CN211348202U - A simple calibration device for seawater carbon dioxide sensor - Google Patents

Abstract

The utility model discloses a simple calibration device for a seawater carbon dioxide sensor, which belongs to the field of sensor calibration devices. Its main components include carbon dioxide supply device, nitrogen supply device, seawater carbon dioxide sensor to be calibrated, calibrator and benchtop carbon dioxide gas analyzer. The calibrator is the main body for calibration, and the carbon dioxide supply device and the nitrogen supply device are used to supply gas to the calibrator through pipelines to adjust the carbon dioxide concentration in the calibrator. The gas inside the calibrator is circulated through an externally connected gas pipe, the function of which is switched through two three-way valves. The utility model is based on the indirect calibration mechanism of the gas environment, which saves the low-efficiency water-gas mixing balance process, and can greatly improve the calibration efficiency; the high-precision desktop carbon dioxide gas analyzer is used as the real-time monitoring basis for the carbon dioxide concentration during the calibration test process. At the same time, it serves as the data source for the calibration reference value, which ensures the accuracy of the reference value.

Description

A simple calibration device for seawater carbon dioxide sensor

technical field

The utility model belongs to the technical field of sensor calibration, in particular to a simple calibration device for a seawater carbon dioxide sensor.

Background technique

Accurate determination of the partial pressure of carbon dioxide in seawater is the key to revealing the role of the ocean in global climate change. In general, there are two ways to obtain the partial pressure of carbon dioxide in seawater: continuous observation of carbon dioxide by navigation and long-term observation of fixed-point in-situ carbon dioxide sensor. Seawater carbon dioxide sensors based on permeable membrane technology can obtain a large amount of in situ data, and are widely used in the study of global climate change in offshore, oceanic, polar and other sea areas and ocean acidification in sensitive areas such as coral reefs. During the long-term use of the carbon dioxide sensor in the field, due to the influence of biological contamination and the loss of its own components, data drift will inevitably occur, so the sensor needs to be calibrated regularly.

At present, the seawater carbon dioxide sensor calibration device commonly used in the world is very large in size. Usually, the carbon dioxide sensor and the navigation carbon dioxide continuous observation system are placed in the same large pool to ensure that the water bodies measured by the two have the same carbon dioxide partial pressure. calibration. This method requires a huge test site, and has the disadvantage of not being able to rapidly change the carbon dioxide partial pressure in the water body, making it difficult to obtain carbon dioxide partial pressure values with a large concentration gradient, resulting in extremely low calibration efficiency.

Therefore, the establishment of a simple calibration device for seawater carbon dioxide sensor achieves a good balance between calibration accuracy and calibration efficiency, and helps to better play the important role of seawater carbon dioxide sensor in marine scientific research activities.

SUMMARY OF THE INVENTION

The technical problem to be solved by the utility model is to overcome the shortcomings of the existing seawater carbon dioxide sensor calibration device due to its bulky volume and low efficiency, resulting in extremely low usage rate, and to provide an indirect calibration mechanism based on the gas environment, with certain calibration accuracy and higher calibration efficiency. Simple calibration device for seawater carbon dioxide sensor.

The concrete technical scheme that the utility model adopts is as follows:

A calibration device for a seawater carbon dioxide sensor, comprising a carbon dioxide supply device, a nitrogen supply device, a seawater carbon dioxide sensor to be calibrated, a calibrator and a desktop carbon dioxide gas analyzer; the calibrator is a sealed container with a gas inlet and a gas inlet on the top. outlet; the seawater carbon dioxide sensor to be calibrated is suspended in the inner cavity of the calibrator through a fixed frame; the gas inlet is connected to the outlet of the two-in-one-out three-way valve through a trachea, and the gas outlet is sequentially connected to the air pump by the trachea , and the gas flowmeter is connected to the detection inlet of the desktop carbon dioxide gas analyzer; the detection outlet of the desktop carbon dioxide gas analyzer is connected by the gas pipe to the inlet of the one-in, two-out three-way valve, and the first one of the one-in, two-out three-way valve is connected. The outlet is vented, and the second outlet of the one-in, two-out three-way valve is connected to the first inlet of the two-in, one-out three-way valve; the carbon dioxide supply device includes a carbon dioxide storage device and a first pressure reducing device sequentially connected by a carbon dioxide pipeline. The nitrogen supply device includes a nitrogen storage device and a second pressure reducing valve sequentially connected by a nitrogen pipeline; the carbon dioxide pipeline and the nitrogen pipeline end are merged into a gas supply pipeline and then connected to a two-in-one-out three-way valve The second inlet of the calibrator is used to supply gas into the calibrator.

Preferably, the trachea passing through the gas inlet extends into the bottom of the cavity of the calibrator, and the trachea inlet passing through the gas outlet is located at the top of the cavity of the calibrator.

Preferably, the calibrator is a cylindrical casing, and the rest positions except for the gas inlet and the gas outlet are sealed.

Preferably, the calibrator is made of plexiglass.

Preferably, the carbon dioxide storage device is a carbon dioxide gas cylinder.

Preferably, the nitrogen storage device is a nitrogen cylinder.

Preferably, there is a seal between the gas inlet and the gas outlet and the connected gas pipe.

Preferably, the first pressure reducing valve and the second pressure reducing valve are both pressure reducing valves with adjustable opening degrees.

Compared with the prior art, the utility model has the following beneficial effects:

The simple device for the calibration of the seawater carbon dioxide sensor designed by the utility model is based on the indirect calibration mechanism of the gas environment, eliminating the low-efficiency water-gas mixing balance process, and can greatly improve the calibration efficiency; using a high-precision desktop carbon dioxide gas analyzer The instrument is used as the real-time monitoring basis for the carbon dioxide concentration during the calibration test process, and at the same time as the data source of the calibration reference value, which ensures the accuracy of the reference value; during the test process, the whole system is kept sealed, and the carbon dioxide concentration is continuously measured through the circulating gas path, which can ensure The carbon dioxide concentration in the calibrator remains constant during calibration.

Description of drawings

Fig. 1 is the schematic diagram of the present utility model;

In the figure: seawater carbon dioxide sensor to be calibrated 1, calibrator 2, carbon dioxide storage equipment 3, nitrogen storage equipment 4, first pressure reducing valve 5, second pressure reducing valve 6, two-in-one-out three-way valve 7, gas inlet /8. Gas outlet 9, gas pump 10, gas flow meter 11, desktop carbon dioxide gas analyzer 12, one-in, two-out three-way valve 13.

Detailed ways

The present utility model will be further elaborated and described below with reference to the accompanying drawings and specific embodiments. The technical features of the various embodiments of the present invention can be combined correspondingly on the premise that there is no conflict with each other.

As shown in FIG. 1, it is a simple calibration device for a seawater carbon dioxide sensor provided in an embodiment of the present invention, and its main components include a carbon dioxide supply device, a nitrogen supply device, a seawater carbon dioxide sensor 1 to be calibrated, and a calibrator 2. and a benchtop carbon dioxide gas analyzer 12 . The calibrator 2 is the main body for calibration, and the carbon dioxide supply device and the nitrogen supply device are used to supply gas into the calibrator 2 through pipelines to adjust the carbon dioxide concentration in the calibrator 2 . Calibrator 2 is a cylindrical sealed container made of plexiglass for easy viewing of the inside. The calibrator 2 is equipped with a seawater carbon dioxide sensor 1 to be calibrated, and the seawater carbon dioxide sensor 1 to be calibrated is suspended in the inner cavity of the calibrator 2 through a fixing frame. The gas inside the calibrator 2 is circulated through the externally connected gas pipe, and its function switching is realized by two three-way valves; one of them is a two-in-one-out three-way valve 7, which has two inlets and one outlet, and one of the two inlets is selected. Connected with the outlet; the other is a one-in-two-out three-way valve 13, which has one inlet and two outlets, and one of the two outlets is connected to the inlet.

The top of the calibrator 2 is provided with a gas inlet 8 and a gas outlet 9 , and the entire calibrator 2 is kept sealed except for the gas inlet 8 and the gas outlet 9 . The gas inlet 8 is connected to the outlet of the two-in-one-out three-way valve 7 through a gas pipe. The gas outlet 9 is connected to the gas pump 10 and the gas flow meter 11 in sequence by the gas pipe, and then is connected to the detection inlet of the desktop carbon dioxide gas analyzer 12 . The detection outlet of the desktop carbon dioxide gas analyzer 12 is connected to the inlet of the one-in, two-out three-way valve 13 by a gas pipe, the first outlet of the one-in, two-out three-way valve 13 is vented and connected to the atmosphere, and the first outlet of the one-in, two-out three-way valve 13 is connected to the atmosphere. The second outlet is connected to the first inlet of the two-in-one-out three-way valve 7 . The carbon dioxide supply device includes a carbon dioxide storage device 3 and a first pressure reducing valve 5 connected in sequence by a carbon dioxide pipeline, and the nitrogen supply device includes a nitrogen storage device 4 and a second pressure reducing valve 6 connected by a nitrogen pipeline in sequence. The ends of the carbon dioxide pipeline and the nitrogen pipeline are combined into a gas supply pipeline and then connected to the second inlet of the two-in-one-out three-way valve 7 for supplying gas into the calibrator 2 . In this embodiment, in order to make the gas in the calibrator 2 be replaced by the gas inputted by the gas supply pipeline as much as possible, the trachea inserted at the gas inlet 8 should extend into the bottom of the inner cavity of the calibrator, and pass through the gas outlet 9 The trachea extends slightly into the top of the lumen of the calibrator. In this embodiment, the carbon dioxide storage device 3 is a carbon dioxide gas cylinder, and the nitrogen storage device 4 is a nitrogen gas cylinder. Of course, other high-pressure gas storage devices can also be used. In addition, all the connections between the gas pipes of the device and the gas inlet 8 and gas outlet 9 are sealed.

The first pressure reducing valve 5 and the second pressure reducing valve 6 are both pressure reducing valves with adjustable openings. By adjusting the opening degrees between the two, the proportion of carbon dioxide in the gas entering the calibrator 2 can be controlled, thereby Change the CO2 concentration of Calibrator 2.

The following uses a desktop carbon dioxide gas analyzer 12 and a seawater carbon dioxide sensor 1 (carbon dioxide sensor to be calibrated) as an example to further illustrate the operation method when the device of the present invention is used for seawater carbon dioxide sensor calibration, specifically comprising the following steps:

(1) Complete the connection of each component of the device as shown in Figure 1, open the desktop carbon dioxide gas analyzer 12 and the seawater carbon dioxide sensor 1, and open the operating procedure;

(2) Adjust and connect the inlet end of the two-in-one-out three-way valve 7 to the air supply pipeline, adjust the gas outlet end of the one-in, two-out three-way valve 13 to the venting position, turn on the air pump 10, and adjust the gas flow meter 11, so that The gas flow rate in the pipeline meets the detection requirements of the desktop carbon dioxide gas analyzer 12;

(3) According to the relationship between the carbon dioxide concentration in the calibrator 2 and the control target value, adjust the opening of the first pressure reducing valve 5 and the second pressure reducing valve 6 and then control the flow ratio of the two gases, so that the gas supply pipeline is mixed to obtain a suitable the carbon dioxide concentration, and pass it into the calibrator 2;

(4) Continue to observe the reading of the desktop carbon dioxide gas analyzer 12. When the measured value reaches 800 μatm, close the gas pipeline, and adjust the outlet end of the one-in-two-out three-way valve 13 to connect the two-in-one-out three-way valve. The first inlet of the valve 7, the inlet end of the two-in-one-out three-way valve 7 is also adjusted to communicate with the second outlet of the one-in, two-out three-way valve 13, so that the air supply pipeline no longer takes in air, and the gas is only in the calibrator. 2. Internal circulation between the desktop carbon dioxide gas analyzer 12 to keep the internal carbon dioxide concentration constant;

(5) use the desktop carbon dioxide gas analyzer 12 and the seawater carbon dioxide sensor 1 to measure the carbon dioxide concentration in the calibrator 2 simultaneously, and record the synchronous detection value of the desktop carbon dioxide gas analyzer 12 and the seawater carbon dioxide sensor 1 respectively;

(6) Repeat steps (2) to (5), and sequentially acquire the synchronous detection of the benchtop carbon dioxide gas analyzer 12 and the seawater carbon dioxide sensor 1 under the conditions that the carbon dioxide concentration in the calibrator 2 is 700, 600, 500, 400, 300, 200 μatm value;

(7) The measurement value of the seawater carbon dioxide sensor 1 is calibrated using the measurement value of the table-top carbon dioxide gas analyzer 12 as the reference value.

The above-mentioned embodiment is only a preferred solution of the present invention, but is not intended to limit the present invention. Various changes and modifications can also be made by those of ordinary skill in the relevant technical field without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent replacement or equivalent transformation all fall within the protection scope of the present invention.

Claims (8)

1. A simple calibrating device for a seawater carbon dioxide sensor is characterized by comprising a carbon dioxide supply device, a nitrogen supply device, a seawater carbon dioxide sensor (1) to be calibrated, a calibrator (2) and a desk-top carbon dioxide gas analyzer (12); the calibrator (2) is a sealed container, and the top of the calibrator is provided with a gas inlet (8) and a gas outlet (9); the seawater carbon dioxide sensor (1) to be calibrated is suspended and erected in the inner cavity of the calibrator (2) through a fixing frame; the gas inlet (8) is connected with the outlets of the two-inlet one-outlet three-way valve (7) through gas pipes, and the gas outlet (9) is connected with a gas pump (10) and a gas flowmeter (11) in sequence through the gas pipes and then is connected to the detection inlet of a table-type carbon dioxide gas analyzer (12); a detection outlet of the desk type carbon dioxide gas analyzer (12) is connected to inlets of a first inlet and a second outlet three-way valves (13) through a gas pipe, a first outlet of the first inlet and the second outlet three-way valves (13) is emptied, and a second outlet of the first inlet and the second outlet three-way valves (13) is connected to a first inlet of the two inlet and one outlet three-way valves (7); the carbon dioxide supply device comprises carbon dioxide storage equipment (3) and a first pressure reducing valve (5) which are sequentially connected through a carbon dioxide pipeline, and the nitrogen supply device comprises nitrogen storage equipment (4) and a second pressure reducing valve (6) which are sequentially connected through a nitrogen pipeline; and the tail ends of the carbon dioxide pipeline and the nitrogen pipeline are converged into a gas supply pipeline and then are connected to a second inlet of the two-inlet one-outlet three-way valve (7) for supplying gas into the calibrator (2).

2. The simple calibrating device for the seawater carbon dioxide sensor is characterized in that a gas pipe passing through the gas inlet (8) extends into the bottom of the inner cavity of the calibrator (2), and a gas pipe inlet passing through the gas outlet (9) is positioned at the top of the inner cavity of the calibrator (2).

3. The simple calibrating device for the seawater carbon dioxide sensor as claimed in claim 1, wherein the calibrator (2) is a cylindrical housing sealed at the rest positions except the gas inlet (8) and the gas outlet (9).

4. The simple calibrating device for the seawater carbon dioxide sensor is characterized in that the calibrator (2) is made of organic glass.

5. The simple calibration device for seawater carbon dioxide sensor according to claim 1, wherein the carbon dioxide storage device (3) is a carbon dioxide cylinder.

6. The simple calibration device for the seawater carbon dioxide sensor according to claim 1, wherein the nitrogen storage device (4) is a nitrogen cylinder.

7. The simple calibration device for seawater carbon dioxide sensor as claimed in claim 1, wherein the gas inlet (8) and the gas outlet (9) are sealed with the connected gas pipe.

8. The simple calibration device for the seawater carbon dioxide sensor as claimed in claim 1, wherein the first pressure reducing valve (5) and the second pressure reducing valve (6) are both pressure reducing valves with adjustable opening degrees.

Images