Single-channel pipette calibration method

Abstract

The invention belongs to the technical field of pipettors, and particularly relates to a single-channel pipette calibration method which comprises the following specific steps: accurately calculating the precision of a pipette, and on this basis, formulating size machining precision standards of the diameter D of a piston rod, the screw pitch P of a limiting lead screw on a push rod, the position size L of a stop block and the height h of a pressing head of the piston rod; therefore, the weighing calibration is ensured to be consistent in a precision standard range. Secondly, controlling the diameter D of a piston rod, the screw pitch P of a limiting lead screw on a push rod, the position size L of a check block and the height h of a pressing head of the piston rod according to the precision standard of the machined parts in the first step, so that the parts have high interchangeability and assembly consistency, and it is guaranteed that weighing calibration has consistency. By manufacturing the tool clamp required by large-batch standardized production, the effect of low cost can be achieved, and the large-batch standardized production efficiency can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of pipettes, in particular to a single-channel pipette calibration method. Background Art

[0002] Pipettes are widely used in the field of life sciences, such as biology, pharmaceuticals, and diagnostics. Pipettes are divided into single-channel pipettes and multi-channel pipettes according to the number of nozzles for taking liquids. In recent years, with the rapid development of industries such as biology, medicine, and epidemic prevention, single-channel pipettes have been increasingly used.

[0003] Single-channel pipettes can accurately move liquid from one container to another, and are widely used in clinical diagnosis, biological testing, pharmaceutical research, chemical testing, environmental analysis, and food safety. Single-channel pipettes are precision measuring instruments that require precise weighing and calibration with precision weighing equipment before use. When mass-producing and calibrating, not only do you need to purchase a large number of expensive foreign precision weighing equipment, but you also need to strictly control the temperature and humidity of the environment before calibration, and train operators to strict standards before manual weighing and calibration. This leads to high cost and low efficiency of mass-producing calibration equipment. Therefore, a single-channel pipette calibration method is invented. Summary of the invention

[0004] In view of the above problems and / or the problems existing in an existing single-channel pipette calibration method, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a single-channel pipette calibration method that can solve the above-mentioned existing problems.

[0006] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0007] A single-channel pipette calibration method comprises the following specific steps:

[0008] Step 1: Calculate the accuracy of the pipette accurately, and based on this, formulate the processing accuracy standards for the piston rod diameter D, the upper limit screw pitch P of the push rod, the stopper position size L, and the piston rod pressing head height h, so as to ensure that the weighing calibration is consistent within the accuracy standard range;

[0009] Step 2: According to the precision standard of the parts processed in step 1, the piston rod diameter D, the upper limit screw pitch P of the push rod, the stopper position size L, and the piston rod pressing head height h are controlled to ensure that the parts are highly interchangeable and consistent in assembly, thereby ensuring consistency in weighing calibration;

[0010] Step 3: Make the fixtures required for standardized production, control the high consistency of parts assembly, and ensure the high consistency of weighing calibration;

[0011] Step 4: Since the liquid volume transferred by the single-channel pipette is related to the piston rod diameter D and the piston rod stroke H, that is: V = πD2 H / 4, therefore, when the piston rod diameter D is within the tolerance range of gb1800-79 js5, the liquid volume transferred by the single-channel pipette can be ensured to be within the standard range by controlling the piston rod stroke H. Therefore, an electronic height measurement mechanism can be made to control the piston rod stroke H; when the piston rod stroke H is within the tolerance of ±0.05, the liquid volume transferred by the single-channel pipette can be ensured to be within the standard range;

[0012] Step 5: Based on the electronic height measurement mechanism, a multi-dimensional calibration robot is manufactured. The multi-dimensional calibration robot is controlled by a computer connection to automatically grasp, measure, and calibrate large quantities of single-channel pipettes, so as to achieve high consistency in the mass production of single-channel pipettes and ensure that the mass production of single-channel pipettes is within the standard range, thereby solving the problem of high cost and low efficiency of mass production calibration equipment.

[0013] As a preferred solution of the single-channel pipette calibration method described in the present invention, the single-channel pipette includes a shell, a piston rod pressing head, a scale wheel knob, a push rod upper limit screw, a block, a push rod lower limit block, a piston rod push rod, a piston rod return spring, a piston rod sealing ring, a piston rod, a piston cylinder and a suction head. The bottom end of the shell is provided with a piston cylinder, and the piston rod is sealed in the piston cylinder by a piston rod sealing ring, so that when the piston rod moves, negative pressure or positive pressure is formed in the piston cylinder; the bottom end of the piston cylinder is provided with a suction head to absorb or squeeze out liquid through the suction head.

[0014] As a preferred solution of the single-channel pipette calibration method described in the present invention, a piston rod return spring is provided at the top of the piston rod, and the piston rod return spring is located in the middle of the shell, so that the top of the piston rod is always in contact with the bottom of the piston rod push rod.

[0015] As a preferred solution of the single-channel pipette calibration method described in the present invention, a stopper is provided on the piston rod push rod, and the piston rod push rod is slidably connected to the top of the shell, so that the piston rod push rod is pushed upward under the action of the piston rod return spring, and stops moving when the stopper hits the upper limit screw of the push rod.

[0016] As a preferred solution of a single-channel pipette calibration method described in the present invention, wherein: the piston rod push rod is fixed on the piston rod pressing head through the push rod upper limit screw rod and the push rod lower limit block, and the push rod upper limit screw rod and the push rod lower limit block are arranged on the top end of the shell, the piston rod pressing head is slidably connected to the top end of the shell, the distance that the block moves from the push rod upper limit screw rod to the push rod lower limit block is set as the piston rod stroke H, the top end of the shell is rotatably connected with a scale wheel knob, and the inner cavity of the scale wheel knob is slidably connected to the piston rod pressing head.

[0017] As a preferred solution of the single-channel pipette calibration method described in the present invention, wherein: the single-channel pipette is arranged in an electronic height measurement mechanism;

[0018] The electronic height measuring mechanism comprises an electronic height measuring instrument, a slide rail, a height measuring probe, a column and a pipette profiling positioning fixture, wherein a single-channel pipette is arranged in the pipette profiling positioning fixture, and a column is fixedly installed on the top left side of the pipette profiling positioning fixture.

[0019] As a preferred solution of the single-channel pipette calibration method described in the present invention, a slide rail is fixedly installed on one side of the column, an electronic height measuring instrument is fixedly installed on the slide rail, and a height measuring probe is provided on the electronic height measuring instrument so that the height measuring probe can contact the piston rod pressing head and measure the piston rod stroke H.

[0020] As a preferred solution of the single-channel pipette calibration method described in the present invention, a multi-dimensional calibration manipulator is provided on one side of the electronic height measurement mechanism to enable full-automatic grasping, measurement and calibration of the single-channel pipette.

[0021] Compared with existing technologies:

[0022] 1. By making the tooling and fixtures required for mass standardized production, not only will the cost-effectiveness be achieved, but also the efficiency of mass standardized production will be improved.

[0023] 2. By sampling, weighing and calibrating large quantities of products with high consistency, it is possible to achieve the goal of only requiring one expensive foreign precision weighing device, greatly reducing the cost of purchasing a large number of expensive foreign precision weighing devices.

[0024] 3. The semi-automatic or fully automatic calibration equipment produced will not only further reduce the cost investment, but also greatly improve the calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of the present invention;

[0026] Figure 2It is a front view schematic diagram of the structural state of the present invention;

[0027] Figure 3 It is a front view schematic diagram of the second structural state of the present invention;

[0028] Figure 4 It is a front view schematic diagram of the piston rod of the present invention;

[0029] Figure 5 It is a front view schematic diagram of the upper limit screw rod of the push rod of the present invention;

[0030] Figure 6 It is a front view schematic diagram of the piston rod push rod of the present invention;

[0031] Figure 7 It is a front view schematic diagram of the piston rod pressing head of the present invention;

[0032] Figure 8 It is a front view schematic diagram of the piston rod pressing head, the piston rod push rod and the pipette contour positioning fixture structure of the present invention;

[0033] Fig. 9 It is a front view schematic diagram of the structure of the single-channel pipette and the electronic height measurement mechanism of the present invention;

[0034] Fig.10 It is a front view schematic diagram of the overall structure of the present invention.

[0035] In the figure: piston rod pressing head 100, scale wheel knob 101, push rod upper limit screw 102, block 103, push rod lower limit block 104, piston rod push rod 105, piston rod return spring 106, piston rod sealing ring 107, piston rod 108, piston cylinder 109, suction head 110, electronic height measuring instrument 200, slide rail 201, height measuring probe 202, column 203, pipette contour positioning fixture 205, multi-dimensional calibration manipulator 300. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] The present invention provides a single-channel pipette calibration method, please refer to Figure 1-Figure 10 , including the following specific steps:

[0038] Step 1: Calculate the accuracy of the pipette accurately, and on this basis, formulate the processing accuracy standards for the piston rod 108 diameter D, the push rod upper limit screw 102 pitch P, the stopper 103 position size L, and the piston rod pressing head 100 height h, so as to ensure that the weighing calibration is consistent within the accuracy standard range; it is calculated that the piston rod diameter D must be processed according to the gb1800-79js5 grade standard; the cumulative tolerance of the push rod upper limit screw pitch P must be processed according to the tolerance of ±0.05; the stopper position size L and the piston rod pressing head height h must be processed according to ±0.05; this can make the weighing calibration consistent;

[0039] Step 2: According to the precision standard of processing parts in step 1, the diameter D of the piston rod 108, the pitch P of the upper limit screw 102 of the push rod, the position dimension L of the stopper 103, and the height h of the piston rod pressing head 100 are controlled, such as the piston rod diameter D is controlled within the tolerance range of gb1800-79 js5; the cumulative tolerance of the pitch P of the upper limit screw of the push rod is within ±0.05; the processing tolerance of the stopper position dimension L and the height h of the piston rod pressing head is within ±0.05; so that the parts have high interchangeability and assembly consistency, and thus ensure the consistency of weighing calibration;

[0040] Step 3: Make the fixtures required for standardized production, control the high consistency of parts assembly, and ensure the high consistency of weighing calibration; for example, make a pipette profiling positioning fixture, so that the key dimension h1 tolerance after the piston rod push rod and the piston rod pressing head have an interference fit and are pressed within ±0.05;

[0041] Step 4: Since the liquid volume transferred by the single-channel pipette is related to the diameter D of the piston rod 108 and the stroke H of the piston rod, that is, V = πD2 H / 4, when the diameter D of the piston rod 108 is within the tolerance range of gb1800-79js5, the liquid volume transferred by the single-channel pipette can be ensured to be within the standard range by controlling the stroke of the piston rod H. Therefore, an electronic height measuring mechanism can be made to control the stroke of the piston rod H; when the stroke H of the piston rod is within the tolerance of ±0.05, the liquid volume transferred by the single-channel pipette can be ensured to be within the standard range;

[0042] Step 5: Based on the electronic height measurement mechanism, a multi-dimensional calibration robot 300 is manufactured. The multi-dimensional calibration robot 300 is controlled by a computer connection to automatically grasp, measure, and calibrate large batches of single-channel pipettes, so as to achieve high consistency in the mass production of single-channel pipettes and ensure that the mass production of single-channel pipettes is within the standard range, thereby solving the problem of high cost and low efficiency of mass production calibration equipment.

[0043] The single-channel pipette includes a housing, a piston rod pressing head 100, a scale wheel knob 101, a push rod upper limit screw 102, a stopper 103, a push rod lower limit block 104, a piston rod push rod 105, a piston rod return spring 106, a piston rod sealing ring 107, a piston rod 108, a piston cylinder 109 and a suction head 110. The bottom end of the housing is provided with a piston cylinder 109, and the piston rod 108 is sealed in the piston cylinder 109 by the piston rod sealing ring 107, so that when the piston rod 108 moves, a negative pressure or a positive pressure is formed in the piston cylinder 109; the bottom end of the piston cylinder 109 is provided with a suction head 110, so as to absorb or squeeze out liquid through the suction head 110, and the top of the piston rod 108 is provided with a piston rod return spring 106, and the piston rod return spring 106 is located on the middle part of the housing, so that the top of the piston rod 108 and the bottom of the piston rod push rod 105 are always in contact with each other. To maintain contact, a stopper 103 is provided on the piston rod push rod 105, and the piston rod push rod 105 is slidably connected to the top end of the shell, so that the piston rod push rod 105 is pushed upward under the action of the piston rod return spring 106, and stops moving when the stopper 103 hits the push rod upper limit screw rod 102. The piston rod push rod 105 passes through the push rod upper limit screw rod 102 and the push rod lower limit block 104 and is fixed on the piston rod pressing head 100, and the push rod upper limit screw rod 102 and the push rod lower limit block 104 are arranged on the top end of the shell, and the piston rod pressing head 100 is slidably connected to the top end of the shell, and the distance that the stopper 103 moves from the push rod upper limit screw rod 102 to the push rod lower limit block 104 is set to the piston rod stroke H. The top end of the shell is rotatably connected to the scale wheel knob 101, and the inner cavity of the scale wheel knob 101 is slidably connected to the piston rod pressing head 100.

[0044] Wherein: before the single-channel pipette is used, the stopper 103 presses against the lower end surface of the upper limit screw rod 102 of the push rod; when the single-channel pipette is in use, the hand holds the shell, and the thumb presses the piston rod pressing head 100, so that the stopper 103 moves to the lower limit block 104 of the push rod, and the displacement during this period is recorded as the piston rod stroke H, and the piston rod 108 discharges the air in the piston cylinder 109; then according to the ISO8655 operating standard, the suction head 110 is moved into the liquid, and the thumb is slowly released. At this time, the stopper 103 moves the piston rod stroke H distance back to the lower end surface of the upper limit screw rod 102 of the push rod; so that negative pressure is formed in the piston cylinder 109 and the liquid is sucked; it can be seen that the liquid volume transferred by the single-channel pipette is related to the diameter D of the piston rod 108 and the piston rod stroke H, that is: V = πD2 H / 4; the liquid volume accuracy of the single-channel pipette is closely related to the machining accuracy of the piston rod 108 diameter D and the control accuracy of the piston rod stroke H; the liquid volume accuracy of the single-channel pipette must be within the tolerance range of the value displayed by the scale wheel knob 101; the value displayed by the scale wheel knob 101 and the upper limit screw 102 of the push rod are controlled by the rotation of the scale wheel knob 101; when the scale wheel knob 101 rotates clockwise, the lower end surface of the upper limit screw 102 of the push rod moves downward under the spiral rotation, so that the piston rod stroke H becomes smaller, and the value displayed by the scale wheel knob 101 becomes smaller synchronously; when the scale wheel knob 101 rotates counterclockwise When the needle rotates, the lower end surface of the push rod upper limit screw 102 moves upward under the spiral rotation, so that the piston rod stroke H becomes larger, and at the same time, the value displayed by the scale wheel knob 101 increases synchronously; it can be seen that the control accuracy of the piston rod stroke H is related to the pitch P of the push rod upper limit screw 102, the position dimension L of the stopper 103, the dimensional accuracy of the height h of the piston rod pressing head 100 and the assembly accuracy; therefore, the liquid volume accuracy of the single-channel pipette is related to the machining accuracy of the piston rod 108 diameter D, the pitch P of the push rod upper limit screw 102, the position dimension L of the stopper 103, the dimensional accuracy of the height h of the piston rod pressing head 100 and the assembly accuracy.

[0045] The single-channel pipette is housed in an electronic height measurement mechanism;

[0046] The electronic height measuring mechanism comprises an electronic height measuring instrument 200, a slide rail 201, a height measuring probe 202, a column 203 and a pipette profiling positioning fixture 205. A single-channel pipette is arranged in the pipette profiling positioning fixture 205. A column 203 is fixedly installed on the top left side of the pipette profiling positioning fixture 205. A slide rail 201 is fixedly installed on one side of the column 203. The electronic height measuring instrument 200 is fixedly installed on the slide rail 201. A height measuring probe 202 is arranged on the electronic height measuring instrument 200 so that the height measuring probe 202 can contact the piston rod pressing head 100 and measure the piston rod stroke H. The electronic height measuring instrument 200 is connected to a computer so as to upload the measured piston rod stroke H to the computer; thereby calibrating the piston rod stroke H within a tolerance of ±0.05; and ensuring that the liquid volume transferred by the single-channel pipette is within a standard range.

[0047] A multi-dimensional calibration manipulator 300 is provided on one side of the electronic height measurement mechanism to enable full-automatic grasping, measurement and calibration of the single-channel pipette.

[0048] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single-channel pipette calibration method, characterized in that: The specific steps are as follows: Step 1: Calculate the accuracy of the pipette accurately, and based on this, formulate the processing accuracy standards for the diameter D of the piston rod (108), the pitch P of the upper limit screw rod (102), the position size L of the stopper (103), and the height h of the piston rod pressing head (100), so as to ensure that the weighing calibration is consistent within the accuracy standard range; Step 2: According to the precision standard of the parts processed in step 1, the diameter D of the piston rod (108), the pitch P of the upper limit screw rod (102) of the push rod, the position size L of the stopper (103), and the height h of the piston rod pressing head (100) are controlled to ensure that the parts have high interchangeability and assembly consistency, thereby ensuring the consistency of weighing calibration; Step 3: Make the fixtures required for standardized production, control the high consistency of parts assembly, and ensure the high consistency of weighing calibration; Step 4: Since the volume of liquid transferred by the single-channel pipette is related to the diameter D of the piston rod (108) and the stroke H of the piston rod, that is, V = πD2 H / 4, when the diameter D of the piston rod (108) is within the tolerance range of gb1800-79js5, the stroke H of the piston rod can be well controlled to ensure that the volume of liquid transferred by the single-channel pipette is within the standard range. Therefore, an electronic height measuring mechanism can be made to control the stroke H of the piston rod; when the stroke H of the piston rod is within the tolerance of ±0.05, the volume of liquid transferred by the single-channel pipette can be within the standard range. Step 5: Based on the electronic height measurement mechanism, a multi-dimensional calibration robot (300) is manufactured. The multi-dimensional calibration robot (300) is controlled by a computer connection to automatically grasp, measure, and calibrate large batches of single-channel pipettes, so as to achieve high consistency during large-scale production of single-channel pipettes and ensure that the large batches of single-channel pipettes are within the standard range, thereby solving the problem of high cost and low efficiency of large-scale production calibration equipment.

2. A single-channel pipette calibration method according to claim 1, characterized in that: The single-channel pipette comprises a housing, a piston rod pressing head (100), a scale wheel knob (101), a push rod upper limit screw (102), a stopper (103), a push rod lower limit block (104), a piston rod push rod (105), a piston rod return spring (106), a piston rod sealing ring (107), a piston rod (108), a piston cylinder (109) and a suction head (110). The bottom end of the housing is provided with a piston cylinder (109), and the piston rod (108) is sealed in the piston cylinder (109) through the piston rod sealing ring (107), so that when the piston rod (108) moves, negative pressure or positive pressure is formed in the piston cylinder (109); the bottom end of the piston cylinder (109) is provided with a suction head (110) so that liquid can be sucked or squeezed out through the suction head (110).

3. A single-channel pipette calibration method according to claim 2, characterized in that: A piston rod return spring (106) is provided at the top of the piston rod (108), and the piston rod return spring (106) is located in the middle of the housing so that the top of the piston rod (108) is always in contact with the bottom of the piston rod push rod (105).

4. A single-channel pipette calibration method according to claim 3, characterized in that: The piston rod push rod (105) is provided with a stopper (103), and the piston rod push rod (105) is slidably connected to the top end of the housing so that the piston rod push rod (105) is pushed upward under the action of the piston rod return spring (106) and stops moving when the stopper (103) hits the push rod upper limit screw (102).

5. A single-channel pipette calibration method according to claim 4, characterized in that: The piston rod push rod (105) passes through the push rod upper limit screw rod (102) and the push rod lower limit block (104) and is fixed on the piston rod pressing head (100), and the push rod upper limit screw rod (102) and the push rod lower limit block (104) are arranged on the top end of the shell, and the piston rod pressing head (100) is slidably connected to the top end of the shell, and the distance that the stop block (103) moves from the push rod upper limit screw rod (102) to the push rod lower limit block (104) is set as the piston rod stroke H, and the top end of the shell is rotatably connected to a scale wheel knob (101), and the inner cavity of the scale wheel knob (101) is slidably connected to the piston rod pressing head (100).

6. A single-channel pipette calibration method according to claim 5, characterized in that: The single-channel pipette is arranged in the electronic height measurement mechanism; The electronic height measuring mechanism comprises an electronic height measuring instrument (200), a slide rail (201), a height measuring probe (202), a column (203) and a pipette profiling positioning fixture (205); a single-channel pipette is arranged in the pipette profiling positioning fixture (205); and the column (203) is fixedly mounted on the top left side of the pipette profiling positioning fixture (205).

7. A single-channel pipette calibration method according to claim 6, characterized in that: A slide rail (201) is fixedly mounted on one side of the column (203), an electronic height measuring instrument (200) is fixedly mounted on the slide rail (201), and a height measuring probe (202) is provided on the electronic height measuring instrument (200), so that the height measuring probe (202) can contact the piston rod pressing head (100) and measure the piston rod stroke H.

8. A single-channel pipette calibration method according to claim 7, characterized in that: A multi-dimensional calibration manipulator (300) is provided on one side of the electronic height measurement mechanism so as to be able to fully automatically grasp, measure and calibrate the single-channel pipette.

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