Efficient water activity testing equipment

Abstract

The utility model discloses efficient moisture activity testing equipment, which comprises a temperature and humidity sensor, a box body and a box cover, the upper end face of the box body is provided with a sample accommodating cavity and a sensor accommodating cavity which are separated from each other, the upper end face of the box body is provided with a first annular groove, and the upper end face of the box body is provided with a second annular groove. A first annular groove is formed in the box body, the sample containing cavity and the sensor containing cavity are both located in the first annular groove, a first sealing ring is arranged in the first annular groove, the box cover and the box body are connected through a plurality of bolts, after the bolts are screwed down, the first sealing ring is pressed, and a certain gap is formed between the box body and the box cover; the temperature and humidity sensor is arranged at the position, corresponding to the sensor containing cavity, of the box cover, and a sealing structure is arranged between the temperature and humidity sensor and the box cover. According to the utility model, the sample accommodating cavity and the sensor accommodating cavity are separately arranged, so that the headspace space is effectively reduced, the balance time of the sample to be tested and the headspace is shortened, the test efficiency is improved, and the test time is shortened.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the water activity test technical field, specifically relates to a kind of efficient water activity test equipment. BACKGROUND

[0002] Water activity is the ratio of the vapor pressure of water in a sample at a specific temperature to the saturated vapor pressure of pure water at the same temperature. Water activity has a wide range of applications in the fields of food shelf life prediction, foodborne pathogen control, and battery research and development.

[0003] The most mainstream testing method at present is headspace relative humidity measurement method, which indirectly calculates the water activity value at the temperature by determining the temperature and relative humidity of the headspace space where the sensor is located after equilibrium (equilibrium refers to the vapor pressure of the sample and headspace space reaches equilibrium).

[0004] The water activity test equipment used in this method is shown in Figure 1 The high-precision sensor used in this water activity test equipment has a large inherent volume, resulting in a large headspace volume. The larger the headspace volume, the longer the time required for the sample and headspace to reach equilibrium. Therefore, the large headspace volume results in a long testing time for the related test equipment. In addition, there is a large difference between the original vapor pressure of the sample and the vapor pressure after the sample and headspace reach equilibrium, resulting in low testing accuracy of the headspace relative humidity measurement method.

[0005] Based on this, the patent designs a kind of efficient water activity test equipment, by separating sample space and headspace space, converting from upper and lower structure to left and right structure, thereby greatly reducing the volume of headspace space, effectively improving testing speed and accuracy. UTILITY MODEL CONTENT

[0006] The utility model aims to provide a kind of efficient water activity test equipment, to improve the problem that the high-precision sensor used in the existing water activity test equipment has a large inherent volume, resulting in a large headspace volume, and further resulting in long testing time.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions:

[0008] The utility model provides a high -efficient water activity test equipment, including temperature and humidity sensor, still include box and box cover, the upper end surface of box is provided with the sample accommodating cavity and sensor accommodating cavity apart, the upper end surface of box is provided with first annular groove, the sample accommodating cavity and sensor accommodating cavity all are located in first annonal groove, first annular groove is provided with first sealing washer, the box cover and box are connected through a plurality of bolts, after the bolt is screwed, the first sealing washer is pressed tightly, and there is a certain gap between box cover and box, temperature and humidity sensor set up in the position of box cover corresponding sensor accommodating cavity, temperature and humidity sensor with box cover between setting has sealing structure.

[0009] Preferably, the sensor accommodating cavity includes an upper rectangular hole part and a lower rectangular hole part, the length and width of the upper rectangular hole part are greater than those of the lower rectangular hole part, and the upper rectangular hole part and the lower rectangular hole part are used for accommodating the head part and the rod part of the temperature and humidity sensor, respectively.

[0010] Preferably, the box body is cylindrical as a whole, the box body is made of aluminum alloy, and the box body is an integral molding structure.

[0011] Preferably, the box cover is disc-shaped as a whole, the box cover is made of aluminum alloy, and the diameter of the box cover is the same as that of the box body.

[0012] Preferably, the first annular groove is a circular annular groove, and the first annular groove is arranged along the common central axis of the box body.

[0013] Preferably, the upper end surface of the box body is uniformly provided with at least four threaded mounting holes along the circumferential direction thereof, each threaded mounting hole is located outside the first annular groove, the box cover is provided with mounting through holes corresponding to the threaded mounting holes one by one, and the rod part of the bolt passes through the mounting through holes and is screwed into the threaded mounting holes.

[0014] Preferably, a weight-reducing cavity is arranged below the sample accommodating cavity, and the lower end of the weight-reducing cavity is open.

[0015] Preferably, the utility model further includes a filling sheet, the shape of the filling sheet is matched with the shape of the sample accommodating cavity, the filling sheet can be put into the sample accommodating cavity and taken out of the sample accommodating cavity.

[0016] Preferably, the filling sheet is made of metal material, preferably aluminum alloy, and the shapes of the filling sheet and the sample accommodating cavity are semicircular.

[0017] Preferably, the box cover is provided with a hole for mounting the head part of the temperature and humidity sensor, a second annular groove is arranged on the hole wall of the hole, and a second sealing washer is arranged in the second annular groove.

[0018] Compared with the prior art, the utility model has the beneficial effects that:

[0019] 1. The utility model sets the sample accommodating chamber and the sensor accommodating chamber separately, which effectively reduces the headspace, thus shortening the time for the sample to be tested and the headspace to reach equilibrium, improving test efficiency and reducing test time.

[0020] 2. The sensor accommodating cavity of the present invention includes an upper rectangular hole portion and a lower rectangular hole portion. The sizes of the upper rectangular hole portion and the lower rectangular hole portion are respectively adapted to the head portion and the rod portion of the temperature and humidity sensor, thereby achieving the effect of further reducing the headspace.

[0021] 3. The utility model is provided with a filling piece, which is made of aluminum alloy. It not only has good heat transfer properties, but can also be used to adjust the amount of sample to be tested. By appropriately reducing the amount of sample used, the water activity can still be accurately measured at a faster speed.

[0022] 4. The utility model has the advantages of high measurement accuracy, good sealing and low manufacturing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of existing water activity testing equipment;

[0024] Figure 2 It is a structural diagram of the utility model;

[0025] Figure 3 It is a cross-sectional schematic diagram of the box body of the present utility model;

[0026] Figure 4 It is a bottom view of the box body of the utility model;

[0027] Figure 5 It is a structural diagram of the box cover of the utility model;

[0028] Figure 6 This is a structural diagram of a filling piece of the present invention;

[0029] Figure 7 This is a comparison chart of the changes in water activity values ​​in egg white powder (a), egg powder (b), and egg yolk powder (c) measured by the utility model and traditional testing equipment;

[0030] In the figure: 1. Box body; 11. Sample accommodating chamber; 12. Sensor accommodating chamber; 121. Upper rectangular hole; 122. Lower rectangular hole; 13. First annular groove; 14. Weight reduction chamber; 15. Threaded mounting hole; 2. Box cover; 21. Mounting through hole; 3. Filling piece; 36. Fixing hole; 4. First sealing ring; 5. Bolt; 6. Second sealing ring; 7. Temperature and humidity sensor. DETAILED DESCRIPTION

[0031] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0032] Please refer to Figure 2 , Figure 3 and Figure 4 , an efficient water activity testing equipment, comprising a temperature and humidity sensor 7, a box body 1 and a box cover 2. The box body 1 is cylindrical as a whole, and is made of aluminum alloy and has good thermal conductivity. The upper end face of the box body 1 is provided with a sample accommodating cavity 11 and a sensor accommodating cavity 12 which are separated. The sample accommodating cavity 11 is semicircular in shape and is used for placing a sample to be tested. The sensor accommodating cavity 12 includes an upper rectangular hole part 121 and a lower rectangular hole part 122, and the length and width of the upper rectangular hole part 121 are greater than those of the lower rectangular hole part 122. The upper rectangular hole part 121 and the lower rectangular hole part 122 are used for accommodating the head and the rod part of the temperature and humidity sensor 7 respectively. The box body 1 with the sample accommodating cavity 11 and the sensor accommodating cavity 12 is made of an aluminum alloy metal block through mechanical processing and electrochemical corrosion, and the box body 1 is an integral structure to ensure the sealing performance of the sample accommodating cavity 11 and the sensor accommodating cavity 12 at the upper port and to ensure good heat transfer effect, so that the temperature can be quickly raised to a specified temperature. The box cover 2 is disc-shaped as a whole, and is made of aluminum alloy and has good thermal conductivity. The diameter of the box cover 2 is the same as that of the box body 1.

[0033] Please refer to Figure 2 , Figure 3 and Figure 5 , the upper end face of the box body 1 is provided with a first annular groove 13, and the sample accommodating cavity 11 and the sensor accommodating cavity 12 are located in the first annular groove 13. The first annular groove 13 is a circular annular groove, and the first annular groove 13 is arranged on the common central axis of the box body 1. The upper end face of the box body 1 is uniformly provided with four threaded mounting holes 15 along the circumferential direction thereof, and each threaded mounting hole 15 is located outside the first annular groove 13. The box cover 2 is provided with mounting through holes 21 corresponding to each threaded mounting hole 15, and the rod part of the bolt 5 passes through the mounting through hole 21 and is screwed into the threaded mounting hole 15. The first annular groove 13 is provided with a first sealing ring 4, and the box cover 2 and the box body 1 are connected by a plurality of bolts 5. After the bolts 5 are tightened, the first sealing ring 4 is compressed, and there is a gap between the box body 1 and the box cover 2. The gap is kept below 0.5mm.

[0034] Please refer to Figure 2The temperature and humidity sensor 7 is arranged at the position corresponding to the sensor accommodating cavity 12 of the box cover 2, and a sealing structure is arranged between the temperature and humidity sensor 7 and the box cover 2. The box cover 2 is provided with a hole for mounting the head of the temperature and humidity sensor 7, and the sealing structure between the temperature and humidity sensor 7 and the box cover 2 comprises a second annular groove arranged on the hole wall of the hole and a second sealing ring 6 arranged in the second annular groove.

[0035] Please refer to Figure 2 , Figure 4 and Figure 6 , and further comprising a filling sheet 3, the shape of the filling sheet 3 is matched with the shape of the sample accommodating cavity 11, and the filling sheet 3 is also a semicircle, the size of the filling sheet 3 is slightly smaller than the size of the sample accommodating cavity 11, so that the filling sheet 3 can be put into the sample accommodating cavity 11 and taken out of the sample accommodating cavity 11, and too much sample to be measured cannot enter the gap between the filling sheet 3 and the cavity wall of the sample accommodating cavity 11. The filling sheet 3 is made of aluminum alloy and has good heat transfer effect. The filling sheet 3 can be used to adjust the use amount of the sample to be measured. The ratio of the sample space to the sensor space needs to be kept above a certain ratio, so as to be considered to accurately measure the water activity of the sample. The calculation process is obtained under the limit condition (high temperature and extremely low water activity), and for most samples to be measured, the use amount of the sample can be appropriately reduced to accurately measure the water activity of the sample, and the speed is faster.

[0036] Please refer to Figure 2 and Figure 3 , the lower end of the sample accommodating cavity 11 is provided with a weight reduction cavity 14, the lower end of the weight reduction cavity 14 is open, and the weight reduction cavity 14 is arranged on the lower end surface of the box body 1, and the weight reduction cavity 14 can be made by machining and electrochemical corrosion. By arranging the weight reduction cavity 14, the weight of the whole device can be reduced, and the portability of the device is improved. Secondly, since the temperature and humidity sensor 7 has a certain height, the height of the sample accommodating cavity 11 can be reduced by arranging the weight reduction cavity 14, the use amount of the filling sheet 3 can be reduced during testing, and the operation can be simplified, and the heat transfer effect can be effectively guaranteed.

[0037] The working principle of the utility model: the utility model separates the sample accommodating cavity 11 and the sensor accommodating cavity 12, effectively reduces the headspace, shortens the time for the sample to be measured and the headspace to reach equilibrium, improves the test efficiency, and reduces the test time. Taking egg powder with a water activity (25 DEG C) of 0.529 as an example, the temperature is raised from 30 DEG C to 90 DEG C and reaches equilibrium at 90 DEG C. The traditional test equipment needs 83 min, and the utility model only needs 30 min.

[0038] As shown in Figure 7 , taking egg white powder, egg powder and egg yolk powder with a water activity (25 DEG C) of 0.529 as examples, the change of the water activity of the samples at 25-75 DEG C is tested, and each group of tests is repeated three times. From the test results shown in Table 1, it can be seen that the water activity of the samples at 25 DEG C is 0.529, and the water activity of the samples at 75 DEG C is 0.527.Figure 7 It can be known that the error bar of the utility model is less than the conventional testing equipment in almost all tests, so the utility model also has the advantage of higher testing precision.

[0039] In addition, compared with manufacturing a "inverted T" type box to reduce the sensor accommodating cavity 12, the process manufacturing difficulty of the utility model is very low. Because in order to ensure good sealing, the testing equipment is integrally formed rather than welded, the processing difficulty of the "inverted T" type box is relatively large, and the waste of raw materials is also large, so the utility model also has the advantage of low manufacturing difficulty. The upper rectangular hole part 121 and the lower rectangular hole part 122 of the utility model are respectively matched with the head part and the rod part of the temperature and humidity sensor 7, so that the effect of further reducing the headspace is achieved.

[0040] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. An efficient water activity testing device, comprising a temperature and humidity sensor (7), characterized in that: The invention also comprises a box body (1) and a box cover (2), wherein the upper end surface of the box body (1) is provided with a sample accommodating cavity (11) and a sensor accommodating cavity (12) which are separated from each other, and a first annular groove (13) is provided on the upper end surface of the box body (1), wherein the sample accommodating cavity (11) and the sensor accommodating cavity (12) are both located in the first annular groove (13), and a first sealing ring (4) is provided in the first annular groove (13), and the box cover (2) and the box body (1) are connected by a plurality of bolts (5), and after tightening the bolts (5), the first sealing ring (4) is compressed, and a certain gap is provided between the box body (1) and the box cover (2); the temperature and humidity sensor (7) is provided at a position of the box cover (2) corresponding to the sensor accommodating cavity (12), and a sealing structure is provided between the temperature and humidity sensor (7) and the box cover (2); and the box cover (2) is provided with a hole for mounting the head of the temperature and humidity sensor (7).

2. The efficient water activity testing device according to claim 1, characterized in that: The sensor accommodating cavity (12) comprises an upper rectangular hole portion (121) and a lower rectangular hole portion (122), wherein the length and width of the upper rectangular hole portion (121) are respectively greater than the length and width of the lower rectangular hole portion (122), and the upper rectangular hole portion (121) and the lower rectangular hole portion (122) are respectively used to accommodate the head portion and the rod portion of the temperature and humidity sensor (7).

3. The efficient water activity testing device according to claim 1, characterized in that: The box body (1) is cylindrical in shape as a whole, is made of aluminum alloy, and is an integrally formed structure.

4. The efficient water activity testing device according to claim 3, characterized in that: The box cover (2) is disc-shaped as a whole, and the box body and box cover (2) are made of aluminum alloy. The box cover (2) and the box body (1) have the same diameter.

5. The efficient water activity testing device according to claim 3, characterized in that: The first annular groove (13) is a circular annular groove, and the first annular groove (13) and the box body (1) are arranged on the same central axis.

6. The efficient water activity testing device according to claim 5, characterized in that: The upper end surface of the box body (1) is evenly provided with at least four threaded mounting holes (15) along its circumferential direction, and each threaded mounting hole (15) is located outside the first annular groove (13). The box cover (2) is provided with mounting through holes (21) corresponding to each threaded mounting hole (15). The rod of the bolt (5) passes through the mounting through holes (21) and is screwed into the threaded mounting hole (15).

7. The efficient water activity testing device according to claim 1, characterized in that: A weight-reducing cavity (14) is provided below the sample accommodating cavity (11), and the lower end of the weight-reducing cavity (14) is open.

8. The efficient water activity testing device according to claim 1, characterized in that: In addition, a filling piece (3) is included. The shape of the filling piece (3) is adapted to the shape of the sample accommodating cavity (11). The filling piece (3) can be placed in the sample accommodating cavity (11) and can also be taken out of the sample accommodating cavity (11).

9. The efficient water activity testing device according to claim 8, characterized in that: The filling piece (3) is made of an aluminum alloy material, and the filling piece (3) and the sample accommodating cavity (11) are shaped like a semicircle.

10. The efficient water activity testing device according to claim 1, characterized in that: A second annular groove is provided on the wall of the hole for mounting the head of the temperature and humidity sensor (7), and a second sealing ring (6) is provided in the second annular groove.

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