Device for measuring inorganic carbon in soil by gravimetric method

Abstract

The invention belongs to the technical field of soil element determination, and particularly relates to a device for determining soil inorganic carbon by a gravimetric method, which comprises a base, a side plate, a sample holder, an injection pump, a solution barrel and a PLC (Programmable Logic Controller), a sample rack, an electronic balance and a magnetic stirrer are arranged on the base; a first stepping motor and a second stepping motor are arranged on the side plate, the first stepping motor is in driving connection with a first lead screw, a first sliding block is arranged on the first lead screw, a telescopic mechanical liquid adding head is arranged on the first sliding block, the telescopic mechanical liquid adding head is connected with an injection pump through a liquid conveying pipe, and an electromagnetic valve is arranged on the liquid conveying pipe; the injection pump is also communicated with the solution barrel; the second stepping motor is in driving connection with the second lead screw, a second sliding block is arranged on the second lead screw, and a telescopic mechanical arm is arranged on the second sliding block. The device is simple in structure, good in stability, good in repeatability and accurate in measurement result.

Description

Technical Field

[0001] The invention belongs to the technical field of soil element determination, in particular to a device for determining soil inorganic carbon by weight method. Background Art

[0002] Carbon in the soil includes inorganic carbon and organic carbon. Soil inorganic carbon mainly refers to various negatively charged carbon-containing inorganic compounds in the soil, including carbonate ions (CO 3 2- , HCO 3 - ), calcium and magnesium carbonate deposits in the soil, and CO in the soil air 2 .

[0003] At present, the main analytical methods for inorganic carbon are gravimetric method, acid-base titration method and non-aqueous titration method. The gravimetric method can determine CO by acid hydrolysis or thermal decomposition. 2 The content of soil inorganic carbon is obtained by measuring the content of soil inorganic carbon. The traditional method is that the test personnel complete the above process manually, which is very laborious and time-consuming. Since soil inorganic carbon is a basic indicator, the test volume is often very large, and there is currently no device that can test multiple samples at a time. Summary of the invention

[0004] The purpose of the present invention is to provide a device for measuring soil inorganic carbon by gravimetric method. The device has simple structure, good stability, good repeatability and accurate measurement results.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A device for determining soil inorganic carbon by gravimetric method, the device comprising a base, a side plate, a sample rack, a syringe pump, a solution barrel and a PLC controller;

[0007] The base is connected to the side plate, and a sample rack, an electronic balance and a magnetic stirrer are arranged on the base; a first stepper motor and a second stepper motor are arranged on the side plate, the first stepper motor is drivingly connected to a first lead screw, a first slider is arranged on the first lead screw, a telescopic mechanical liquid-adding head is arranged on the first slider, the telescopic liquid-adding head is connected to a syringe pump through an infusion tube, and an electromagnetic valve is arranged on the infusion tube; the syringe pump is also connected to a solution barrel;

[0008] The second stepping motor is drivingly connected to the second lead screw, a second slider is arranged on the second lead screw, and a telescopic manipulator is arranged on the second slider;

[0009] The PLC controller is communicatively connected with the electronic balance, the magnetic stirrer, the electromagnetic valve, the injection pump, the first stepping motor, the second stepping motor, the telescopic manipulator and the telescopic liquid adding head.

[0010] The device also includes a sample bottle and a bottle cap, and the sample bottle is placed on the sample rack.

[0011] Preferably, the telescopic manipulator comprises a telescopic rod and a graspable head; one end of the telescopic rod is connected to the second slider, and the other end is connected to the graspable head.

[0012] Preferably, the telescopic liquid-adding head comprises a telescopic manipulator and a liquid-adding head; the end of the telescopic manipulator fixes the liquid-adding head.

[0013] Preferably, the telescopic manipulator comprises a telescopic rod and a graspable head; the graspable head is fixedly connected to the liquid adding head. When the telescopic liquid adding head is arranged on the first slider, at this time, one end of the telescopic rod of the telescopic manipulator is fixed on the first slider, and the other end is connected to the graspable head, and the liquid adding head is fixedly connected to the graspable head.

[0014] The working process of the device of the present invention is as follows: firstly, acid solution is added into the sample bottle and weighed, then the soil sample to be measured is added, stirred and acid hydrolyzed, and weighed twice after acid hydrolysis, and the difference between the two weights is calculated to obtain the content of inorganic carbon in the soil.

[0015] The present invention uses an injection pump + a liquid adding head to add reagents to a sample bottle, and a manipulator is used to grab the sample bottle to a specified position to achieve the purpose of moving to different positions. The content of soil inorganic carbon is calculated by measuring the weight of carbon dioxide. The measurement result of the electronic balance is very accurate, and the result repeatability is very ideal, which is very worthy of promotion. It is simple and convenient to use the device of the present invention to measure soil inorganic carbon. By setting the parameters of the PLC controller, automatic operation can be achieved, which greatly reduces the workload of the experimenter, greatly improves work efficiency, and reduces the cost of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the device for measuring soil inorganic carbon by gravimetric method of the present invention;

[0017] Figure 2 It is a schematic diagram of the structure of the sample bottle;

[0018] Figure 3 It is a schematic diagram of the structure of the bottle cap;

[0019] Reference numerals:

[0020] 1. Base; 2. Side panel; 3. Sample rack; 4. Syringe pump; 5. Solution barrel; 6. PLC controller; 7. Electronic balance; 8. Magnetic stirrer; 9. First stepper motor; 10. First lead screw; 11. First slide block; 12. Telescopic dosing head; 13. Solenoid valve; 14. Second stepper motor; 15. Second lead screw; 16. Second slide block; 17. Telescopic manipulator; 18. Sample bottle; 19. Bottle cap; 20. Rotor. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0022] Example 1

[0023] like Figure 1 As shown, a device for determining soil inorganic carbon by gravimetric method, the device comprises a base 1, a side plate 2, a sample rack 3, a syringe pump 4, a solution barrel 5 and a PLC controller 6;

[0024] The base 1 is connected to the side plate 2, and a sample rack 3, an electronic balance 7 and a magnetic stirrer 8 are arranged on the base 1; a first stepper motor 9 and a second stepper motor 14 are arranged on the side plate 2, the first stepper motor 9 is drivingly connected to a first lead screw 10, a first slider 11 is arranged on the first lead screw 10, a telescopic mechanical liquid adding head 12 is arranged on the first slider 11, the telescopic liquid adding head 12 is connected to a syringe pump 4 through an infusion tube, and a solenoid valve 13 is arranged on the infusion tube; the syringe pump 4 is also connected to a solution barrel 5;

[0025] The second stepper motor 14 is drivingly connected to the second lead screw 15 , a second slider 16 is disposed on the second lead screw 15 , and a telescopic manipulator 17 is disposed on the second slider 16 ; the telescopic manipulator 17 is used to grab the sample bottle.

[0026] The PLC controller 6 is communicatively connected with the electronic balance 7 , the magnetic stirrer 8 , the solenoid valve 13 , the injection pump 4 , the first stepper motor 9 , the second stepper motor 14 and the telescopic manipulator 17 .

[0027] like Figure 2 and Figure 3 As shown, the device further comprises a sample bottle 18 and a bottle cap 19, wherein the sample bottle 18 is placed on the sample rack 3, and a rotor 20 can be placed in the sample bottle for use during magnetic stirring. The sample rack 3 of the present invention is provided with a plurality of positions for placing sample bottles, which can be arranged in parallel or in a circular arrangement.

[0028] The specific testing process of the present invention is as follows:

[0029] 1. After placing the rotor 20 in the sample bottle 18, place the sample bottle 18 in the sample rack 3;

[0030] 2. Start the solution adding (4 mol / L hydrochloric acid solution) program in the PLC controller 6, and the first stepper motor 9 drives the first screw 10 to drive the first slider 11 and the telescopic liquid adding head 12 connected thereto to move to each sample bottle (here, the first screw 10 can move in a straight line, and the telescopic liquid adding head 12 can move in a direction perpendicular to the first screw on the sample rack 3, so that the cooperation between the first screw and the telescopic liquid adding head can realize movement to any position above the sample rack 3, such as sample bottles with different numbers), and when the telescopic liquid adding head 12 reaches the position of the sample bottle with the specified number, the solenoid valve 13 is opened to add 10 mL of solution to each sample bottle 18;

[0031] 3. After the liquid addition is completed, each sample bottle 18 is covered with a bottle cap 19, and the bottle cap can be covered with an EPTFE film;

[0032] 4. Start the weighing program in the PLC controller 6, and the second stepper motor 14 drives the second lead screw 15, driving the second slider 16 and the telescopic manipulator 17 connected thereto to move along the sample rack 3 and grab sample bottle No. 1 and place it on the electronic balance 7 (here the second lead screw 15 can move in a straight line, and the telescopic manipulator 17 can move on the bottom plate 1 and the sample rack 3 in a direction perpendicular to the second lead screw, so that the cooperation between the second lead screw and the telescopic manipulator can achieve movement to any position above the bottom plate 1 and the sample rack 3, such as sample bottles with different numbers and the electronic balance), the electronic balance 7 will automatically record data after stabilization, and then the telescopic manipulator 17 grabs sample bottle No. 1 and puts it back to position No. 1, and then grabs sample bottle No. 2 and weighs it on the electronic balance 7, and repeats this process to the last sample bottle;

[0033] 5. Weigh the soil samples, record the weighing data and input them into the PLC controller in order, add the weighed soil samples into the sample bottles in order, quickly cover the bottles, and place them in the sample rack in order;

[0034] 6. Start the stirring program of the PLC controller 6, and the second stepper motor 14 drives the second lead screw 15, driving the second slider 16 and the telescopic manipulator 17 connected thereto to grab sample bottle No. 1 and place it on the magnetic stirrer (here the second lead screw 15 can move in a straight line, and the telescopic manipulator 17 can move on the bottom plate 1 and the sample rack 3 in a direction perpendicular to the second lead screw, so that the cooperation between the second lead screw and the telescopic manipulator can achieve movement to any position above the bottom plate 1 and the sample rack 3, such as sample bottles with different numbers and a magnetic stirrer), stir (stirring time, stirring speed and stirring times can be set in the PLC controller), then the telescopic manipulator 17 grabs sample bottle No. 1 and puts it back to position 1, and then grabs sample bottle No. 2 and stirs it on the magnetic stirrer, and repeats this process to the last sample bottle;

[0035] 7. After the stirring is completed, the weighing program is started again, and the second stepper motor 14 drives the second lead screw 15, driving the second slider 16 and the telescopic manipulator 17 connected thereto to grab sample bottle No. 1 and place it on the electronic balance 7. After the electronic balance 7 is stable, it will automatically record the data, and then the telescopic manipulator 17 grabs sample bottle No. 1 and puts it back to position 1, and then grabs sample bottle No. 2 and weighs it on the electronic balance 7, and repeats this process until the last sample bottle; after the weighing is completed, the PLC controller calculates the content of soil inorganic carbon and displays it on the display screen of the PLC controller.

[0036] Each component of the present invention can adopt conventional instruments in the field and can be obtained by purchase. For example, the PLC controller adopts Zhongda Youkong integrated machine MM-24MR-12MT-500_ES_B; the injection pump: Runze circulation SY-08 (25mL); the solenoid valve: Alpak DN15; the stepper motor and the lead screw: BT-GWS series micro ball screw pair; the telescopic manipulator is a device with a telescopic rod and a gripping head; the telescopic liquid adding head can adopt the gripping head of the telescopic manipulator to fix the liquid adding head: the electronic balance and the magnetic stirrer are conventional devices in the field.

[0037] The soil inorganic carbon determination of the present invention is much more convenient, and multiple samples can be tested at one time, meeting the testing needs of large quantities of samples, and is very worthy of promotion.

[0038] Any contents not described in detail in the present invention can be based on the conventional technical knowledge in the art.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A device for determining soil inorganic carbon by gravimetric method, characterized in that: The device comprises a base, a side plate, a sample rack, a syringe pump, a solution barrel and a PLC controller; The base is connected to the side plate, and a sample rack, an electronic balance and a magnetic stirrer are arranged on the base; a first stepper motor and a second stepper motor are arranged on the side plate, the first stepper motor is drivingly connected to a first lead screw, a first slider is arranged on the first lead screw, a telescopic mechanical liquid-adding head is arranged on the first slider, the telescopic liquid-adding head is connected to a syringe pump through an infusion tube, and an electromagnetic valve is arranged on the infusion tube; the syringe pump is also connected to a solution barrel; The second stepping motor is drivingly connected to the second lead screw, a second slider is arranged on the second lead screw, and a telescopic manipulator is arranged on the second slider; The PLC controller is communicatively connected with the electronic balance, the magnetic stirrer, the electromagnetic valve, the injection pump, the first stepping motor, the second stepping motor, the telescopic manipulator and the telescopic liquid adding head.

2. The device for determining soil inorganic carbon by gravimetric method according to claim 1, characterized in that: The device also includes a sample bottle and a bottle cap, and the sample bottle is placed on the sample rack.

3. The device for determining soil inorganic carbon by gravimetric method according to claim 1, characterized in that: The telescopic manipulator comprises a telescopic rod and a graspable head; one end of the telescopic rod is connected to the second sliding block, and the other end is connected to the graspable head.

4. The device for determining soil inorganic carbon by gravimetric method according to claim 1, characterized in that: The telescopic liquid-adding head comprises a telescopic manipulator and a liquid-adding head; the end of the telescopic manipulator is fixed with the liquid-adding head.

5. The device for determining soil inorganic carbon by gravimetric method according to claim 4, characterized in that: The telescopic manipulator comprises a telescopic rod and a graspable head; the graspable head is fixedly connected to the liquid adding head.

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