CN109939759A - A high-precision double-tube acid-base universal burette - Google Patents

Abstract

The invention discloses a high-precision double-tube acid-base universal burette, which relates to the technical field of chemical experimental instruments. The invention includes an outer scale tube body, an inner scale tube body, and a polytetrafluoroethylene cock. The outer scale tube body is provided with an inner scale tube body with a small diameter; the outer wall of the inner scale tube is provided with three brackets, and the three brackets are connected to the outer scale tube. The inner wall of the body is in smooth contact; the lower end of the inner scale tube body is connected with a piston with a flat bottom surface with a piston through hole; the piston has a certain friction force with the inner wall of the outer scale tube, and the friction force is slightly greater than the weight of the inner scale tube. Under the action of external force, the inner scale tube body will not slide down automatically; the upper end of the inner scale tube body is provided with three blocking sheets and an inner tube cap with a through hole of the inner tube cap. Through the design of the inner and outer double-scale tube bodies, the invention can accurately read the percentile of the volume of the burette reagent, and through the design of the oblong through-hole cock and the needle-shaped tip with smaller aperture and thinner tube wall, the invention can effectively improve the The ability to control the flow rate of the reagent released by the burette solves the problems of inaccurate data measured by the traditional burette.

Description

A high-precision double-tube acid-base universal burette

technical field

The invention belongs to the technical field of chemical experimental instruments, in particular to a high-precision double-tube acid-base universal burette.

Background technique

Burettes are commonly used experimental instruments in biological and chemical experiments. They can be used to release and measure the amount and volume of reagents required for chemical reactions. Therefore, the accuracy of reagent volume determination directly affects the experimental results.

At present, the traditional burettes used in the laboratory are divided into two types: basic burettes and acid burettes. The capacity is generally 25mL and 50mL. The minimum scale value of the volume is generally 0.1mL. When reading, only the tenth of the reagent volume can be read. The percentile needs to be estimated, so the accuracy of the reading is not high. In addition, the inner diameter of the traditional burette is relatively large, and the scale value does not change significantly when a small amount of reagent in the burette is dripped, resulting in a large error in the reading. The cock through hole of the traditional acid burette is generally circular. When the cock with this through hole rotates, the rotation angle and the change of the opening and closing area of the through hole change unevenly. The cock is not conducive to the control of the reagent flow. At the same time, the cock of the traditional acid burette is generally made of glass, so the acid burette cannot contain alkaline reagents; the traditional basic burette has a rubber structure, so the basic burette cannot be installed in it. Acid reagents. The tip of the tip of the tip of the traditional burette has a large aperture, the tip of the tip is thick, and the tube wall is thick, resulting in a large adhesion between the droplet and the tip of the tip, so that the droplet volume of the reagent is larger. The volume of droplets dropped from the tip is about 0.05ml, that is, about 20 drops are 1ml, which can easily lead to large errors in experiments that require high accuracy.

To sum up, there are the following problems and defects in the experiment with the traditional burette: First, the reading is inaccurate, and the percentile of the reagent volume needs to be estimated; second, the flow rate of the reagent is not easy to control; third, the volume of the droplet of the reagent is relatively large. ; Fourth, the acid burette or basic burette cannot be used universally.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-precision double-tube acid-base universal burette. Through the design of the inner and outer double-scale tube bodies, the percentile of the reagent volume of the burette can be accurately read. The design of the cock can improve the ability to control the flow rate of the reagent discharged from the burette, and can achieve the purpose of universal acid and alkali. and so on.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

The invention is a high-precision double-tube acid-base universal burette, which comprises an outer scale tube body, an inner scale tube body and a polytetrafluoroethylene cock.

The outer scale tube body is provided with an inner scale tube body with a small diameter; the outer wall of the inner scale tube body is provided with three brackets, and the three brackets are in smooth contact with the inner wall of the outer scale tube body; the lower end of the inner scale tube body is connected with a There is a piston with a flat bottom surface of the piston through hole; the piston has a certain friction force with the inner wall of the outer scale tube, and the friction force is slightly larger than the weight force of the inner scale tube, and the inner scale tube body will not automatically slide down without external force The upper end of the inner scale tube body is provided with a resist sheet and an inner tube cap with an inner tube cap through hole; The lower end of the body is provided with a needle-shaped tip.

Further, the through hole of the polytetrafluoroethylene cock is an oblong through hole.

Further, the needle-shaped tip is a needle-shaped tip with a smaller hole diameter and a thinner tube wall in the direction of the tip, and a protective sleeve is provided on the outer peripheral side of the needle-shaped tip.

The present invention has the following beneficial effects:

Through the design of the inner and outer double-scale tube bodies, the invention can accurately read the percentile of the reagent volume of the burette, thereby effectively improving the reading accuracy of the burette; The burette releases the ability to control the flow of reagents, and achieves the purpose of acid-base general use; through the design of the needle-shaped tip, the droplet volume of the reagents is reduced, and the accuracy of chemical experiments is improved.

Of course, it is not necessary for any product embodying the present invention to achieve all of the above-described advantages simultaneously.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the overall structure schematic diagram of a kind of high-precision double-tube acid-base universal burette of the present invention;

Fig. 2 is the partial appearance diagram of a kind of high-precision double-tube acid-base universal burette of the present invention;

Fig. 3 is the partial structure schematic diagram of a kind of high-precision double-tube acid-base universal burette of the present invention;

FIG. 4 is a schematic structural diagram of the inner tube cap of a high-precision double-tube acid-base universal burette of the present invention;

5 is a cross-sectional view of a double-tube cross-section of a high-precision double-tube acid-base universal burette of the present invention;

6 is a cross-sectional view of a needle-shaped tip of a high-precision double-tube acid-base universal burette of the present invention;

In the accompanying drawings, the list of components represented by each number is as follows:

1-Outer scale tube body, 2-Inner scale tube body, 3-Bracket, 4-Piston, 5-Piston through hole, 6-Inner tube cap through hole, 7-Inner tube cap, 8-Blocker, 9-Length Round through hole, 10-pin tip, 11-protective sleeve, 12-teflon stopcock.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to Figure 1, the present invention is a high-precision double-tube acid-base universal burette, comprising an outer scale tube body 1, an inner scale tube body 2, and a polytetrafluoroethylene cock 12; the outer scale tube body 1 is provided with a small The inner scale pipe body 2 of the pipe diameter; the outer wall of the inner scale pipe body 2 is provided with three brackets 3, and the three brackets 3 are in smooth contact with the inner wall of the outer scale pipe body 1; the lower end of the inner scale pipe body 2 is connected with a piston through hole 5. Piston 4 with a flat bottom surface; piston 4 has a certain frictional force with the inner wall of the outer scale tube body 1, and the friction force is slightly larger than the weight force of the inner scale tube body, and the inner scale tube body will not slide down automatically without external force; 2. The upper end is provided with a resistance piece 8 and an inner tube cap 7 with an inner tube cap through hole 6; Vinyl cock 12; the lower end of the outer scale tube body 1 is provided with a needle-shaped tip 10 with a smaller aperture and a thinner tube wall toward the tip of the tip;

As shown in Figure 2-6, in order to improve the accuracy of the measurement data of the burette, an auxiliary measurement reading structure is added inside the outer scale body 1 of the burette, that is, an inner scale tube whose diameter is smaller than that of the outer scale body 1 Body 2, and the volume scale value is also engraved on the inner scale tube body 2, its capacity is greater than 1m, the minimum volume scale value is 0.01ml or other values, and its inner cavity cross-sectional area is the outer scale tube body 1. The inner cavity cross-sectional area 1/5, or 1/10 or other ratios; when reading is required, push the inner scale tube body 2 down to the position where the outer scale tube body 1 has an accurate scale value, and ensure that the inner scale tube body 2 is squeezed into a certain amount When the reagent enters the inner scale tube body 2 from the outer scale tube body 1 through the piston through hole 5, the percentile of the reagent volume can be easily and accurately read, and the reading of the reagent volume is the outer scale tube body 1 The sum of the reading at the bottom surface of the piston 4 and the reading at the lowest position of the reagent concave liquid level in the inner scale tube body 2; in order to avoid the shaking of the inner scale tube body 2, three brackets 3 are used to stabilize the inner scale tube body 2, and at the same time In order to avoid the problem that the inner scale tube body 2 is pushed too far into the outer scale tube body 1 and it is inconvenient to take out, three blocking pieces 8 are provided to prevent the inner scale tube body 2 from being completely pushed into the outer scale tube body 1; For the problem that the flow rate is not easy to control, set the circular through hole of the cock as an oblong through hole 9, and slowly rotate the polytetrafluoroethylene cock 12 when using the burette, so that the flow rate of the released reagent can be uniformly controlled, thereby improving the control of the reagent flow rate. In order to improve the efficiency of the experiment, for some experiments in which the amount of reagents can be predicted through chemical equations and other methods, and the flow rate of the released reagents does not affect the experimental results, the closed inner cap through hole 6 can be used. Slowly squeeze the inner cap 7 downward to increase the flow rate of the reagent, and stop the squeezing before the dosage of the reagent reaches the pre-estimated reagent dosage. The tip of the burette is set to a needle-shaped tip 10 with a smaller aperture and thinner tube wall toward the tip of the tip, so that the adhesion between the tip of the tip and the droplet is reduced, and the droplet volume is reduced. The purpose is to add a protective cover 11 to the needle-shaped tip 10 to protect the tip of the needle-shaped tip 10;

In the description of this specification, description with reference to the terms "one embodiment," "example," "specific example," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the present invention. in one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-disclosed preferred embodiments of the present invention are provided only to help illustrate the present invention. The preferred embodiments do not exhaust all the details, nor do they limit the invention to only the described embodiments. Obviously, many modifications and variations are possible in light of the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (3)

1. a kind of two-tube acid-base universal burette of high-precision, including EXT scale tube body (1), interior scale tube body (2), polytetrafluoroethylene (PTFE) Cock (12), it is characterised in that:

The interior scale tube body (2) of small diameter tube is equipped in the EXT scale tube body (1)；Interior scale tube body (2) outer wall is equipped with three Bracket (3), three brackets (3) contact with the inner wall smooth of EXT scale tube body (1)；Interior scale tube body (2) the lower end connection The piston (4) for having the bottom surface equipped with piston hole (5) straight；The piston (4) has frictional force to connect with EXT scale tube body (1) inner wall Touching；Interior scale tube body (2) upper end is equipped with resistance piece (8)；Interior scale tube body (2) upper end is equipped with and opens up interior pipe cap through-hole (6) interior pipe cap (7)；The position of the control reagent flow of the EXT scale tube body (1) is plugged with polytetrafluoroethylene (PTFE) cock (12)； EXT scale tube body (1) lower end is equipped with aciculiform point mouth (10).

2. the two-tube acid-base universal burette of a kind of high-precision according to claim 1, which is characterized in that the polytetrafluoroethyl-ne The through-hole of alkene cock (12) is oblong through-hole (9).

3. the two-tube acid-base universal burette of a kind of high-precision according to claim 1, which is characterized in that the aciculiform point mouth (10) to become the needle-like point mouth (10) that small, tube wall becomes thin to the sharp-tongued extreme direction aperture of point, needle-like point mouth (10) peripheral side, which is equipped with, to be protected Sheath (11).