阅读说明：本技术 一种微量精准电位滴定仪和滴定方法 (Micro-precision potentiometric titrator and titration method ) 是由 刘洋 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种微量精准电位滴定仪和滴定方法,包括注射管、支撑架、导柱、控制系统、传动机构、消隙传动装置和定位计量装置,传动机构包括丝杆和同步带轮,注射管安装在丝杆上,丝杆与同步带轮连接,控制系统包括第一电机、第二电机和控制主板,同步带轮与第二电机连接,控制主板分别与第一电机和第二电机连接,第一电机与定位计量装置连接,丝杆与定位计量装置连接,丝杆与支撑架连接,导柱安装在支撑架上,消隙传动装置安装在丝杆上。通过无间隙丝杆传动技术和步进电机高分辨率细分技术,丝杠上下传动时,产生的微量间隙通过丝杆螺母上面自动弹簧调节,正反传动产生的间隙,步进电机高分辨率能够保证每一步精确加样。(The invention discloses a micro-precision potentiometric titrator and a titration method, which comprise an injection tube, a support frame, a guide post, a control system, a transmission mechanism, an anti-backlash transmission device and a positioning and metering device, wherein the transmission mechanism comprises a lead screw and a synchronous belt pulley, the injection tube is arranged on the lead screw, the lead screw is connected with the synchronous belt pulley, the control system comprises a first motor, a second motor and a control main board, the synchronous belt pulley is connected with the second motor, the control main board is respectively connected with the first motor and the second motor, the first motor is connected with the positioning and metering device, the lead screw is connected with the support frame, the guide post is arranged on the support frame, and the anti-backlash transmission device is arranged on the lead screw. Through a gapless screw rod transmission technology and a stepping motor high-resolution subdivision technology, when a screw rod is driven up and down, a generated micro gap is adjusted through an automatic spring on a screw rod nut, and the gap generated by positive and negative transmission and the stepping motor high resolution can ensure accurate sample adding in each step.)

1. The micro-precision potentiometric titrator is characterized by comprising an injection tube, a support frame, a guide pillar, a control system, a transmission mechanism, a gap eliminating transmission device and a positioning metering device, wherein the transmission mechanism comprises a lead screw and a synchronous belt pulley, the injection tube is installed on the lead screw, the lead screw is connected with the synchronous belt pulley, the control system comprises a first motor, a second motor and a control main board, the synchronous belt pulley is connected with the second motor, the control main board is respectively connected with the first motor and the second motor, the first motor is connected with the positioning metering device, the lead screw is connected with the support frame, the guide pillar is installed on the support frame, and the gap eliminating transmission device is installed on the lead screw.

2. The micro-precision potentiometric titrator according to claim 1, wherein the positioning and metering device comprises a first code wheel and a second code wheel, the first code wheel is mounted on a lead screw, and the second code wheel is connected with a first motor.

3. A micro-titrator as claimed in claim 2 wherein the syringe is fitted with a three-way valve, the three-way valve is in communication with the syringe, and the three-way valve is connected to the second dial.

4. The micro-precision potentiometric titrator according to claim 1, wherein the anti-backlash transmission device comprises a spring and a lead screw nut, the lead screw nut is installed on the lead screw, and the spring is sleeved on the lead screw nut.

5. A micro-precision potentiometric titrator according to claim 4, wherein the lead screw nut comprises an upper nut and a lower nut, the upper nut surrounds the lead screw, the lower nut surrounds the lead screw, and the upper nut is connected with the lower nut.

6. The micro-precision potentiometric titrator according to claim 1, further comprising a photoelectric coupler, wherein the photoelectric coupler is connected with the injection tube, and the photoelectric coupler is connected with the control main board.

7. A micro-titrator according to claim 3 wherein the three-way valve is provided with a sample inlet, a sample outlet and a sample sampling port.

8. A method of micropositivity titration using a micropositioner according to claims 1 to 7, comprising the steps of:

step S1: when a sample is loaded, the control main board controls the first motor to rotate, the second code disc rotates to drive the three-way valve to rotate by a precise rotation angle to be communicated with the sample inlet, the control main board controls the second motor, the second motor rotates right and draws downwards, the synchronous belt pulley rotates to drive the lead screw to move downwards, the lead screw drives the piston in the injection tube to draw downwards, and the sample enters the injection tube from the three-way valve to be filled;

step S2: when the dripping is carried out, the control main board controls the first motor to rotate, the second code disc rotates to drive the three-way valve to be connected with the sample outlet at the accurate rotating angle, the control main board controls the second motor to rotate leftwards at the moment, the synchronous belt pulley drives the screw rod to move upwards, the screw rod drives the piston in the injection tube to upwards push out a sample, and the first code disc counts according to the movement of the screw rod.

Technical Field

The invention relates to the technical field of titrators, in particular to a micro-precision potentiometric titrator and a titration method.

Background

Compared with the direct potentiometry, the potentiometry titration method does not need to accurately measure the electrode potential value, so the influence of temperature and liquid junction potential is not important, the accuracy is better than that of the direct potentiometry, the common titration method indicates the titration end point by the color change of an indicator, and if the solution to be measured is colored or turbid, the indication of the end point is difficult or a proper indicator cannot be found at all. Potentiometric titration relies on a sudden electrode potential jump to indicate the endpoint of the titration. Before and after titration reaches an end point, the concentration of ions to be measured in the dropping liquid is continuously changed by n orders of magnitude, a potential jump is caused, and the content of the measured component is calculated by the consumption of the titrant.

However, the potentiometric titrator in the related art has a complex structure and a high difficulty in titration operation, and cannot realize micro-precise titration, which affects titration efficiency.

Disclosure of Invention

In order to solve the problems, the invention provides a micro-precision potentiometric titrator and a titration method, wherein a gapless screw rod transmission technology and a stepping motor high-resolution subdivision technology are adopted, when a screw rod is driven up and down, a generated micro gap is adjusted through an automatic spring on a screw rod nut, the gap is generated by positive and negative transmission, and the stepping motor high-resolution can ensure that each step of accurate sample adding can be realized.

The invention discloses a micro-precision potentiometric titrator which comprises an injection tube, a support frame, a guide post, a control system, a transmission mechanism, a gap eliminating transmission device and a positioning metering device, wherein the transmission mechanism comprises a lead screw and a synchronous belt pulley, the injection tube is installed on the lead screw, the lead screw is connected with the synchronous belt pulley, the control system comprises a first motor, a second motor and a control main board, the synchronous belt pulley is connected with the second motor, the control main board is respectively connected with the first motor and the second motor, the first motor is connected with the positioning metering device, the lead screw is connected with the support frame, the guide post is installed on the support frame, and the gap eliminating transmission device is installed on the lead screw.

In the above scheme, the positioning and metering device includes a first coded disc and a second coded disc, the first coded disc is installed on the screw rod, and the second coded disc is connected with the first motor.

In the above scheme, the injection pipe is provided with the three-way valve, the three-way valve is communicated with the injection pipe, and the three-way valve is connected with the second code disc.

In the above scheme, the anti-backlash transmission device comprises a spring and a screw nut, the screw nut is installed on the screw rod, and the spring is sleeved on the screw nut.

In the above scheme, the feed screw nut includes an upper nut and a lower nut, the upper nut surrounds on the feed screw, the lower nut surrounds on the feed screw, and the upper nut is connected with the lower nut.

In the above scheme, still include optoelectronic coupling, optoelectronic coupling and injection pipe are connected, optoelectronic coupling and control mainboard connection.

In the scheme, the three-way valve is provided with a sample inlet, a sample outlet and a sampling port.

A micro-precision potentiometric titration method applying a micro-precision potentiometric titrator comprises the following steps:

step S1: when a sample is loaded, the control main board controls the first motor to rotate, the second code disc rotates to drive the three-way valve to rotate by a precise rotation angle to be communicated with the sample inlet, the control main board controls the second motor, the second motor rotates right and draws downwards, the synchronous belt pulley rotates to drive the lead screw to move downwards, the lead screw drives the piston in the injection tube to draw downwards, and the sample enters the injection tube from the three-way valve to be filled;

step S2: when the dripping is carried out, the control main board controls the first motor to rotate, the second code disc rotates to drive the three-way valve to be connected with the sample outlet at the accurate rotating angle, the control main board controls the second motor to rotate leftwards at the moment, the synchronous belt pulley drives the screw rod to move upwards, the screw rod drives the piston in the injection tube to upwards push out a sample, and the first code disc counts according to the movement of the screw rod.

The invention has the advantages and beneficial effects that: the invention provides a micro-precision potentiometric titrator and a titration method, wherein a gapless screw rod transmission technology and a stepping motor high-resolution subdivision technology are adopted, when a screw rod is driven up and down, a generated micro gap is automatically adjusted through a spring on a screw rod nut, the gap is generated by positive and negative transmission, and the stepping motor high-resolution can ensure that each step of accurate sample adding can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of the present invention.

Fig. 3 is a front view of the present invention.

Fig. 4 is a cross-sectional view a-a of fig. 3.

Fig. 5 is a right side view of fig. 3.

Fig. 6 is a top view of fig. 3.

In the figure: 1. injection tube 2, support frame 3, guide post 4, photoelectric coupling

5. Screw 6, synchronous pulley 7, first motor 8, second motor

9. A first code disc 10, a second code disc 11, a three-way valve 12 and a screw nut

13. Control mainboard

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in figures 1-6, the invention is a micro-precision potentiometric titrator, which comprises an injection tube 1, a supporting frame 2, a guide post 3 and a control system, drive mechanism, the clearance transmission disappears, photoelectric coupling 4 and location metering device, drive mechanism includes lead screw 5 and synchronous pulley 6, injection pipe 1 installs on lead screw 5, lead screw 5 is connected with synchronous pulley 6, control system includes first motor 7, second motor 8 and control mainboard, synchronous pulley 6 is connected with second motor 8, control mainboard 13 is connected with first motor 7 and second motor 8 respectively, first motor 7 is connected with the location metering device, lead screw 5 is connected with support frame 2, guide pillar 3 is installed on support frame 2, the clearance transmission that disappears installs on lead screw 5, photoelectric coupling 4 is connected with injection pipe 1, photoelectric coupling 4 is connected with the control mainboard.

Further, the positioning and metering device comprises a first coded disc 9 and a second coded disc 10, wherein the first coded disc 9 is installed on the screw rod 5, and the second coded disc 10 is connected with the first motor 7.

The injection tube 1 is provided with a three-way valve 11, the three-way valve 11 is communicated with the injection tube 1, the three-way valve 11 is connected with a second code disc 10, and the three-way valve 11 is provided with a sample inlet, a sample outlet and a sampling port.

Further, the anti-backlash transmission device comprises a spring and a lead screw nut 12, the lead screw nut 12 is installed on the lead screw 5, and the spring is sleeved on the lead screw nut 12; the feed screw nut 12 comprises an upper nut and a lower nut, the upper nut surrounds the feed screw, the lower nut surrounds the feed screw 5, and the upper nut is connected with the lower nut. When the screw rod 5 is driven up and down, the generated micro-gap is automatically adjusted through a spring on the screw rod nut, and the guide pillar 3 slides up and down to fix the stability of the transmission device.

A micro-precision potentiometric titration method applying a micro-precision potentiometric titrator comprises the following steps:

step S1: when a sample is loaded, the control main board 13 controls the first motor 7 to rotate, at the moment, the second code disc 10 rotates to drive the three-way valve 11 to be connected with the sample inlet at a precise rotation angle, at the moment, the control main board 13 controls the second motor 8, the second motor 8 rotates right and draws downwards, the synchronous belt pulley 6 rotates to drive the screw rod 5 to move downwards, the screw rod 5 drives the piston in the injection tube 1 to draw downwards, and the sample enters the injection tube 1 from the three-way valve 11 to be filled;

step S2: when the dripping is carried out, the control mainboard 13 controls the first motor 8 to rotate, the second code disc 10 rotates to drive the three-way valve 11 to be connected with the sample outlet at the accurate rotating angle, the control mainboard 13 controls the second motor 8 to rotate leftwards at the moment, the synchronous belt pulley 6 drives the screw rod 5 to move upwards, the screw rod 5 drives the piston in the injection tube 1 to upwards push out a sample, and the first code disc 9 counts according to the movement of the screw rod 5.

The invention has the advantages that:

1. the potentiometric titration method adopts a high-precision sample adding method, and is ensured by a gapless lead screw transmission technology and a stepping motor high-resolution subdivision technology, the liquid pushing modular design can be matched with a host, when a lead screw is driven up and down, a generated micro gap is adjusted by an automatic spring on a lead screw nut, the gap is generated by positive and negative transmission, the stepping motor high-resolution subdivision technology ensures that no one-step accurate sample adding is carried out, and the whole system realizes closed-loop control through a high-precision code disc;

2. the titration sampling and sample adding modularization can be realized, the host can be matched at will, and 6 maximum recommended modules can work on the titrator at the same time;

3. the sample loading precision reaches 0.0005ML, and the resolution 1/40000 of a burette driver drives a motor;

4. the sample adding and titration speeds are improved, only 10 seconds are needed for 10ML sample adding, the transmission precision is ensured by the gapless lead screw structure, and the PFA coating is sprayed on the surface of the lead screw, so that the lead screw has the functions of lubrication and corrosion resistance;

5. a corrosion-resistant improved quartz injection tube is adopted, the cylindricity of the inner wall is 0.005MM, and the precision is 0.01 MM;

6. the mechanical corrosion-resistant PTFE three-way valve is adopted, and compared with the traditional three-way electromagnetic valve, the mechanical corrosion-resistant PTFE three-way valve has the advantages of high reliability, strong corrosion resistance, small size and high precision.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.