresponding counter counts; otherwise, it outputs 0 and does not count. This is not a specific limitation. It is worth noting that each voltage comparator is used to identify particles of a preset particle size standard. When the particle size corresponding to the particle signal received by the voltage comparator is greater than or equal to the preset particle size standard, the corresponding counter counts. Figure 2 This is a schematic diagram of a particle scattered light signal amplification and counting circuit for counting provided in an embodiment of the present application. Figure 2As shown, the scattered light signal is converted into a photocurrent signal by the photodetector 1; the photocurrent signal is converted into a voltage pulse signal by the preamplifier circuit 2; the voltage pulse signal is formed into corresponding particle signals such as the first particle signal, the second particle signal, ..., the nth particle signal after passing through each amplifier circuit 3, and each particle signal is compared with the threshold value of the corresponding voltage comparator 4, such as the first particle signal is compared with the first threshold value, the second particle signal is compared with the second threshold value, ..., the nth particle signal is compared with the nth threshold value; according to the comparison result, the corresponding counter 5 is used to count, such as obtaining the first counting result, the second counting result, ..., the nth counting result. Each group of amplification, comparison and counting circuits is for counting particles with a particle size standard and a size above the particle size standard. Assume Figure 2 In the figure, the first particle signal, the first threshold value, and the first counting result are the particle counts at the 0.1 μm level in the corresponding amplifying and comparing counting circuit (here, the 0.1 μm level means that particles of 0.1 μm and above can be identified); the second particle signal, the second threshold value, and the second counting result are the particle counts at the 0.3 μm level in the corresponding amplifying and comparing counting circuit (here, the 0.3 μm level means that particles of 0.3 μm and above can be identified)…, the nth particle signal, the nth threshold value, and the nth counting result are the particle counts at the 10 μm level in the corresponding amplifying and comparing counting circuit (here, the 10 μm level means that particles of 10 μm and above can be identified), and so on. Usually, in order to facilitate signal identification (the scattered light signal of the particle is positively correlated with the particle size), each amplifier circuit is set to a different amplification factor (the particle will enter all the amplification voltage comparators). The smaller the particle size that can be counted, the greater the amplification factor. For example, the amplification factor of the circuit at the 0.3μm level may be 20 times, the amplification factor of the circuit at the 0.5μm level may be 3 times, the amplification factor of the circuit at the 5μm level may be 1 times (no amplification), the amplification factor of the circuit at the 10μm level may be 0.9 times, and so on. Generally, the factor required to identify small-sized particles will be amplified, while the factor for the large particle identification channel may be amplified, unchanged, or even reduced.

[0044] The particle scattered light signal amplification and counting circuit provided in this embodiment includes: a preamplifier circuit connected to the output end of a photodetector in a particle counter, multiple voltage comparators, and multiple counters, and also includes: multiple amplification circuits; the amplification circuits, voltage comparators, and counters correspond to each other one by one; the photodetector is used to receive scattered light signals and convert the scattered light signals into photocurrent signals; the preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit, and is used to amplify the received photocurrent signal after conversion by the transimpedance amplifier and then amplified by the first signal amplification circuit to obtain a voltage pulse signal; the input end of each amplification circuit is respectively connected to the output end of the preamplifier circuit; the circuit is used to amplify the voltage pulse signal according to a preset multiple to form a corresponding particle signal; wherein each amplification circuit corresponds to a different preset multiple; the input end of each voltage comparator is respectively connected to the output end of the corresponding amplification circuit; the circuit is used to compare the particle signal with a threshold value in the voltage comparator and output a comparison result; the input end of each counter is respectively connected to the output end of the corresponding voltage comparator; the circuit is used to count according to the comparison result. In this circuit, the corresponding particle signal is amplified by different multiples through the amplifier circuit. For example, particles with large particle sizes can be amplified at a smaller multiple, and particles with small particle sizes can be amplified at a larger multiple. In other words, the particle signal is processed differentially, so that the requirement for the maximum output voltage of the amplifier circuit is reduced and the energy consumption of the device is reduced, thereby minimizing the occurrence of a situation where the accuracy of the particle counter is reduced due to the heating environment caused by the high energy consumption of the device, thereby improving the accuracy of the particle counter.

[0045] In practice, a reasonable threshold value needs to be set for each voltage comparator. A preferred implementation method is that the threshold value in each voltage comparator is preset based on the preset multiple of the corresponding amplifier circuit combined with the preset particle size standard that the voltage comparator passes. By calibrating each standard particle size and the magnification corresponding to each standard particle size, the basis for setting the threshold value in each voltage comparator is obtained. Since the threshold value of each voltage comparator is obtained based on the calibration of particles of each particle size and the corresponding magnification, the set threshold value is relatively reasonable. The particle counter usually counts particles of multiple different particle size standards. Usually, the threshold value used for comparison in the voltage comparator is smaller than the particle signal of the preset particle size standard that is preset in the corresponding amplifier circuit, but is larger than the particle signal output in the amplifier circuit of particles of other particle size standards that are smaller than the particle size standard among multiple different particle size standards. For example, 0.1μm, 0.3μm, 0.5μm, 1μm, 5μm, 10μm; a comparator is used to count particles of 0.5μm and above, then the threshold used in the comparator for comparison with the particle signal is smaller than the particle signal of 0.5μm particles outputted from the corresponding amplifier circuit, and is larger than the particle signal of 0.3μm particles outputted from the corresponding amplifier circuit.

[0046] Based on the above embodiment, the particle scattered light amplification and counting circuit may be subject to interference such as noise, resulting in reduced particle identification accuracy. Therefore, in a preferred embodiment, the particle scattered light amplification and counting circuit further includes a filter provided on the amplification circuit to filter out noise outside the particle signal and obtain a filtered particle signal.

[0047] In practice, multiple filters can be provided; the amplifier circuit, voltage comparator, counter, and filter correspond one to one. There is no limitation on the filters used, such as RC filter circuits, capacitors, etc. In this embodiment, the filters correspond one to one with the amplifier circuit, voltage comparator, and counter, that is, a filter is connected before each amplifier voltage comparator to filter out noise signals, etc. In practice, however, since noise signals are more likely to be close to the signals of small-size particles, it is also possible to set a filter only for the channel where the small-size standard is located.

[0048] The particle scattered light amplification and counting circuit provided in this embodiment further includes a filter provided on the amplification circuit, which can minimize the interference of noise signals on particle signals, thereby making the obtained particle count more accurate.

[0049] Likewise, one or more filters may be provided on the first signal amplifying circuit.

[0050] In practice, if an amplifier circuit is used to directly amplify the voltage pulse signal by a larger multiple, since the larger the amplification multiple, the greater the noise that may be introduced, the preferred implementation method is that the amplifier circuit is used to amplify and filter the voltage pulse signal output by the preamplifier circuit in order to obtain an accurate particle signal.

[0051] The embodiment provides a method for amplifying the voltage pulse signal once or multiple times through an amplifier circuit. During each amplification process, the amplification and filtering can be performed simultaneously, which can reduce noise generation in the entire circuit and thus make particle counting more accurate.

[0052] When particles of different sizes are amplified according to different preset magnifications, it is necessary to amplify the particles of different sizes according to reasonable preset magnifications. In practice, it is preferred that the preset magnification is negatively correlated with the size of the particle size.

[0053] The preset magnification is negatively correlated with the particle size. A larger magnification is set for small particles, and a smaller magnification is set for large particles. In other words, small particles need to be magnified, while large particles may be magnified at a smaller magnification, not magnified, or even reduced.

[0054] The preset magnification provided in this embodiment is negatively correlated with the particle size. Since large particles are already sufficiently identified by the preamplifier circuit, there is no need to amplify them by a large magnification (i.e., greater than 1). Amplification may increase the maximum output voltage requirement of the amplifier circuit. Conversely, when a small magnification factor is set (i.e., less than 1), the maximum output voltage requirement of the amplifier circuit is reduced, thereby reducing energy consumption of the device. Amplifying small particles by a large magnification factor can ensure that small particles are identified as much as possible, thereby achieving more accurate particle counting.

[0055] Based on the above embodiment, this embodiment further provides a particle counter including the above particle scattered light signal amplifying and counting circuit, which has the same beneficial effects as the particle scattered light signal amplifying and counting circuit described in the above embodiment and will not be described in detail here.

[0056] Based on the above embodiment, this embodiment further provides a method for amplifying and counting particle scattered light signals, which is applied to a particle scattered light signal amplifying and counting circuit including a preamplifier circuit, multiple amplifier circuits, multiple voltage comparators, and multiple counters. The amplifier circuits, voltage comparators, and counters correspond to each other one by one. The preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit; the input end of each amplifier circuit is respectively connected to the output end of the preamplifier circuit; the input end of each voltage comparator is respectively connected to the output end of the corresponding amplifier circuit; and the input end of each counter is respectively connected to the output end of the corresponding voltage comparator.

[0057] Figure 3 A flowchart of a method for amplifying and counting particle scattered light signals provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the method includes:

[0058] S10: converting the scattered light signal into a photocurrent signal through a photodetector;

[0059] S11: converting the received photocurrent signal through a transimpedance amplifier via a preamplifier circuit, and then amplifying it through a first signal amplification circuit to obtain a voltage pulse signal;

[0060] S12: amplifying the voltage pulse signal by a preset multiple through each amplifier circuit to form a corresponding particle signal; wherein each amplifier circuit corresponds to a different preset multiple;

[0061] S13: Comparing the particle signal with a threshold value in the voltage comparator through each voltage comparator;

[0062] S14: Obtain the comparison results of the voltage comparators through each counter, and count according to the comparison results.

[0063] The present embodiment provides a method for amplifying and counting particle scattered light signals, which converts scattered light signals into photocurrent signals through a photodetector; converts the received photocurrent signals through a transimpedance amplifier through a preamplifier circuit, and then amplifies them through a first signal amplification circuit to obtain a voltage pulse signal; amplifies the voltage pulse signals by a preset multiple by each amplification circuit to form a corresponding particle signal; wherein each amplification circuit corresponds to a different preset multiple; compares the particle signal with a threshold value in the voltage comparator through each voltage comparator; obtains the comparison result of the voltage comparator through each counter, and counts according to the comparison result. In this method, the corresponding particle signal is amplified by different multiples by the amplification circuit, such as a smaller multiple for particles with a larger particle size and a larger multiple for particles with a smaller particle size, that is, the particle signal is differentially processed, thereby reducing the requirement for the maximum output voltage of the amplification circuit and reducing the energy consumption of the device, thereby minimizing the occurrence of a situation where the accuracy of the particle counter is reduced due to the heating environment caused by the high energy consumption of the device, thereby improving the accuracy of the particle counter.

[0064] In order to enable those skilled in the art to better understand the technical solution of this application, Figure 4 Further details of the above application are given below. Figure 4 This is an overall flow chart of a method for amplifying and counting particle scattered light signals provided in an embodiment of the present application. Figure 4 As shown, the process includes:

[0065] S15: Acquire particle scattered light;

[0066] S16: Acquire a first voltage pulse signal corresponding to the particle scattered light signal;

[0067] S17: amplifying the first voltage pulse signal once or multiple times by the same multiple to form a second voltage pulse signal;

[0068] S18: amplifying the second voltage pulse signal by different multiples in a plurality of unconnected circuits to form a particle signal;

[0069] S19: comparing the particle signal with each threshold value;

[0070] S20: Counting is performed according to the comparison results between the particle signal and each threshold value.

[0071] The method for amplifying and counting particle scattered light signals provided in this embodiment performs differentiated processing on particle signals entering different amplifying circuits, thereby reducing the requirement for the maximum output voltage of the amplifying circuits and the energy consumption of the equipment. This minimizes the occurrence of a situation in which the accuracy of the particle counter is reduced due to the heat environment caused by the high energy consumption of the equipment, thereby improving the accuracy of the particle counter.

[0072] The above is a detailed introduction to the particle scattered light signal amplification and counting circuit, method, and particle counter provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in detail. It should be noted that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the scope of protection of the claims of this application.

[0073] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A particle scattered light signal amplification and counting circuit, comprising: A preamplifier circuit, multiple voltage comparators, and multiple counters connected to the output end of a photodetector in a particle counter, wherein the photodetector is used to receive scattered light signals and convert the scattered light signals into photocurrent signals; The preamplifier circuit includes a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit, and is configured to convert and amplify the received photocurrent signal by the transimpedance amplifier and then amplify the signal by the first signal amplification circuit to obtain a voltage pulse signal; It is characterized by further comprising: a plurality of amplifying circuits; the amplifying circuits, the voltage comparators, and the counters correspond to each other in a one-to-one manner; The input end of each amplifier circuit is respectively connected to the output end of the preamplifier circuit; and is used to amplify the voltage pulse signal by a preset multiple to form a corresponding particle signal; wherein each amplifier circuit corresponds to a different preset multiple; and the preset multiple is negatively correlated with the particle size; The input end of each voltage comparator is connected to the output end of the corresponding amplifier circuit respectively; and is used to compare the particle signal with the threshold value in the voltage comparator and output a comparison result; The input end of each counter is connected to the output end of the corresponding voltage comparator respectively; and is used to count according to the comparison result; Wherein, the threshold value in each of the voltage comparators is preset according to the preset multiple of the corresponding amplification circuit combined with the preset particle size standard that the voltage comparator passes; The voltage comparator outputs a counting signal for particles that have passed a preset particle size standard or above.

2. The particle scattered light signal amplifying and counting circuit according to claim 1, characterized in that: Also includes: The filter provided on the amplifying circuit is used to filter the noise outside the particle signal and obtain the filtered particle signal.

3. The particle scattered light signal amplifying counter according to claim 1, characterized in that: The first signal amplifying circuit is used to amplify the photocurrent signal after it is converted and amplified by the transimpedance amplifier multiple times to obtain the amplified voltage pulse signal.

4. A particle counter, characterized in that The invention comprises the particle scattered light signal amplifying and counting circuit according to any one of claims 1 to 3.

5. A method for amplifying and counting particle scattered light signals, characterized in that: A particle scattered light signal amplification and counting circuit is applied to a particle scattered light signal amplification and counting circuit comprising a preamplifier circuit, multiple amplification circuits, multiple voltage comparators, and multiple counters, wherein the amplification circuits, the voltage comparators, and the counters correspond to each other one by one, the preamplifier circuit comprising a transimpedance amplifier and a first signal amplification circuit for amplifying the received signal in the same circuit; the input end of each amplification circuit is respectively connected to the output end of the preamplifier circuit; the input end of each voltage comparator is respectively connected to the output end of the corresponding amplification circuit; The input end of each counter is respectively connected to the output end of the corresponding voltage comparator; the method includes: Converting the scattered light signal into a photocurrent signal by the photodetector; The received photocurrent signal is converted and amplified by the preamplifier circuit through the transimpedance amplifier, and then amplified by the first signal amplification circuit to obtain a voltage pulse signal; The voltage pulse signal is amplified by each amplifier circuit according to a preset multiple to form a corresponding particle signal; wherein each amplifier circuit corresponds to a different preset multiple; and the preset multiple is negatively correlated with the particle size; Comparing the particle signal with a threshold value in the voltage comparator through each of the voltage comparators; Obtaining comparison results of the voltage comparators through each of the counters, and counting according to the comparison results; Wherein, the threshold value in each of the voltage comparators is preset according to the preset multiple of the corresponding amplification circuit combined with the preset particle size standard that the voltage comparator passes; The voltage comparator outputs a counting signal for particles that have passed a preset particle size standard or above.

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