CN206330655U - A kind of hand-held capacity calibration device of pipettor - Google Patents

Abstract

The utility model discloses a capacity calibrating device for a hand-held liquid pipette, which realizes the liquid extraction, transfer, and liquid discharge operations of the pipette by a mechanical device through the rotation of a servo motor, the mutual movement of a ball screw and a slider, etc. The balance and temperature sensor realize the collection of pipetting data. The main feature of the utility model is to realize the automatic collection of data. The device can be combined with conventional methods to realize the automation of single-point calibration pipettes, which reduces the errors caused by single-point repeated operations and large data volume processing. At the same time, the calibration data can be analyzed and a calibration report can be given.

Description

A Handheld Pipette Volume Calibration Device

technical field

The utility model relates to the field of pipettes, in particular to a volume calibration device for a hand-held pipette.

Background technique

Pipettes are widely used in hospitals, health and epidemic prevention stations, blood transfusion stations, biochemical laboratories, environmental laboratories, and food analysis laboratories. They are precision liquid sampling instruments that can quickly and accurately quantify a small amount of liquid samples and test solutions. Sampling and sample addition, for adjustable pipettes, the operator can also adjust the capacity value of the pipette according to actual needs. As a necessary equipment for pipetting, the calibration of its capacity directly affects the measurement results. However, in the long-term use process, operation, temperature, human factors, etc. will affect its accuracy. Insufficient or excessive pipetting may cause production accidents or deviations in research results. In order to ensure that the result data has good precision, accuracy and reliability, it must be calibrated regularly.

The traditional pipette calibration method adopts the measurement method, that is, weigh the quality of the pure water released by the pipette under test within a certain scale, and then obtain the actual volume of the pipette under test based on the density of the water, and then Compare with checkpoint capacity. Since each capacity verification point needs to be detected 6 times according to the national regulations, 18 liquid extraction and discharge operations are required to detect the 3 capacity values of an adjustable pipette. Therefore, the operation steps of this method are repeated, complicated, and Manual operation will bring some errors.

In terms of hardware, the high-degree-of-freedom simulation manipulators produced by some foreign companies can realize the operation of pipettes to a certain extent. However, in the actual use of calibrating pipettes, too many degrees of freedom are not required. Degrees of freedom are wasteful, and the high cost hinders their use in pipette calibration. In terms of software, the pipette calibration system designed in China is also constantly improving, which can efficiently process and analyze a large amount of collected data. However, only the automation of data processing has been realized, and there is still a gap in the automation of pipette control. .

Contents of the invention

The purpose of the utility model is to provide a hand-held pipette volume calibration device to solve the defects in the prior art.

The purpose of this utility is achieved through the following technical solutions: a hand-held pipette volume calibration device, which is composed of the following components: an experimental console, a first servo motor, a first coupling, a first ball screw, two A first bearing, a first ball nut, a first nut seat, a first bracket, a second servo motor, a second coupling, a second ball screw, a second bearing, a second ball nut, a second nut seat, Second bracket, fourth servo motor, guide rod, pipette holding device, circular float, beaker, electronic balance, conical beaker, temperature sensor.

The first servo motor, the two first bearings, the beaker, and the electronic balance are sequentially fixed on the experimental console; the beaker is filled with measuring liquid, and the circular float floats on the measuring liquid; the conical beaker is placed on the electronic balance Above; the temperature sensor is installed in the conical beaker to measure the temperature of the liquid in the conical beaker in real time.

Both ends of the first ball screw are installed on the experimental console through the first bearing, the output shaft of the first servo motor is connected with the first ball screw through the first coupling, and the first ball nut is sleeved on the first ball screw. On the lead screw; the first servo motor drives the first ball screw to rotate, so that the first ball nut moves horizontally; the first nut seat is installed on the top of the first ball nut, and moves horizontally synchronously with the first ball nut; the first bracket vertically Fixed on the first nut seat, perpendicular to the first ball screw, the second servo motor is fixed on the bottom of the first bracket, the two ends of the second ball screw are installed on the first bracket through the second bearing, the second servo motor The output shaft of the motor is connected with the second ball screw through the second coupling, the second ball nut is sleeved on the second ball screw, and the second servo motor drives the second ball screw to rotate, so that the second ball nut Move in the vertical direction; the second nut seat is connected with the second ball nut and moves synchronously with the second ball nut; one end of the second bracket is horizontally fixed on the second nut seat, and the fourth servo motor and the pipette are clamped The device is fixed on the other end of the second bracket, the output shaft of the fourth servo motor is connected with the guide rod, and the guide rod is driven to rotate by the fourth servo motor to realize the pressing of the pipette gun clamped by the pipette clamping device.

The beneficial effect of the utility model is that: the utility model realizes the automation of volume calibration for a single hand-held pipette, greatly reducing repeated operations of calibration workers.

Description of drawings

Fig. 1 is the structural representation of the calibration device of the present utility model;

In the figure, the experimental console 1, the first servo motor 2, the first coupling 3, the first ball screw 4, the first bearing 5, the first ball nut 6, the first nut seat 7, the first bracket 8, Second servo motor 9, second coupling 10, second ball screw 11, second bearing 12, second ball nut 13, second nut seat 14, second bracket 15, fourth servo motor 16, guide rod 17. Pipette holding device 18, circular float 21, beaker 22, electronic balance 23, conical beaker 24, temperature sensor 33.

detailed description

As shown in Figure 1, a hand-held pipette volume calibration device is composed of the following components: an experimental console 1, a first servo motor 2, a first coupling 3, a first ball screw 4, two second A bearing 5, a first ball nut 6, a first nut seat 7, a first bracket 8, a second servo motor 9, a second coupling 10, a second ball screw 11, two second bearings 12, a second Ball nut 13, second nut seat 14, second bracket 15, fourth servo motor 16, guide rod 17, pipette clamping device 18, circular float 21, beaker 22, electronic balance 23, conical beaker 24, temperature sensor 33.

The first servo motor 2, the first coupling 3, the first ball screw 4, the two first bearings 5, the first ball nut 6, and the first nut holder 7 form a horizontal transport system. The first bracket 8, the second The servo motor 9, the second shaft coupling 10, the second ball screw 11, the second bearing 12, the second ball nut 13, and the second nut seat 14 constitute a vertical transportation system, and the two systems work together to achieve the measured displacement The position of the liquid gun is tightly adjusted.

The first servo motor 2, two first bearings 5, a beaker 22, and an electronic balance 23 are sequentially fixed on the experimental console 1; the beaker 22 contains a measuring liquid, and the circular float 21 floats on the measuring liquid; The conical beaker 24 is placed on the electronic balance 23; the temperature sensor 33 is installed in the conical beaker 24 to measure the temperature of the liquid in the conical beaker 24 in real time.

The two ends of the first ball screw 4 are installed on the experimental console 1 through the first bearing 5, the output shaft of the first servo motor 2 is connected with the first ball screw 4 through the first coupling 3, the first ball The nut 6 is set on the first ball screw 4; the first servo motor 2 drives the first ball screw 4 to rotate, so that the first ball nut 6 moves horizontally; the first nut seat 7 is installed on the top of the first ball nut 6, and The first ball nut 6 moves horizontally synchronously; the first bracket 8 is vertically fixed on the first nut seat 7, perpendicular to the first ball screw 4, the second servo motor 9 is fixed on the bottom of the first bracket 8, and the second ball The two ends of the lead screw 11 are installed on the first bracket 8 through the second bearing 12, the output shaft of the second servo motor 9 is connected with the second ball screw 11 through the second coupling 10, and the second ball nut 13 sets On the second ball screw 11, the second servo motor 9 drives the second ball screw 11 to rotate, so that the second ball nut 13 moves in the vertical direction; the second nut seat 14 is connected with the second ball nut 13, Move synchronously with the second ball nut 13; one end of the second bracket 15 is horizontally fixed on the second nut seat 14, the fourth servo motor 16 and the pipette clamping device 18 are fixed on the other end of the second bracket 15, the fourth The output shaft of the servo motor 16 is connected with the guide rod 17, and the guide rod 17 is driven to rotate by the fourth servo motor 16, so as to press the pipette gun clamped by the pipette clamping device 18.

The device described in the utility model realizes the measurement through manual control, and can also cooperate with the upper computer to realize automatic control and carry out fully automatic measurement, as follows:

(1) Control the movement of the first servo motor 2, when the pipette gun clamped by the pipette clamping device 18 is above the beaker, close the first servo motor 2;

(2) Control the movement of the fourth servo motor 16, drive the guide rod 17 to press the top of the pipette gun, and close the fourth servo motor 16 after the pressing action is completed;

(3) Control the movement of the second servo motor 9, so that the second ball nut 13 moves down the distance D1, and the tip of the pipette clamped by the pipette clamping device 18 is inserted into 2-3mm below the liquid surface; then close the second Two servo motors 9;

(4) Reversely control the fourth servo motor 16 until the guide rod 17 resets, turn off the fourth servo motor 16, the pressing effect of the guide rod 17 on the top of the pipette gun disappears, and the pipette gun draws a full-scale measurement liquid from the beaker ;

(5) Control the movement of the second servo motor 9 so that the second ball nut 13 moves up the same distance D1, and then close the second servo motor 9;

(6) obtain initial weight by electronic balance 23, simultaneously, control first servomotor 2 motion, when the pipette gun clamped by pipette clamping device 18 is positioned at the top of conical beaker 24, close first servomotor 2;

(7) Control the movement of the second servo motor 9 so that the second ball nut 13 moves down the distance D2, and the pipette tip held by the pipette clamping device 18 is inserted into the lower part of the conical beaker 24 but does not touch the liquid surface ; Then close the second servo motor 9;

(8) Control the movement of the fourth servo motor 16, drive the guide rod 17 to press the top of the pipette gun, and transfer the full-scale measuring liquid to the conical beaker 24; then reversely control the fourth servo motor 16 until the guide rod 17 resets , turn off the fourth servo motor 16, and the pressing effect of the guide rod 17 on the top of the pipette disappears; and control the movement of the second servo motor 9, so that the second ball nut 13 moves upward by the same distance D2, and then turn off the second servo motor 9.

(9) The weight at the end point is obtained by the electronic balance 23 , and the temperature of the liquid in the conical beaker 24 is obtained by the temperature sensor 33 .

(10) further obtain the corresponding calibration coefficient correlation coefficient K (t) under the liquid temperature through the actual temperature t of the temperature sensor 33, further obtain the actual weight m according to the end point weight and the initial weight, and obtain the actual volume V'=K (t) m.

(11) Perform n times (generally 4-6) measurements according to steps 1 to 10, and obtain the volume data measured under the range V ₁ , which is V ₁₁ '～V _1n ';

(12) Adjust the range of the pipette gun, perform n measurements according to steps 1 to 10, and obtain the volume data V _i1 '～V _in ' under the range V _i ;

(13) According to the measured volume and the actual volume, the relative error and volume repeatability of the pipette are obtained. Among them, the relative error of the capacity under the range V _i is:

in,

The capacity repeatability is: in

Claims (1)

1. A handheld pipettor capacity calibration device, consisting of the following components: the test bed comprises an experimental operating table (1), a first servo motor (2), a first coupler (3), a first ball screw (4), two first bearings (5), a first ball nut (6), a first nut seat (7), a first support (8), a second servo motor (9), a second coupler (10), a second ball screw (11), a second bearing (12), a second ball nut (13), a second nut seat (14), a second support (15), a fourth servo motor (16), a guide rod (17), a pipettor clamping device (18), a circular floater (21), a beaker (22), an electronic balance (23), a conical beaker (24) and a temperature sensor (33);

the first servo motor (2), the two first bearings (5), the beaker (22) and the electronic balance (23) are sequentially fixed on the experiment operating platform (1); the beaker (22) is filled with a measuring liquid, and the circular floater (21) floats on the measuring liquid; the conical beaker (24) is placed on an electronic balance (23); the temperature sensor (33) is arranged in the conical beaker (24);

two ends of a first ball screw (4) are installed on the experiment operating table (1) through first bearings (5), an output shaft of a first servo motor (2) is connected with the first ball screw (4) through a first coupler (3), and a first ball nut (6) is sleeved on the first ball screw (4); the first nut seat (7) is arranged at the top of the first ball nut (6) and moves horizontally synchronously with the first ball nut (6); the first support (8) is vertically fixed on the first nut seat (7) and is perpendicular to the first ball screw (4), the second servo motor (9) is fixed at the bottom of the first support (8), two ends of the second ball screw (11) are installed on the first support (8) through second bearings (12), an output shaft of the second servo motor (9) is connected with the second ball screw (11) through a second coupler (10), and a second ball nut (13) is sleeved on the second ball screw (11); the second nut seat (14) is connected with the second ball nut (13) and moves synchronously with the second ball nut (13); one end of the second support (15) is horizontally fixed on the second nut seat (14), the fourth servo motor (16) and the pipette clamping device (18) are fixed at the other end of the second support (15), an output shaft of the fourth servo motor (16) is connected with the guide rod (17), and the guide rod (17) is driven to rotate by the fourth servo motor (16).