RU2362144C1 - Device to determine characteristics of gas and fluid samples - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to instrument making and can be sued, for example in biochemical analysis instrumentation. The proposed device incorporates the casing, mount assembly to accommodate the sample pan tray, read-off assembly and two jog drives mounted on aforesaid casing. One of the latter rotates the said mount about its vertical axis, the other one rotates the said read-off assembly about vertical axis located on one edge of the said assembly so that, in rotation, optical axes of the photo receiver and radiator, located on the opposite side of read-off assembly passes through all sample pans of rotating tray.

EFFECT: smaller sizes, simpler design achieved due to rotary motion, not linear.

8 dwg

Description

The present invention relates to instrumentation and can be used to measure the optical density of liquid solutions, including biological materials, as well as in meteorology to determine the moisture content of clouds and fogs.

A device for determining the characteristics of gas and liquid samples [Pat. 4580895 United States, IPC ⁴ G01N 33/48. Sample-Scanning Photometer [Text] / Shailen S. Patel .; assignee Dynatech Laboratories, Incorporated - No. 546451; Filed oct. 28, 1983; Date of Patent Apr.8, 1986], comprising a housing, an installation unit for placing a sample tablet, two step drives for moving the installation unit along two mutually perpendicular axes, a stationary readout unit containing an emitter and a photodetector with a filter placed on opposite sides of the plane of movement of the installation site with the tablet. The device also contains processing units, registration and management.

The disadvantages of the analogue are its significant dimensions and complex configuration, due to the use of the node coordinate the movement of the tablet with samples. The ability to move the tablet along two axes requires the device to have a free area equal to at least the area of four tablets. The mobility of the second stepper motor (moved with the tablet during the operation of the first stepper drive) requires a complex electrical wiring system. Also complex is the tablet centering system. The disadvantages include the difficulty of replacing the filter, which is located in the lower part of the housing.

Of the analogues, the closest in technical essence to the proposed device is [Pat. 2035716 Russian Federation, IPC ⁶ G01N 21/01, 21/13, 21/25, 21/59, 33/48. A device for determining the characteristics of gas and liquid samples [Text] / Mashkovtsev A.P., Osipov L.S., Pilipenko K.N .; Applicants and patent holders Mashkovtsev A.N., Osipov L.S., Pilipenko K.N. - No. 92001686/25; declared 10.21.92; publ. 05/20/95, bull. Number 14. - 5 p.: Ill.], Which is selected as a prototype. In the prototype, compared to the analogue, the dimensions are reduced, the design is simplified, and the accuracy and ease of use are improved.

The technical result in the prototype is achieved by the fact that, in contrast to the analogue, the mounting unit is moved with only one step drive along one coordinate axis, and the reading unit is movable and in the process of moving is moved by the second step drive along an axis perpendicular to the axis of movement of the installation node, moreover, the second step drive, like the first, is rigidly mounted on the housing. Due to this, the required working area is reduced and the design is simplified.

In addition, the installation node in the prototype is equipped with a spring-loaded latch, which is made with the possibility of clamping the tablet when moving the installation node relative to the external stop. Thus, the prototype provides uniqueness and automatic fixation of the tablet, which increases the accuracy of measurements and ease of use compared to the analogue.

Improving the usability is achieved in the prototype also by the fact that, in contrast to the analogue, the emitter and the photodetector are located respectively below and above the plane of movement of the installation site, and the filter is removable.

Figure 1 presents the functional diagram of the device of the prototype in the initial state, figure 2 is a functional diagram of the reading node. Figure 3 shows a functional diagram explaining the relative position of the installation and reading nodes of the prototype in the process of scanning the tablet.

The prototype (figure 1, 2) contains a housing 1, a mounting unit 2 for placing a tablet 3 with cuvettes for the test samples, equipped with a spring-loaded clamp 4, which is made to clamp the tablet 3 when moving the mounting unit 2 relative to the external stop 5, the reading unit 6 made with photodetector 7 and emitter 8 located on opposite sides of the plane of movement of the tablet 3 and emitter 8, located on the bottom side of the cell and connected to a power source 9, two step drives 10 and 11, rigidly mounted on the housing 1, and are removable the th filter 12, located in front of the photodetector 7, connected to the corresponding input of the processing, recording and control units 13, 14, 15, and the drives 10 and 11 are connected to the output. The first drive 10 is arranged to move the mounting unit 2 along the first axis, the second drive 11 is arranged to rotate the reading unit 2 along the second axis perpendicular to the first, and the external stop 5 is located on the housing 1 with the possibility of acting on the latch 5 when moving the mounting unit 2 relative to the housing 1.

The reading unit 6 (Fig. 2) is a U-shaped structure, in the upper part of which there is a photodetector 7 with a removable light filter 12, and in the lower part there is an emitter 8 so that the mounting unit 2 with the tablet 3 has the ability to move between them ( 1 and 3 show only the upper part of the U-shaped structure). The placement of the removable filter 12 in the upper part of the U-shaped design provides convenient operator access to it.

The prototype works as follows.

Let in the initial state the reading unit 6 through its stepper drive 11 is installed in the extreme position opposite the row "1" of the cuvette of the tablet 3 (see figure 1). The installation unit 2 through its stepper drive 10 is moved to the loading position, that is, it is located outside the reading unit 6, which does not interfere with the installation (or removal) of the tablet 3. In this position, the installation unit 2 is located close to the housing 1, and the stop 5, acting on the spring-loaded shoulder of the latch 4, squeezes it, allowing you to install (or remove) the tablet 3. Thus, in the initial state of the device, the tablet 3 is available for removal and installation. A removable light filter 12 is installed in the reading unit 6, corresponding to the applied research method.

Getting started, the operator places the next tablet 3 in the installation node 2, selects one of the programs available in the device and starts the measurement. All other operations are carried out by the prototype automatically.

The mounting unit 2 with the tablet 3 is moved by the corresponding step drive 10 along the first axis, that is, along the direction (AH) of the cuvette of the tablet 3. At the same time, the latch 4 comes out of contact with the stop 5 and clamps the tablet 3. When combining the optical axis of the readout unit 6 with each next cell of the first row, in which the test sample is located, the emitter 8 is turned on and measurement is performed (by the principle of vertical photometry). After scanning the first row (A1-H1) of the cuvette, the reading unit 6 is moved by the corresponding step drive 11 along the second axis perpendicular to the first, that is, along the direction (1-12) of the cuvette of the tablet 3, to the next row. Next, the installation unit 2 again moves and the row of “2” cuvettes of the tablet 3 is scanned. This process is repeated until the scanning of all the cuvettes of the tablet 3 is completed, and the centers of the cuvettes move along 12 parallel straight lines, respectively, “1” - “12”, and the optical axis of the reading unit 6 moves in a perpendicular direction intersecting these straight lines, respectively, the rows of the cell cuvette “A” - “H”. Figure 3 shows the position of the installation and reading nodes when measuring cell B9.

Upon completion of the scan of the tablet 3, the reading unit 6 through its step drive 11 returns to its original position, that is, opposite the row “1” of the tablet cuvette, and the installation unit 2 through its step drive 10, moving towards the housing 1, returns to the loading position. The stop 5, acting on the latch 4, squeezes it, the tablet 3 is released, it can be removed and replaced by the following. In this case, the processing, registration and control units 13, 14, 15 provide processing and registration of the received primary measurement information.

The real design parameters of the prototype nodes are selected so that scanning is carried out by a beam with a diameter of 1 mm with a step of 0.04 mm. This feature of the prototype further expands the scope of its application, and allows its use not only when scanning tablets, but, in particular, with continuous scanning of film samples (furograms).

The prototype allows you to measure solutions in the cuvette tablets, in the following modes of operation: measurement of optical density relative to air or blank sample; determination of the concentration of the analytes according to previously known coefficients; determination of the concentration of analytes using standard samples; measurement of optical density before and after a chemical reaction, followed by conversion to concentration units according to known coefficients or using standards.

From the presented description it can be seen that the prototype performs all the necessary measurements of the tablet 3 using two single-axis stepper drives 10 and 11, stationary relative to the housing, which does not require complex electrical wiring. In this case, the dimensions of the prototype device are estimated by the size of the working area S _CR covered by the tablet 3 when it is moved during the scanning process. The desired rating is determined in the prototype by the dimensions of the double area of the tablet, namely:

S _ol = 2ab,

where a and b are respectively the length and width of the tablet (overall dimensions).

That is, the two-coordinate system of interdependent linear movement of the installation and reading nodes along mutually perpendicular axes parallel to the plane of the tablet, implemented in the prototype, allows not only to simplify the system of connecting step drives (due to the fixed installation of both drives), but also to halve, compared to the analogue The area used to move the tablet.

At the same time, it should be noted that the prototype does not reach the maximum minimum size, which, naturally, is limited by the size of the tablet itself. Therefore, there is the potential for further reduction in size, which is not implemented by the technical solution of the prototype. In addition, as is well known, the design of the mechanisms of precise linear movement used in the prototype contains several kinematic pairs, therefore it has a rather complicated practical implementation (see, for example, [Kolpakov A.P. Design and calculation of mechanical gears / A.P. Kolpakov, I.E. Karnaukhov. - M .: Kolos, 2000. - 328 p., Ill .; S.204], [Panov V.A. Handbook of the designer of optical-mechanical devices / V.A. Panov [et al. .]; under the general editorship of V.A. Panov. - 3rd ed., revised and supplemented. - L.: Mechanical Engineering, Leningrad Department, 1980. - 742 p., ill .; S. 436-442], [Erdedi A.A. Det whether there are machines: Textbook for mechanical engineering special secondary professional educational institutions / A.A. Erdedi, N.A. Erdedi. - 2nd ed., rev. and additional.- M .: Higher school. ; Publishing Center "Academy", 2001. - 285 p., S.216]).

The disadvantages of the prototype are the large size and complexity of the design, determined by the selected method of scanning the tablet based on the linear movement of the installation and read nodes along mutually perpendicular axes.

The problem to which the invention is directed, is to create a device that performs the measurement of solutions in the cuvettes of the tablet with less than the prototype, the size of the working area covered by the tablet during its movement during scanning, and a simpler kinematic scheme.

The technical result is to reduce the size of the device and simplify its design.

To achieve the specified technical result in a device containing a housing, an installation unit for placing a tablet with cuvettes for the test samples, equipped with a spring-loaded clamp, which is capable of clamping the tablet when moving the installation unit relative to the external stop, a reading unit made with placed on opposite sides of the plane of movement of the tablet with a photodetector and emitter located on the bottom of the cell and connected to a power source, two step drives, rigidly mounted on the housing, a removable filter located in front of the photodetector connected to the corresponding input of the processing, registration and control units, and the drives are connected to the output, the first drive is made to rotate the mounting unit around its own vertical axis, and the second drive is made to rotate the reading unit around a vertical axis located on one edge of this node so that during rotation the optical axis of the photodetector and emitter located on the other edge of the reading node and rotating through all of the cell plate, wherein the external abutment located on the reader unit to act on the latch during rotation and positioning of the reading units.

The essence of the invention consists in creating a compact and simple device for determining the characteristics of gas and liquid samples by changing the kinematic scheme of the drives of the installation and reading units by replacing the linear movement by rotational and reducing, due to this, the required area for the implementation of the scanning process.

The essence of the invention is illustrated by drawings, where Fig. 4 is a functional diagram of a device in its initial state, Fig. 5 is a functional diagram of a reading unit, Fig. 6 is a functional diagram of a device during scanning of a tablet, and Fig. 7 shows the trajectories of the centers of cuvettes and the path of the optical axis of the reading unit during the scanning process of the tablet, Fig. 8 presents a simplified drawing of a standard 96-well tablet manufactured by the All-Russian Research Institute of Medpolymer, Moscow (TU 64-05-1871).

The proposed device (Figs. 4, 5) comprises a housing 1, an installation unit 2 for accommodating a tablet 3 with cuvettes for the test samples, equipped with a spring-loaded latch 4, which is capable of clamping the tablet 3 when moving the installation unit 2 relative to the external stop 5, a reading unit 6, made with photodetector 7 and emitter 8 located on opposite sides of the tablet’s plane of movement, located on the bottom of the cuvette and connected to a power source 9, two step drives 10 and 11, rigidly mounted on the core Puse 1, a removable filter 12, located in front of the photodetector 7, connected to the corresponding input of the processing, registration and control units 13, 14, 15, and the drives 10 and 11 are connected to the output. In this case, the first drive 10 is arranged to rotate the mounting unit 2 around own vertical axis, and the second drive 11 is configured to rotate the reading unit 6 around a vertical axis located on one edge of this unit 6 so that when rotating the optical axis of the photodetector 7 and emitter 8 located on the other edge of the reading its node 6, passed through all the cuvettes of the rotating tablet 3, and the external stop 5 is located on the reading node 6 with the possibility of impact on the latch 4 during rotation of the installation 2 and read 6 nodes.

The reading unit 6 (Fig. 5) is a U-shaped design, in the upper part of which there is a photodetector 7 with a removable light filter 12, and in the lower part there is an emitter 8 so that the mounting unit 2 with the tablet 3 has the ability to move between them ( Figures 4 and 6 show only the upper part of the U-shaped structure). The placement of the removable filter 12 in the upper part of the U-shaped design provides convenient operator access to it.

The device operates as follows.

Let in the initial state, the installation node 2, associated with the step drive 10, is in the boot position. The reading unit 6, connected with the stepper drive 11, is in the position of maximum distance from the axis of rotation of the mounting unit 2, i.e. turns out to be outside the installation unit 2 and does not interfere with the installation (or removal) of the tablet 3. With this mutual position of the installation 2 and reading 6 nodes, the stop 5 located on the reading node 6 acts on the spring-loaded shoulder of the latch 4 and squeezes it, allowing you to install (or remove ) tablet 3. Thus, in the initial state of the device, tablet 3 is available for removal and installation. A removable light filter 7 is installed in the reading unit 6, corresponding to the applied research method.

Getting started, the operator places the next tablet 3 in the installation node 2, selects one of the programs available in the device and starts the measurement. The device carries out all other operations automatically.

After starting the measurement, the stepper drive 11 rotates the reading unit 6 around the vertical axis of rotation located on the edge of this unit 6 towards the mounting unit 2. At the same time, the latch 4 comes out of contact with the stop 5 and clamps the tablet 3. The reading unit 6 is rotated before being installed in position I (Fig.7), in which its optical axis is aligned with the trajectory of the centers of the cells A1, A12, H1, H12. The step drive 10 rotates the mounting unit 2 with the tablet 3, for example, in the direction indicated by the arrows in FIG. 4. When combining the optical axis of the readout unit 6 with the center of the nearest cuvette - A12 of tablet 3 (Fig. 4), in which the test sample is located, the emitter 8 is turned on and measurement is performed (by the principle of vertical photometry).

Continued rotation of the mounting unit 2 leads to the alignment of the optical axis of the reading unit 6 with the center of the next cuvette -H12 located on the same circle I. In this case, the emitter 8 is turned on again and measurement is performed.

In the process of further rotation of the mounting unit 6, the optical axis of the reading unit 6 is sequentially aligned with the centers of two other cuvettes of the circle I - H1, A1, and each time the emitter 8 is turned on and measurement is performed.

After scanning all the cuvettes of circle I, the step drive 11 rotates the reading unit 6 to position II, that is, until its optical axis is aligned with the trajectory of the centers of cuvettes B12, G12, G1, B1 lying on circle II (Fig. 7). Then again, the step drive 10 rotates the mounting unit 2, and now the scanning of the cuvette of the circle II, the centers of which are sequentially aligned with the optical axis of the reading unit 6, is already being performed, and each time the emitter 8 is turned on and the measurement is performed.

Upon completion of the scan of all cuvettes of circle II, the reading unit 6 is installed in position III (Fig. 7), after which the mounting unit 2 performs the next — third — revolution, during which the centers of the cuvettes A11, C12, F12, H11, H2, F1, C1 , A2 are sequentially aligned with the optical axis of the reading unit 6, and each time when aligned, the emitter 8 is turned on and a measurement is performed.

Next, the process is repeated until the scanning of all the cuvettes of the tablet 3 is completed, and the 6-reading unit is alternately installed in positions IV to XVI (Fig. 7), that is, its optical axis is alternately aligned with the paths of the cuvettes, the centers of which are located in groups IV - XVI, namely:

group IV - cuvettes D1, D12, E1, E12;

group V - cuvettes B2, B11, G2, G11;

group VI - cuvettes A3, A10, H3, H10;

group VII - cuvettes C2, C11, F2, F11;

group VIII - cuvettes D2, D11, E2, E11;

group IX - cells A4, A9, B3, B10, G3, G10, H4, H9;

group X - cuvettes A5, A8, C3, C10, F3, F10, H5, H8;

group XI - cuvettes A6, A7, B4, B9, D3, D10, E3, E10, G4, G9, H6, H7;

group XII - cuvettes B5, B8, C4, C9, F4, F9, G5, G8;

group XIII - cuvettes B6, B7, D4, D9, E4, E9, G6, G7;

group XIV - cuvettes C5, C8, F5, F8;

group XV - cuvettes C6, C7, D5, D8, E5, E8, F6, F7;

group XVI - cuvettes D6, D7, E6, E7.

In this case, the mounting unit 2, rotating, provides, for its part, the alternate alignment of the centers of the cuvettes of each group with the optical axis of the reading unit 6. Figure 6 shows the position of the mounting 2 and reading 6 nodes when measuring the cuvette F5.

At the end of the scan of the tablet 3, the installation unit 2 and the reading unit 6 return to the initial state shown in Fig. 4, that is, they come to a position in which the reading unit 6 is outside the installation unit 2, and the stop 5, acting on the spring-loaded latch 4 , wring it out. Tablet 3 is released, it can be removed and replaced with the following. In this case, the processing, registration and control units 13, 14, 15 provide processing and registration of the received primary measurement information.

The actual structural parameters of the nodes of the proposed device are selected so that the scan is carried out by a beam with a diameter of 1 mm in increments of 0.04 mm. This further expands the scope of the device and allows its use not only when scanning tablets, but also, in particular, with continuous scanning of film samples (furograms).

The proposed device allows the measurement of solutions located in the cuvette tablets, in the following modes of operation: measurement of optical density relative to air or blank sample; determination of the concentration of the analytes according to previously known coefficients; determination of the concentration of analytes using standard samples; measurement of optical density before and after a chemical reaction, followed by conversion to concentration units according to known coefficients or using standards.

Measurements in the inventive device when determining the characteristics of the studied liquid samples located in the cuvette of the tablets, are carried out at the intersection of the trajectories of the cuvette of the tablet 3 with the path of the optical axis of the reading node 6 during the mutual movement of the installation 2 and 6 reading nodes. At the same time, the centers of the cuvettes of the tablet 3 move along concentric circles of 16 radii, and the optical axis of the reading unit moves along an arc intersecting these circles (Fig. 7). Characterization of samples located on other media is carried out in exactly the same way, with the only difference being that the measurement according to the principle of vertical photometry is performed by combining the optical axis of the reading unit 6 with the necessary media points of the studied samples according to the design of each given type of media.

The device’s construction is based on the principle of transition to another dimension, namely, the principle of replacing the one-coordinate movement of positioning objects (cuvettes and reading unit) with their two-coordinate rotational movement, to perform measurements at the required points of the carrier of the samples under study, which reduces the size and simplifies the design of the device .

Let us evaluate the possible dimensions, taking as a basis for the assessment the value of the working area S covered by the tablet during its rotation during the scanning process. The desired estimate is determined by the diameter of the circle,

equal to the diagonal of the tablet

,

,

where a and b are respectively the length and width of the tablet (overall dimensions).

Comparing the values of the estimates of the working area for the proposed device S and the prototype S _p , we obtain a coefficient that quantitatively characterizes the achieved reduction in size in the proposed device compared to the prototype depending on the length and width of the tablet

Dividing the numerator and denominator of expression (1) by ab,

and denoting

,

,

get the characteristic of reducing the dimensions of the device depending on the ratio of the length and width of the tablet

The overall dimensions of a standard 96-well plate produced by the All-Russian Research Institute "Medpolymer" (Fig. 8) are:

along the length - a = 127 mm;

in width - b = 85 mm.

The sizes of tablets produced by other manufacturers, domestic or foreign, may differ only slightly. With this in mind, the ratio of the length and width of the tablet

Substituting this value in the formula (2), we obtain a quantitative characteristic of reducing the dimensions of the proposed device compared to the prototype using standard 96-well plates:

,

,

that is, the reduction in size of the proposed device, compared with the prototype, for standard 96-well plates is about 20%.

Since the scope of the proposed device, as well as the prototype, is not limited to only 96-well plates, we evaluate the size and conditions of the fundamentally possible maximum gain in size for any rectangular scan objects.

The first derivative of the function R (x)

vanishes at x = 1, and the second derivative of the function R (x)

when x = 1 has a negative value. Therefore, the function R (x) at x = 1 has a maximum, the value of which is

.

.

The obtained value of R _max quantitatively characterizes the maximum reduction in the dimensions of the proposed device compared to the prototype, which corresponds to a square object of scanning.

All blocks and elements of the claimed technical solution are well known. The receiving and radiating parts of the reading unit, processing, recording and control units, a power source can be performed similarly to the prototype. Stepper motors for drives of mounting and reading units do not have special requirements and can be typical of a wide range of commercially available domestic or foreign models, for example DSHI-200. Elements of gearing mechanisms (gears, belts and gears) can also be purchased commercially available, for example rows of gear kinematic pairs manufactured by Optibelt. It is also possible to use a stepper motor with a reducer combined in one commercially available product from a series manufactured, for example, by Fulling Motor.

Thus, the claimed device has all the functionality of the prototype, but with smaller dimensions and a simpler design.

Claims (1)

A device for determining the characteristics of gas and liquid samples, comprising a housing, an installation unit for placing a tablet with cuvettes for the samples under study, equipped with a spring-loaded clamp, which is capable of clamping the tablet when moving the installation unit relative to the external stop, a reading unit made with placed on opposite sides from the plane of movement of the tablet with a photodetector and emitter located on the bottom of the cell and connected to a power source, two step drives, rigidly mounted on the housing, a removable filter located in front of the photodetector connected to the corresponding input of the processing, recording and control units, and the drives are connected to the output, characterized in that the first drive is configured to rotate the mounting unit around its own vertical axis, and the second drive is made with the possibility of rotation of the reading node about a vertical axis located on one edge of this node so that when rotating the optical axis of the photodetector and emitter located on the other edge of the reading unit, passed through all the cuvettes of the rotating tablet, and the external stop is located on the reading unit with the possibility of acting on the latch during rotation of the installation and reading units.

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