CN112858582B - Electrical measurement sample rod for piston type pressure bag - Google Patents

Abstract

The invention discloses an electrical measurement sample rod for a piston type pressure bag, which comprises a connecting pipe fixedly connected with the pressure bag, wherein one end of the connecting pipe, which is far away from the pressure bag, is fixedly connected with a test switching part, and the test switching part is connected with an adjusting part; the test switching part comprises an adapter, and a connecting seat and an external connector are arranged on the adapter; the adjusting part comprises a sliding sleeve connected with the connecting seat; the connecting pipe comprises a hollow pipe and a lead arranged along the axial direction of the hollow pipe, and two ends of the lead are respectively communicated with the pressure bag and the external connector. And the air tightness of the sample rod is very good.

Description

An electrical measurement sample rod for a piston pressure pack

technical field

The invention relates to the field of electrical measurement, in particular to an electrical measurement sample rod used for a piston-type pressure pack.

Background technique

The piston-type pressure pack is a cylindrical structure with two ends fixed by screws. The sample is sealed in a Teflon tube filled with high-pressure oil, and then placed in the cylinder. One end leads to a belt line and is fixed with screws; the other end, The Teflon tube is pressurized by the pressure transmission method of screwing the screw, and the high pressure oil is squeezed to obtain the pressure. The more the screw is screwed in, the greater the pressure is obtained. In this way, the length of the piston pressure pack is different under different pressures. Therefore, when the comprehensive physical property measurement system (PPMS) designed by Quantum Design Company performs electrical measurement under pressure, there is a problem. The length of the pressure pack is different, and the length of the sample rod is also changing. As a result, there are two main problems in the measurement: the problem of thermal connection and the vacuum degree of the sample chamber. The main reason is that the length of the sample rod cannot be fixed, and the initial length of the sample rod must be the longest. At this time, the normal heat exchange between the sample cavity and the sample rod can be ensured. However, as the pressure increases, the screw of the pressure pack is continuously screwed in, and the rod The overall length is getting shorter and shorter, so it is difficult for the subsequent pressure points to ensure the normal heat exchange, causing great measurement errors. The latter uses the general sealing method, which will cause air leakage when encountering this special situation, which will cause the temperature of the sample chamber to not drop. After long-term operation, the entry of water vapor in the air will cause the sample chamber to freeze, and the cold head of the refrigerator will gradually deteriorate. At the same time, it will aggravate the deterioration of the heat exchange, which will lead to the damage of the instrument and the failure of the measurement. At present, Quantum Design's solution is to use a method without a sample rod. The piston pressure pack is directly clamped by a clamp, placed in the sample cavity, and measured using the built-in measurement system that comes with PPMS. After the measurement is completed, the clamp is used to Piston pressure packs out. There are two main problems. Second, the weight of the piston pressure pack itself is very heavy compared to the general sample holder. The PPMS sample cavity can just put down the pressure pack, and the operating space is very limited, which requires the clamping force of the fixture. It is very high, and the pressure pack slips in the sample cavity often due to careless operation, which is extremely harmful to the pins of the built-in measurement in the PPMS sample cavity. , there is a great risk. Second, the built-in measurement system measures the sample in the pressure pack. It can only measure one sample at a time. The measurement efficiency is lower than that of the external system. Due to the limitation of the built-in measurement system, users sometimes need some special measurement requirements, and PPMS cannot meet these requirements. Now colleges and research institutes are very nervous about measuring machines, which is undoubtedly a big disadvantage.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an electrical measurement sample rod for a piston-type pressure pack, so as to solve the problems raised in the above-mentioned background art.

To achieve the above object, the present invention provides the following technical solutions:

An electrical measurement sample rod for a piston-type pressure pack, comprising a connecting pipe fixedly connected with the pressure pack, and a test adapter part is fixedly connected with one end of the connecting pipe away from the pressure pack, and the test adapter part is connected with the adjustment part;

The test adapter includes an adapter, and the adapter is provided with a connection seat and an external connector;

the adjusting part includes a sliding sleeve connected with the connecting seat;

The connecting tube includes a hollow tube and a wire arranged along the axis of the hollow tube, and the two ends of the wire are respectively communicated with the pressure pack and the external joint.

As a further solution of the present invention: the adapter has a hollow cube structure, one side of the adapter is provided with a square opening, the square opening of the adapter is sealed and connected to the connector, and the external joint is fixedly connected to the connector outside.

As a further solution of the present invention: the connecting seat is a hollow cylinder, the connecting seat is fixedly connected to the hollow tube, and the connecting seat is used for avoiding holes for passing wires when in use.

As a further solution of the present invention: the external connector is a Lemo male connector, and a measuring instrument is connected to the external connector.

As a further solution of the present invention: one end of the sliding sleeve close to the adapter is provided with a sleeve head, one end of the connecting seat close to the sliding sleeve is fixedly connected with a gasket, the lower end of the gasket is provided with a washer, and the The spacer and the washer are located at the upper end of the sliding sleeve, and the spacer and the washer are located in the sleeve head.

As a further solution of the present invention, the hollow tube is provided with at least one heat-resisting sheet along the axial direction, and at least one ventilation hole is arranged on the hollow tube.

As a further solution of the present invention, the hollow tube is fixedly connected to the pressure pack through a connecting portion.

As a further solution of the present invention, the connecting portion includes a coupling fixedly connected with the hollow tube, and the coupling and the pressure pack are fixedly connected through a connecting head.

As a further solution of the present invention, a heat conducting ring is wrapped on the outside of the connector, a thermometer is provided on one side of the connector, and the thermometer communicates with the wire.

As a further solution of the present invention, the pressure pack includes a sample chamber, a compression bolt is threadedly connected to the lower end of the sample chamber, and a sample base holder is fixedly connected to the lower end of the compression bolt.

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention provides a sample rod whose length can be adjusted, so when the length of the pressure pack changes, the upper and lower positions of the test adapter and the sliding sleeve can be adjusted to ensure the sample base at the bottom of the sample rod and the bottom of the inner wall of the measurement system. The ends are in close contact to ensure good thermal conductivity, which in turn makes the measurement accuracy and efficiency high. And the air tightness of the sample rod is very good, it can reach 182mbar at 2K, and the sample rod can reach the lowest temperature of the system at low temperature 1.6K.

2. In the present invention, by setting the wire to connect with the pressure pack, the measuring device is externally placed, and an external measuring system is used. The measuring means are various, and several samples can be measured at the same time, and the sample rod has no risk of damaging the instrument.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the sample rod of the present embodiment;

2 is a cross-sectional view of the sample rod of the present embodiment;

3 is a schematic structural diagram of the sample rod adapter of the present embodiment;

FIG. 4 is a schematic structural diagram of the test part of the sample rod of the present embodiment;

FIG. 5 is a time-air pressure change diagram when the sample chamber is cooled in the present embodiment;

FIG. 6 is a time-temperature change diagram when the sample chamber is cooled in the present embodiment.

In the picture: 1-Test adapter, 11-Adapter, 12-Connector, 13-Connector, 14-External connector, 2-Adjustment, 21-Sliding sleeve, 22-Gasket, 23-Washer, 24-Sleeve head, 3-Connecting tube, 31-Wire, 32-Heat shield, 33-Hollow tube, 4-Connecting part, 41-Coupling, 42-Connecting head, 43-Conducting ring, 44-Thermometer , 5-pressure pack, 51-sample cavity, 52-pressure screw, 6-sample base holder.

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.

Please refer to FIGS. 1-5. In an embodiment of the present invention, an electrical measurement sample rod for a piston-type pressure pack includes a connecting pipe 3 fixedly connected to the pressure pack 5, and one end of the connecting pipe 3 away from the pressure pack 5 is fixedly connected There is a test adapter part 1, and an adjustment part 2 is connected to the test adapter part 1. The test adapter part 1 includes an adapter 11, a connector 12, a connecting seat 13, and an external joint 14. The adjustment part 2 includes a sliding sleeve 21, Gasket 22 , washer 23 , sleeve head 24 , connecting tube 3 includes wire 31 , heat-blocking sheet 32 , and hollow tube 33 , and connecting portion 4 includes coupling 41 , connecting head 42 , heat-conducting ring 43 , and thermometer 44 .

The test adapter 1 includes an adapter 11. The adapter 11 is provided with a connecting seat 13 and an external joint 14. The adapter 11 has a hollow cube structure. One side of the adapter 11 is provided with a square opening. The square opening of the adapter is sealed and connected with The connector 12, the external joint 14 is fixedly connected to the outside of the connector 12, the connecting seat 13 is a hollow cylinder, the connecting seat 13 is fixedly connected with the hollow tube 33, and the connecting seat 13 is used for the escape hole for the wire 31 to pass through, The external connector 14 is a Lemo male head, and the external connector 14 is connected with a measuring instrument.

The adjusting part 2 includes a sliding sleeve 21 connected with the connecting base 13 , the end of the sliding sleeve 21 close to the adapter 11 is provided with a sleeve head 24 , and one end of the connecting base 13 close to the sliding sleeve 21 is fixedly connected with a gasket 22 . The lower end of the sheet 22 is provided with a washer 23, the washer 22 and the washer 23 are located at the upper end of the sliding sleeve 21, the washer 22 and the washer 23 are located in the sleeve head 24, and the sliding sleeve 21 can slide relative to the connecting seat 13 within a certain distance up and down, When the sleeve head 24 is tightened, the gasket 22 squeezes the rubber gasket 23 to seal the sliding gap between the connecting seat 13 and the sliding sleeve 21 to obtain a vacuum. At this time, the sliding sleeve and the connecting seat can slide with each other, and at a temperature of 1.66K, the air pressure in the cavity can reach 182mbar, achieving good sealing.

The connecting tube 3 includes a hollow tube 33 and a wire 31 arranged along the axis of the hollow tube 33. Both ends of the wire 31 are connected to the pressure pack 5 and the external connector 14 respectively. The wire is a braided copper wire, and the two wires are twisted. On the winding hollow tube, the hollow tube 33 is installed with at least three heat-blocking sheets 32 along the axis direction, and at least one ventilation hole is arranged on the hollow tube 33. In this embodiment, the hollow tube is made of stainless steel, which has no poor magnetic thermal conductivity. Easy to heat sink. In addition, three small holes are opened on the hollow tube, so that when vacuuming, the air in the rod is not evacuated, which affects the cooling of the sample rod.

The hollow tube 33 is fixedly connected to the pressure pack 5 through the connecting portion 4, and the connecting portion 4 includes a coupling 41 that is fixedly connected to the hollow tube 33. The coupling 41 and the pressure pack 5 are fixedly connected through a connecting head 42. The connecting head 42 A heat-conducting ring 43 is wrapped on the outside, and the heat-conducting ring is in contact with the wall of the sample cavity to speed up the cooling of the sample in the pressure pack. The connector 42 is provided with a notch, and a thermometer 44 is arranged in the notch. The temperature reflected by the thermometer is taken as the temperature on the sample.

The pressure pack 5 includes a sample cavity 51, the lower end of the sample cavity 51 is screwed with a pressure bolt 52, the lower end of the pressure bolt 52 is fixedly connected with a sample base holder 6, and a sample holder base in the cavity of a special comprehensive physical property measurement system is fixed behind the pressure pack , This base matches the notch for sample measurement in the sample chamber. When the sample rod is inserted, the two match to ensure that the sample rod is in contact with the base in the cavity, which is convenient for thermal connection, and the sample holder base is connected with All parts are made of oxygen-free copper, which has good thermal conductivity and no magnetism; the coupling is made of stainless steel, which has poor thermal conductivity and no magnetism, which is convenient for heat sinking.

When the pressure of the piston pressure pack is different, the length of the pressure pack is also different. When the sample rod is inserted into the cavity of the comprehensive physical property measurement system, the sample rod is in contact with the base in the sample cavity. When the temperature is lowered, due to thermal expansion and contraction, the sample rod will It is disconnected from the measurement notch of the chamber base, resulting in the sample rod not directly contacting the chamber base when the temperature is lowered to the lowest temperature.

The test cable adapter of this embodiment is combined with its matching sliding sleeve, gasket, gasket, and sleeve head. When in use, the sample to be tested is placed in the sample cavity of the pressure pack 5, and then the The sample rod is inserted into the sample cavity. At this time, the sample base holder at the lower end of the pressure pack 5 is matched with the notch inside the sample cavity of the comprehensive physical property measurement system, thereby ensuring a tight connection and improving thermal connection. In addition, when the sample rod is inserted When entering the sample chamber, the sliding sleeve 21 is connected to the vacuum flange on the sample chamber. At this time, the sliding sleeve 21 and its sleeve head 24, the gasket 22 and the rubber gasket 23 are all fixed. When the normal sample chamber is cooled down, the air pressure in the chamber is much lower than the atmospheric pressure. Under the action of atmospheric pressure, the test adapter will always be pressed down by the atmospheric pressure, and then the connecting seat 13 will slide down relative to the sliding sleeve to make up for the length of the piston pressure pack. Changes and the influence of thermal expansion and contraction, the position of the test adapter and the sliding sleeve can be adjusted up and down to make up for the inconsistency of the length of the sample rod. Through the cooperation between the sliding sleeve and the test adapter, when the temperature drops, the air pressure drops, and the atmospheric pressure is used to directly press the sample rod tightly against the sample measurement notch in the cavity to ensure a firm thermal connection. At the same time, the heat conduction ring on the connector is in contact with the wall of the sample chamber. Since there is a constant temperature zone at the bottom of the PPMS sample chamber, the upper and lower parts of the piston pressure pack are in contact with the sample chamber, which can better conduct heat conduction and reduce the temperature difference between the upper and lower pressure packs. Improve measurement accuracy.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

1. The electrical measurement sample rod for the piston type pressure bag is characterized by comprising a connecting pipe (3) fixedly connected with the pressure bag (5), wherein one end, far away from the pressure bag (5), of the connecting pipe (3) is fixedly connected with a test switching part (1), and the test switching part (1) is connected with an adjusting part (2);

the test switching part (1) comprises a switching head (11), and a connecting seat (13) and an external connector (14) are arranged on the switching head (11);

the adjusting part (2) comprises a sliding sleeve (21) connected with the connecting seat (13), a sleeve head (24) is arranged at one end, close to the adapter (11), of the sliding sleeve (21), a gasket (22) is fixedly connected to one end, close to the sliding sleeve (21), of the connecting seat (13), a gasket (23) is arranged at the lower end of the gasket (22), the gasket (22) and the gasket (23) are located at the upper end of the sliding sleeve (21), and the gasket (22) and the gasket (23) are located in the sleeve head (24);

the connecting pipe (3) comprises a hollow pipe (33) and a lead (31) arranged along the axial direction of the hollow pipe (33), and two ends of the lead (31) are respectively communicated with the pressure packet (5) and the external connector (14).

2. The electrical measurement sample rod for the piston type pressure bag as claimed in claim 1, wherein the adapter (11) is a hollow square structure, a square opening is formed in one side of the adapter (11), a connector (12) is hermetically connected in the square opening of the adapter, and the external connector (14) is fixedly connected to the outer side of the connector (12).

3. An electrical measuring sample rod for a piston type pressure bag according to claim 1, characterized in that the connecting base (13) is a hollow cylinder, the connecting base (13) is fixedly connected with the hollow tube (33), and an avoiding hole for a lead wire (31) to pass through is arranged on the connecting base (13) when in use.

4. An electrical measuring sample rod for a piston-type pressure bag according to claim 1, characterized in that the external connector (14) is a Raymond head, the external connector (14) being connected to a measuring instrument.

5. An electrical measurement sample rod for a piston type pressure bag according to claim 1, characterized in that the hollow tube (33) is provided with at least three heat resistant sheets (32) along the axial direction, and the hollow tube (33) is provided with at least one vent hole.

6. Electrical measuring sample rod for piston-type pressure packs according to claim 1, characterised in that the hollow tube (33) is fixedly connected with the pressure pack (5) by means of a connection (4).

7. Electrical measuring sample rod for piston type pressure bag according to claim 6 characterized in that the connection part (4) comprises a coupling (41) fixedly connected with a hollow tube (33), the coupling (41) and the pressure bag (5) are fixedly connected through a connector (42).

8. An electrical measuring sample rod for a piston type pressure bag according to claim 7, characterized in that the connector (42) is externally wrapped with a heat conducting ring (43), a thermometer (44) is arranged on one side of the connector (42), and the thermometer (44) is communicated with the lead (31).

9. An electrical measurement sample rod for a piston type pressure bag according to claim 1, characterized in that the pressure bag (5) comprises a sample cavity (51), a pressurizing bolt (52) is connected with the lower end of the sample cavity (51) in a threaded manner, and a sample bottom holder (6) is fixedly connected with the lower end of the pressurizing bolt (52).

Images