Handheld calibration instrument and method for manufacturing the same

Abstract

An embodiment of the present invention discloses a handheld calibration instrument and a manufacturing method thereof, including: a lower housing provided with a receiving cavity having an opening; a first circuit board disposed in the lower housing, on which at least two first plug-in ends are provided; an insertion component that can be inserted into the receiving cavity in a matching manner, the insertion component includes a cover plate and at least one second circuit board, and different combinations of at least one second circuit board achieve different functions or function combinations. Each second circuit board has a first end and a second end. The first end is provided with a second plug-in end that is matched and inserted with the first plug-in end, and the second end is provided with a wire connection port for accessing a to-be-tested electrical signal or outputting an electrical signal. The cover plate is provided with a hole corresponding to the wire connection port. After the insertion component is inserted into the receiving cavity from the opening, the second plug-in end of each second circuit board is inserted into one of the at least two first plug-in ends to establish an electrical connection with the first circuit board, and the cover plate plugs the opening and is hermetically sealed with the lower housing as a whole.

Description

Technical Field

[0001] The present invention relates to the field of instruments and meters, and particularly to a handheld calibration instrument and a manufacturing method thereof. Background Art

[0002] Among handheld instruments, process calibration instruments are mainly used for high-precision measurement, detection, and calibration of temperature and pressure industrial instruments and meters. For example, in on-site commissioning of temperature and pressure industrial instruments and meters and in the production process of instrument factories, process calibration instruments can achieve high-precision measurement and output of signals. Most process calibration instruments are divided into temperature type and pressure type. The pressure type is a separate product, and the temperature type is a separate product, with relatively fixed functions.

[0003] In some application scenarios, users may need to measure multiple parameters simultaneously. For example, measure temperature and pressure simultaneously, or measure thermal resistance and thermocouple simultaneously. If there is no corresponding single device to achieve multiple parameter measurements, users need to operate multiple products to achieve multiple parameter measurements, which will bring inconvenience to users. In other application scenarios, users may only need some of the functions. For example, users only need the single function of pressure measurement. Configuring all functions or a combination of multiple functions is likely to cause waste of resources. Most existing calibrators have relatively fixed functions. If they can be combined according to requirements, the user experience will be greatly improved. Summary of the Invention

[0004] Embodiments of the present invention provide a handheld instrument and a manufacturing method thereof, which can perform function combination according to functional requirements.

[0005] Embodiments of the present invention adopt the following technical solutions:

[0006] A handheld calibration instrument includes:

[0007] A lower housing, the lower housing is provided with a receiving cavity having an opening;

[0008] A first circuit board, the first circuit board is disposed within the lower housing, and at least two first plug-in ends are provided on the first circuit board;

[0009] An insertion component, the insertion component can be inserted into the receiving cavity in a matching manner. The insertion component includes a cover plate and at least one second circuit board. Different combinations of the at least one second circuit board achieve different functions or function combinations. Each second circuit board in the at least one second circuit board has a first end and a second end. The first end is provided with a second plug-in end that is inserted into and matched with the first plug-in end, and the second end is provided with a wire connection port;

[0010] After the insertion component is inserted into the accommodation cavity from the opening, the second insertion end of each second circuit board in the at least one second circuit board is inserted into one of the at least two first insertion ends to establish electrical connection with the first circuit board, and the cover plate seals the opening and is hermetically enclosed with the lower housing as a whole.

[0011] A method for manufacturing a handheld calibration instrument, comprising:

[0012] Constructing a lower housing with an accommodation cavity having an opening;

[0013] Arranging a first circuit board in the lower housing, and arranging at least two first insertion ends on the first circuit board;

[0014] Constructing an insertion component that can be inserted into the accommodation cavity in a matching manner, the insertion component including a cover plate and at least one second circuit board, different combinations of the at least one second circuit board realizing different functions or function combinations, each second circuit board in the at least one second circuit board having a first end and a second end, the first end being provided with a second insertion end that is matched and inserted with the first insertion end, and the second end being provided with a wire connection port for accessing a to-be-tested electrical signal or outputting an electrical signal, and the cover plate being provided with a hole corresponding to the wire connection port;

[0015] Inserting the insertion component into the accommodation cavity from the opening, such that the second insertion end of each second circuit board in the at least one second circuit board is inserted into one of the at least two first insertion ends to establish electrical connection with the first circuit board, and the cover plate seals the opening and is hermetically enclosed with the lower housing as a whole.

[0016] Based on the above technical solution, a handheld calibration instrument and its manufacturing method, arranging a circuit board with an insertion interface in the lower housing and arranging an accommodation cavity having an opening, arranging an insertion component that realizes different functions or function combinations with different circuit board combinations, inserting the insertion component including different circuit board combinations into the accommodation cavity of the lower housing, and inserting the insertion ends of the circuit boards on the insertion component into the insertion ends of the circuit board in the accommodation cavity, so as to select different circuit boards to construct the insertion component according to requirements, and after the constructed insertion component including different circuit boards is inserted into the lower housing, a handheld instrument with different functions is formed.

[0017] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. Description of the Drawings

[0018] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments that conform to the present invention, and are used together with the specification to explain the principles of the present invention.

[0019] Figure 1aSchematic diagram of the lower housing and accommodation cavity structure of the handheld inspection instrument provided by the embodiment of the present invention;

[0020] Figure 1b Schematic diagram of the structure of the handheld inspection instrument provided by the embodiment of the present invention;

[0021] Figure 2a One of the schematic diagrams of the circuit board insertion of the handheld inspection instrument provided by the embodiment of the present invention;

[0022] Figure 2b Another schematic diagram of the circuit board insertion of the handheld inspection instrument provided by the embodiment of the present invention;

[0023] Figure 2c Another schematic diagram of the circuit board insertion of the handheld inspection instrument provided by the embodiment of the present invention;

[0024] Figure 3a Schematic diagram of various adapter insertion modules of the handheld inspection instrument provided by the embodiment of the present invention;

[0025] Figure 3b Schematic diagram of the structure of the insertion module of the handheld inspection instrument provided by the embodiment of the present invention;

[0026] Figure 3c Schematic diagram of the cover plate structure of the insertion module of the handheld inspection instrument provided by the embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the module structure of the handheld inspection instrument provided by the embodiment of the present invention.

[0028] Reference numerals:

[0029] 100, lower housing, 110, accommodation cavity, 111, guide groove, 120, screen, 130, partition board, 140, battery cavity;

[0030] 200, first circuit board main board module, 210, first insertion end, 220, signal processor, 230, connection part;

[0031] 300, insertion component, electrical measurement module, 310, cover plate, 311, hole, 312, positioning groove, 320, second circuit board, 321, second insertion end, 322, wire connection port. Detailed implementation manners

[0032] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of apparatuses and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0033] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application and do not limit the scope of the present application in any way; in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another feature and do not represent any limitation on the features.

[0034] In this specification, the general working state of the handheld calibration instrument is used to determine each direction. The direction in which the display unit faces (in the general working state, the display unit faces the user) is defined as the front direction. Correspondingly, the left, right, up, down, and back directions can be determined; it should be noted that this description of the direction is only a relative direction for the convenience of understanding and does not constitute a limitation on the actual technical solution.

[0035] In this specification, two circuit boards being parallel means that the two circuit boards are not in the same plane and the planes where the two circuit boards are located are parallel to each other; two circuit boards being coplanar and parallel means that the two circuit boards are in the same plane; two circuit boards intersecting means that there is an angle greater than 0 degrees and less than 180 degrees between the two circuit boards.

[0036] Embodiment 1

[0037] This embodiment provides a handheld calibration instrument, which is set to have a shape and weight suitable for being held by hand, and is convenient for users to hold and operate in scenarios suitable for handheld operation, such as Figure 1a 、 Figure 1b As shown, the handheld calibration instrument includes: a lower housing 100, a first circuit board 200, and an insertion component 300.

[0038] As Figure 1a shown, the lower housing 100 is provided with a receiving cavity 110 having an opening ( Figure 1a the dashed box in), most of the receiving cavity 110 is wrapped by the lower housing 100, the opening of the receiving cavity 110 is provided above the lower housing 100, and the opening of the receiving cavity 110 is visible above the lower housing 100 in the non-inserted state of the insertion component 300.

[0039] As Figure 1bAs shown, the first circuit board 200 is disposed within the lower housing 100, and at least two first plug-in terminals 210 are provided on the first circuit board 200. It should be understood that the positions of the first plug-in terminals 210 can be set as needed, preferably at positions convenient for plugging into the second circuit board 320.

[0040] As Figure 1b , Figure 2a , Figure 3b , Figure 3c shown, the insertion component 300 can be inserted into the accommodation cavity 110 in a matching manner. The insertion component 300 includes a cover plate 310 and at least one second circuit board 320. Each second circuit board 320 can be inserted into the accommodation cavity 110 in a matching manner and plugged into the first circuit board 200 to form an integral body. Different combinations of at least one second circuit board 320 among the at least one second circuit board 320 achieve different functions or function combinations, so as to configure different second circuit boards 320 according to different application scenarios and function requirements. Each second circuit board 320 among the at least one second circuit board 320 has a first end and a second end. The first end is the connection end with the first circuit board 200. A second plug-in terminal 321 that is matched and inserted with the first plug-in terminal 210 is provided at the first end. A wire connection port 322 is provided at the second end. The wire connection port 322 can be provided directly above the second end or on one side of the second end. The wire connection port 322 is used to establish an electrical connection with an externally inserted electrical connection plug. The cover plate 310 is provided with a hole 311 corresponding to the wire connection port 322, so that the electrical connection plug can be inserted into the wire connection port 322 outside the cover plate 310. In this embodiment, for the convenience of inserting the electrical connection plug into the wire connection port 332, a matching wire connection port 332 can be set according to the signal of the inserted electrical connection plug. The wire connection port 322 is used for the handheld inspection instrument to establish a connection with the device under measurement, including but not limited to accessing the electrical signal to be measured, outputting an electrical signal, and simulating temperature analog output. The wire connection port 322 is set to an interface shape adapted to the connection line of the device under measurement, including but not limited to a cylindrical deep hole, a thermocouple TC double jack, and a PT100 thermal resistance circular jack.

[0041] As Figure 3a shown, the insertion component 300 can be different insertion components 300a, 300b, 300c, 300d formed by combining a variety of second circuit boards 320. Different insertion components 300a, 300b, 300c, 300d can all be inserted into the accommodation cavity 110 in a matching manner and sealed with the lower housing 100 to form a combined handheld calibration instrument.

[0042] After the insertion component 300 is inserted into the accommodation cavity 110 from the opening, the second insertion end 331 of each second circuit board 320 in at least one second circuit board 320 is inserted into one of at least two first insertion ends 210 to establish an electrical connection with the first circuit board 200. The cover plate 310 seals the opening of the accommodation cavity 110 and is hermetically sealed with the lower housing 100 as a whole. In different embodiments, to facilitate the cover plate 310 to seal the opening of the accommodation cavity 110, the contact position between the opening of the accommodation cavity 110 and the cover plate 310 can be set as a matching sealing and buckling structure. The sealing and buckling structure can be set such that the cover plate 310 is provided with an extended edge, and a groove matching the edge is provided at the opening of the accommodation cavity 110, and the extended edge of the cover plate 310 is closely attached and sealed with the groove of the accommodation cavity 110. Screwdriver mounting holes can also be provided on the cover plate 310, and a screw tightening structure is correspondingly provided on the lower housing 100. After the insertion component 300 is inserted into the accommodation cavity 110, the insertion component 300 is fixed to the lower housing 100 with screws.

[0043] It should be understood that each second circuit board 320 can be connected to the corresponding first insertion end 210 provided on the first circuit board 200. Preferably, multiple first insertion ends 210 are interfaces of the same specification. Of course, multiple first insertion ends 210 can be insertion interfaces of the same specification or different specifications, which is not limited in this embodiment. There are multiple insertion methods between the first insertion end 210 and the second insertion end 321. For example, the second insertion end 321 can be set as an insertion end and the first insertion end 210 can be set as a card slot end, or the second insertion end 321 can be set as a card slot end and the first insertion end 210 can be set as an insertion end, as long as the second insertion end 321 can be matched and inserted with the first insertion end 210, which is not limited in this embodiment.

[0044] Figure 1b After the shown insertion component 300 is inserted into the opening of the accommodation cavity 110, the insertion component 300 and the lower housing 100 are hermetically sealed as a whole to form a complete handheld calibration instrument that can be used.

[0045] Such as Figure 1b 、 Figure 2a 、 Figure 2cAs shown, in different embodiments, the second circuit board 320 may be one, two, three or more, so that combinations of the same or different second circuit boards 320 form insertion components 300 with different functions. The insertion component including a combination of different circuit boards 320 is inserted into the accommodation cavity 110 of the lower housing 100, and the second insertion end 321 of the second circuit board 320 is inserted and connected to the first insertion end 210 of the first circuit board 200 in the accommodation cavity, thereby realizing the selection of different second circuit boards 320 according to requirements to construct the insertion component 300. After the constructed insertion component 300 including different second circuit boards 320 is inserted and connected to the lower housing 100, a handheld inspection instrument with different functions is formed.

[0046] As Figure 2a shown, in some embodiments, the insertion component 300 includes at least two second circuit boards 320, and every two adjacent ones of the at least two second circuit boards 320 are spaced apart from each other. In different embodiments, the positions of the at least two second circuit boards 320 after being inserted and connected to the first circuit board 200 may be different. In one embodiment, at least one of the at least two second circuit boards 320 is parallel or coplanar with the first circuit board 200. As Figure 2a shown, the circuit board 320a is coplanar with the circuit board 200, and the circuit boards 320b and 320c are parallel to the circuit board 200. As Figure 2b shown, in another embodiment, at least two second circuit boards 320 intersect with the first circuit board 200.

[0047] In some embodiments, at least one of the at least two first insertion ends 210 on the insertion component 300 is disposed at one end of the first circuit board 200 close to the accommodation cavity 110 and is coplanar with the first circuit board 200, as shown in FIGS. 2a, Figure 2c shown, the first insertion end 210a is coplanar with the first circuit board 200. In some embodiments, as shown in FIGS. 2, Figure 2c shown, at least one of the at least two first insertion ends 210 is disposed at the connection portion 220 of the first circuit board. The connection portion 230 extends vertically from the side of the first circuit board 200, and the connection portion 230 is electrically connected to the first circuit board 200. In some embodiments, as Figure 2a 、 Figure 2c shown, at least one of the at least two first insertion ends 210 is disposed at one end of the first circuit board 200 close to the accommodation cavity 110 and is coplanar with the first circuit board 200, and at least one of the at least two first insertion ends 210 is disposed at the connection portion of the first circuit board 200. The connection portion 230 extends vertically from the side of the first circuit board 200, and the connection portion 230 is electrically connected to the first circuit board.

[0048] In some embodiments, as Figure 2cAs shown, at least one of one or more second circuit boards 320 provided on the insertion component 300 includes: an electrical signal measurement board 320a. The electrical signal measurement board 320a is combined with the first circuit board 200 to measure at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals. Specifically, the first circuit board 200 supplies power to the electrical signal measurement board 320a through a plug-in terminal, and sends a measurement instruction to the electrical signal measurement board 320a through the plug-in terminal, triggering the electrical signal measurement board 320a to execute the measurement instruction to implement the corresponding measurement function, and returning the measurement result to the first circuit board 200 through the plug-in terminal for the first circuit board 200 to display or process the measurement result.

[0049] In some embodiments, as Figure 2c shown, at least one of one or more second circuit boards 320 provided on the insertion component 300 includes: an electrical signal output board 320b. The electrical signal output board 320b is combined with the first circuit board 200 to output at least one of voltage, current, frequency, and pulse outputs. Specifically, the first circuit board 200 supplies power to the electrical signal output board 320b through a plug-in terminal, and sends an output instruction to the electrical signal output board 320b through the plug-in terminal, triggering the electrical signal output board 320b to execute the output instruction to implement the corresponding signal output.

[0050] In some embodiments, as Figure 2c shown, at least one of one or more second circuit boards 320 provided on the insertion component 300 includes: an integrated board 320c for temperature measurement and analog output. The integrated board 320c for temperature measurement and analog output is provided with a cold junction compensation circuit. The integrated board 320c for temperature measurement and analog output is combined with the first circuit board 200 to measure and analog output resistance temperature detector (RTD) and thermocouple (TC). Among them, the integrated board 320c for temperature measurement and analog output means that the functions of temperature measurement and analog output are integrated on a single circuit board. Specifically, the first circuit board 200 supplies power to the integrated board 320c for temperature measurement and analog output through a plug-in terminal, and sends a measurement and output instruction to the electrical signal output board through the plug-in terminal, triggering the integrated board 320c for temperature measurement and analog output to execute the measurement and output instruction to implement temperature measurement and analog output.

[0051] In some embodiments, as Figure 2cAs shown, at least one of one or more second circuit boards 320 provided on the insertion component 300 includes: a temperature measurement board 320d. The temperature measurement board 320d is combined with the first circuit board to implement the measurement of one or more resistance temperature detectors (RTDs) and / or thermocouples (TCs). Specifically, the first circuit board supplies power to the temperature measurement board 320d through the insertion terminal, and transmits a measurement instruction to the temperature measurement board 320d through the insertion terminal, triggering the temperature measurement board 320d to execute the measurement instruction for measurement, and returning the measurement result to the first circuit board 200 through the insertion terminal for the first circuit board 200 to display or process the measurement result. In different embodiments, the temperature measurement board 320d can be set to single-channel temperature measurement, dual-channel temperature measurement, or triple-channel and above temperature measurement. This embodiment does not make a limitation. This embodiment preferably sets the temperature measurement board 320d to a dual-channel resistance temperature detector (RTD) and a dual-channel thermocouple (TC) channel. When setting the number of RTD and TC channels, it can be adjusted according to different scenarios. Preferably, the RTD and TC channels are set in pairs.

[0052] In some embodiments, as Figure 2c As shown, at least one of one or more second circuit boards 320 provided on the insertion component 300 includes: a PT100 measurement template 320e. The PT100 measurement template 320e is combined with the first circuit board 200 to implement the measurement of one or more PT100 resistance temperature detectors. Specifically, the first circuit board 200 supplies power to the PT100 measurement template 320e through the insertion terminal, and sends a measurement instruction to the PT100 measurement template 320e through the insertion terminal, triggering the PT100 measurement template 320e to execute the measurement instruction to implement the corresponding measurement function, and returning the measurement result to the first circuit board 200 through the insertion terminal 210 for the first circuit board 200 to display or process the measurement result. In different embodiments, the PT100 measurement template 320e can be set to single-channel temperature measurement, dual-channel temperature measurement, or triple-channel and above temperature measurement. This embodiment does not make a limitation. This embodiment preferably sets the PT100 measurement template 320e to dual-channel. When setting the number of PT100 measurement channels of the PT100 measurement template 320e, it can be adjusted according to different scenarios. Preferably, it is set to dual-channel PT100 measurement.

[0053] In some embodiments, as Figure 2a 、 Figure 2cAs shown, three second circuit boards 320 are provided on the insertion component 300: an electrical signal measurement board 320a, an electrical signal output board 320b, and an integrated board 320c for temperature measurement and analog output. The electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output cooperate with each other to achieve process verification of parameters. Among them, the electrical signal measurement board 320a is combined with the first circuit board 200 to measure at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART. The electrical signal output board 320b is combined with the first circuit board to output at least one of the signals of voltage, current, frequency, and pulse output. The integrated board 320c for temperature measurement and analog output is provided with a cold junction compensation circuit, and the integrated board 320c for temperature measurement and analog output is combined with the first circuit board to achieve the measurement and analog output of the resistance temperature detector (RTD) and the thermocouple (TC). Specifically, according to different application scenarios, the electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output can work independently simultaneously or cooperate with each other. For example, during the electrical signal output process of the electrical signal output board 320a, the electrical signal measurement board 320b simultaneously measures the electrical signal, so as to realize the cooperation of multiple circuit boards working simultaneously to achieve more complex functions than a single circuit board, so as to adapt to different application scenarios.

[0054] In some embodiments, referring to Figure 2c As shown, one or more second circuit boards 320 are provided on the insertion component 300: an electrical signal measurement board 320a and a PT100 measurement template 320e. The electrical signal measurement board 320a and the PT100 measurement template 320e cooperate with each other to achieve pressure and temperature recording. The electrical signal measurement board 320a is combined with the first circuit board 200 to measure at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART. The PT100 measurement template 320e is combined with the first circuit board 200 to achieve the measurement of one or more PT100 resistance temperature detectors. Specifically, according to different application scenarios, the electrical signal measurement board and the PT100 measurement template 320e can work simultaneously or cooperate with each other. For example, during the measurement process of the electrical signal measurement board, the PT100 measurement template 320e simultaneously measures the PT100, so as to realize the cooperation of multiple circuit boards working simultaneously to achieve more complex functions than a single circuit board, so as to adapt to different application scenarios. Among them, the number of measurement channels of the PT100 measurement template can be set according to different scenarios, and it is preferably set to dual-channel PT100 measurement.

[0055] In some embodiments, as Figure 3b 、 Figure 3cAs shown, the cover plate 310 is provided with positioning grooves 311 corresponding to the number of the second circuit boards 320. Each positioning groove 311 includes a raised rib. The second end of each second circuit board 320 is limited within its corresponding positioning groove. Among them, the raised rib can be a single rib, and the second circuit board 320 is limited on one side of the single rib; it can also be two ribs, with a limiting groove arranged between the two ribs, and the second circuit board 320 is limited between the limiting grooves. In one embodiment, two adjacent positioning grooves share a rib, thereby saving space. The embodiment of the present invention does not limit the number of the positioning grooves 311. The number of the positioning grooves 311 is greater than or equal to the number of the second circuit boards 320. As shown in the example of FIG. 3, three positioning grooves 311 are provided on the cover plate 310. In other examples, other numbers of positioning grooves 311 can be set. When there are fewer second circuit boards 320, some of the positioning grooves 311 are left vacant.

[0056] In some embodiments, as Figure 1b shown, guide grooves 111 corresponding to the second circuit boards 320 are provided on the inner wall of the accommodation cavity 110. Each guide groove 111 includes a raised rib. Each second circuit board 320 inserted into the accommodation cavity 110 is inserted into the lower housing along its respective guide groove 111. Thereby, it is convenient for each second circuit board 320 to be inserted into place with its corresponding first insertion end 210, improving the insertion success rate and realizing rapid insertion.

[0057] In some embodiments, a signal processor 220 is provided on the first circuit board 200. The signal processor 220 transmits instructions to the second circuit board 320 through the first insertion end 210, so that the second circuit board 320 responds to the instructions to execute work tasks, and feeds back the execution results to the first circuit board 200 through the first insertion end 210. Thereby, signal transmission is realized based on the insertion structure of the first circuit board 200 and the second circuit board 320.

[0058] In some embodiments, an amplification and setting circuit is printed on the second circuit board 320. The second circuit board 320 receives the instructions transmitted by the first circuit board 200 through the first insertion end 210 through the second insertion end 321, and responds to the instructions to perform electrophysical quantity measurement by using the amplification circuit and transmits the measurement results to the first circuit board 200 through the second insertion end 321. Among them, the electrophysical quantity can be one or more of voltage, current, resistance value, power and other similar physical quantities.

[0059] In some embodiments, as Figure 1b shown, a partition 130 is provided in the lower housing 100. The first circuit board 200 is provided with a raised power connection end (not shown in the figure). The first circuit board 200 is placed on one side of the partition 130, and a battery cavity 140 for installing a battery is provided on the other side of the partition 130. The power connection end extends to the battery cavity, so that the power connection end is electrically connected to the battery. Figure 1bIn the illustrated example, the partition 130 is arranged on one face of the battery chamber, thus saving internal space.

[0060] In some embodiments, the first circuit board 200 sets up the electrical connection path between the power connection terminal and the first plug-in terminal 210. Based on the electrical connection path, the first circuit board 200 supplies power to one or more second circuit boards 320 through the first plug-in terminal 210. Thus, power supply and signal transmission are achieved simultaneously through the same plug-in interface, simplifying the connection structure and facilitating the realization of product functions.

[0061] In the hand-held calibration instrument of this embodiment, a circuit board with a plug-in interface is arranged on the lower housing and an accommodation chamber with an opening is set. Different combinations of circuit boards are set to realize different functions or functional combinations of the insertion components. The insertion components containing different combinations of circuit boards are inserted into the accommodation chamber of the lower housing. The plug-in terminals of the circuit boards on the insertion components are plugged into the plug-in terminals of the circuit boards in the accommodation chamber. Thus, different circuit boards can be selected according to requirements to construct the insertion components. After the constructed insertion components containing different circuit boards are plugged into the lower housing, hand-held calibration instruments with different functions are formed.

[0062] Embodiment 2

[0063] This embodiment provides a method for manufacturing a hand-held calibration instrument, as Figure 1a 、 Figure 1b 、 Figure 3a shown, the method includes:

[0064] Construct a lower housing 100 with an accommodation chamber 110, and an opening of the accommodation chamber 110 is arranged on the lower housing 100.

[0065] Arrange a first circuit board 200 in the lower housing 100, and at least two first plug-in terminals 210 are arranged on the first circuit board 200;

[0066] Construct an insertion component 300 that can be inserted into the accommodation chamber 110 in a matching manner. The insertion component 300 includes a cover plate 310 and at least one second circuit board 320. Different combinations of the at least one second circuit board 320 realize different functions or functional combinations. Each of the at least one second circuit board 320 in the at least one second circuit board 320 has a first end and a second end. The first end is the connection end with the first circuit board 200. A second plug-in terminal 321 that is matched and inserted with the first plug-in terminal 210 is arranged at the first end, and a wire connection port 322 for accessing the electrical signal to be measured or outputting the electrical signal is arranged at the second end. The cover plate 310 is provided with a hole corresponding to the wire connection port 322.

[0067] Insert the insertion component 300 into the accommodating cavity 110 from the opening of the accommodating cavity 110, so that the second plug-in end of each second circuit board 320 in at least one second circuit board 320 is plugged into one of at least two first plug-in ends 210 to establish an electrical connection with the first circuit board 200, and the cover plate 310 blocks the opening of the accommodating cavity 110 and is sealed together with the lower shell 100.

[0068] In some embodiments, one of the constructed second circuit boards 320 is an electrical signal measurement board 320a, which is combined with the first circuit board 200 to measure at least one signal of voltage, current, frequency, pulse, switch, loop current, and HART.

[0069] In some embodiments, one of the second circuit boards 320 is an electrical signal output board 320 b , and the electrical signal output board 320 b is combined with the first circuit board 200 to output at least one signal of voltage, current, frequency, and pulse output.

[0070] In some embodiments, one of the constructed second circuit boards 320 is an integrated board 320c for temperature measurement and analog output, and the integrated board 320c for temperature measurement and analog output is provided with a cold end compensation circuit. The integrated board 320c for temperature measurement and analog output is combined with the first circuit board 200 to realize the measurement and analog output of the thermal resistor RTD and the thermocouple TC.

[0071] In some embodiments, one of the second circuit boards 320 is a temperature measurement board 320 d , and the temperature measurement board 320 d is combined with the first circuit board 200 to implement the measurement of the thermal resistor RTD and / or the thermocouple TC.

[0072] In some embodiments, one of the second circuit boards 320 is a PT100 measurement template 320e. The PT100 measurement template 320e is combined with the first circuit board 200 to achieve the measurement of one or more PT100 thermal resistors.

[0073] In some embodiments, at least one second circuit board 320 includes three independent second circuit boards: an electrical signal measurement board 320a, an electrical signal output board 320b, and an integrated board 320c for temperature measurement and analog output. The electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output cooperate with each other to realize process verification of parameters; the electrical signal measurement board 320a is combined with the first circuit board to measure at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals; the electrical signal output board 320b is combined with the first circuit board 200 to output at least one of voltage, current, frequency, and pulse outputs; the integrated board 320c for temperature measurement and analog output is provided with a cold junction compensation circuit, and the integrated board 320c for temperature measurement and analog output is combined with the first circuit board 200 to realize the measurement and analog output of the resistance temperature detector (RTD) and the thermocouple (TC).

[0074] In some embodiments, at least one second circuit board 320 includes two independent second circuit boards 320: an electrical signal measurement board 320a and a multi-channel PT100 measurement template. The electrical signal measurement board and the multi-channel PT100 measurement template cooperate with each other to realize pressure and temperature recording; the electrical signal measurement board is combined with the first circuit board to measure at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals; the multi-channel PT100 measurement template is combined with the first circuit board to realize the measurement of multi-channel PT100 resistance temperature detectors.

[0075] The manufacturing method of the above handheld calibration instrument is only briefly described. For a detailed description, reference can be made to the embodiments of the handheld calibration instrument, and relevant content will not be elaborated here.

[0076] In the manufacturing method of the handheld calibration instrument of this embodiment, a circuit board with a socket is arranged in the lower housing and a receiving cavity with an opening is arranged. Insertion components that realize different functions or function combinations are set by combining different circuit boards. The insertion components containing different circuit board combinations are inserted into the receiving cavity of the lower housing, and the plug-in ends of the circuit boards on the insertion components are plugged into the plug-in ends of the circuit boards in the receiving cavity, so as to select different circuit boards according to requirements to construct the insertion components. After the constructed insertion components containing different circuit boards are plugged into the lower housing, handheld calibration instruments with different functions are formed.

[0077] Embodiment 3

[0078] This embodiment provides a handheld calibration instrument. The handheld calibration instrument is configured with a shape and weight suitable for being held by hand, and it is convenient for users to hold and operate in scenarios suitable for handheld operation. In combination with other embodiments, this embodiment takes the example of having three first plug-in terminals 210 provided on the first circuit board 200 and inserting a second circuit board 320. It should be understood that in other embodiments, three or more first plug-in terminals 210 may also be provided, and the number of first plug-in terminals 210 should be greater than or equal to the number of second circuit boards 320. As Figure 2a , Figure 2b , Figure 2c shown, in this embodiment, the three first plug-in terminals 210 provided on the first circuit board 200 are the plug-in terminal 210a, the plug-in terminal 210b, and the plug-in terminal 210c. A second circuit board 320 is inserted into the plug-in terminal 210a. It should be understood that in other embodiments, the second circuit board 320 may also be inserted into the plug-in terminal 210b or 210c.

[0079] In a specific example, when only one second circuit board 320 is inserted, the second circuit board 320 can be an electrical signal measurement board 320a. The electrical signal measurement board 320a and the first circuit board 200 are combined to measure at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART.

[0080] Among them, the electrical signal measurement board 320a may include an analog signal measurement unit and an information processing unit. The analog signal measurement unit obtains an analog electrical signal representing a certain detected quantity from the plug-in connection port 322 (for example, representing the detected quantity with a certain electrical signal quantity among parameters such as voltage, current, pulse, switch, etc.). The analog signal measurement unit measures the analog electrical signal quantity, and the analog signal measurement unit sends the measurement information to the information processing unit for processing to obtain a digital signal representing the electrical signal quantity, and sends it to the first circuit board 100 through the second plug-in terminal 321.

[0081] The specific implementation manner of the electrical signal measurement board 320a and the first circuit board 200 to achieve measurement is as follows:

[0082] Insert the electrical signal measurement board 320a into the plug-in terminal 210a. The first circuit board 200 supplies power to the electrical signal measurement board 320a through the plug-in terminal 210a. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends a measurement instruction to the electrical signal measurement board 320a through the plug-in terminal 210a and receives the measurement result returned by the electrical signal measurement board 320a after executing the measurement instruction.

[0083] It should be understood that when the electrical signal measurement board 320a performs a specific measurement task, the plug-in terminal 322a on the electrical signal measurement board 320a should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the electrical signal measurement board 320a can also be inserted into the plug-in terminal 210b.

[0084] Specifically, when performing a measurement task, the steps performed by the signal processor 220 are as follows:

[0085] The signal processor 220 sends a measurement instruction to the electrical signal measurement board 320a, instructing the electrical signal measurement board 320a to execute the measurement instruction, and the measurement instruction includes measurement items. The measurement items include at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals. Among them, the measurement instruction can be issued according to the user's operation. For example, the measurement instruction is issued according to the operation input by the user on the display interface.

[0086] After receiving the measurement instruction, the electrical signal measurement board 320a performs a measurement according to the measurement item, obtains a measurement result, and returns the measurement result to the first circuit board 200 through the plug-in terminal 210a. The first circuit board 200 receives the measurement result and processes it as needed, and can also display it after the processing is completed.

[0087] In a specific example, when only one second circuit board 320 is inserted, the second circuit board 320 can be an electrical signal output board 320b, and the electrical signal output board 320b is combined with the first circuit board to output at least one of voltage, current, frequency, and pulse signals.

[0088] The electrical signal output board 320b can include an analog signal generation unit and an information processing unit. Among them, the information processing unit receives an output instruction from the first circuit board 100 and determines the signal quantity to be output. The information processing unit sends the signal quantity to be output to the analog signal generation unit, and the analog signal generation unit generates an analog signal, and the analog signal corresponds to the signal quantity to be output. Considering that the generated analog signals may include various types such as voltage, current, pulse, and switch, correspondingly, the analog signal generation unit can also include a voltage signal generation unit, a current signal generation unit, etc. For example, when calibrating a certain pressure gauge, the signal type of the pressure gauge is 4-20 mA, and the range is 0-1.6 MPa. The first circuit board 100 obtains a calibration instruction, determines that the calibration point is 0 MPa, calculates that the corresponding electrical signal at the calibration point is 4 mA, and the first circuit board 100 sends an output instruction to the electrical signal output board 320b. The output instruction includes an output current signal of 4 mA. The information processing unit obtains the output instruction and after processing, sends an instruction of an output signal quantity of 4 mA to the analog signal generation unit. The analog signal generation unit outputs a signal quantity to generate a 4 mA electrical signal and outputs it through the wired connection port 322.

[0089] The specific implementation of the electrical signal output board 320b combined with the first circuit board 200 to achieve signal output is as follows:

[0090] Insert the electrical signal output board 320b into the insertion end 210a. The first circuit board 200 supplies power to the electrical signal output board 320b through the insertion end 210a. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends an output instruction to the electrical signal output board 320b through the insertion end 210a.

[0091] It should be understood that when the electrical signal output board 320b performs a specific output task, the insertion end 322b on the electrical signal output board 320b should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the electrical signal output board 320b can also be inserted into the insertion end 210b.

[0092] Specifically, when performing the output task, the steps executed by the signal processor 220 are as follows:

[0093] The signal processor 220 sends an output instruction to the electrical signal output board 320b, instructing the electrical signal measurement board 320a to execute the output instruction, and the measurement instruction includes output items. The output items include at least one of voltage, current, frequency, and pulse output signals. Among them, the output instruction can be issued according to the user's operation. After receiving the output instruction, the electrical signal output board 320b performs output according to the output item.

[0094] In a specific example, when only one second circuit board 320 is inserted, the second circuit board 320 can be an integrated board 320c for temperature measurement and analog output. The integrated board 320c for temperature measurement and analog output is provided with a cold junction compensation circuit. The integrated board 320c for temperature measurement and analog output and the first circuit board 200 are combined to achieve the measurement and analog output of a resistance temperature detector (RTD) and a thermocouple (TC).

[0095] Among them, the integrated board 320c for temperature measurement and analog output is similar to the electrical signal measurement board 320a, and collects electrical signal quantities representing temperature (such as the thermal electromotive force of a thermocouple). The difference from the electrical signal measurement board 320a is that the temperature measurement module further includes a temperature detection circuit, and a temperature sensor or other components capable of detecting the ambient temperature are arranged in the temperature detection circuit. The temperature detection circuit generates an electrical signal representing the ambient temperature, which is used to support the temperature compensation calculation of the thermocouple TC.

[0096] The specific implementation method of integrating the temperature measurement and analog output integrated board 320c with the first circuit board 200 to achieve measurement and analog output is as follows:

[0097] Insert the temperature measurement and analog output integrated board 320c into the plug-in end 210a. The first circuit board 200 supplies power to the temperature measurement and analog output integrated board 320c through the plug-in end 210a. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends a measurement instruction to the temperature measurement and analog output integrated board 320c through the plug-in end 210a and receives the measurement result returned by the temperature measurement and analog output integrated board 320c after executing the measurement instruction.

[0098] It should be understood that when the temperature measurement and analog output integrated board 320c executes specific measurement and analog output tasks, the plug-in end 322c on the temperature measurement and analog output integrated board 320c should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the temperature measurement and analog output integrated board 320c can also be inserted into the plug-in end 210b.

[0099] Specifically, when executing the measurement task, the steps executed by the signal processor 220 are as follows:

[0100] The signal processor 220 sends a measurement instruction to the temperature measurement and analog output integrated board 320c, instructing the temperature measurement and analog output integrated board 320c to execute the measurement instruction, and the measurement instruction includes measurement items. The measurement items include the measurement of resistance temperature detector (RTD) and thermocouple (TC). To complete the measurement task, the outputs of RTD and TC can be simulated during measurement. Among them, the measurement instruction can be issued according to the user's operation.

[0101] After receiving the measurement instruction, the temperature measurement and analog output integrated board 320c performs measurement according to the measurement item, obtains the measurement result and returns the measurement result to the first circuit board 200 through the plug-in end 210a. The first circuit board 200 receives the measurement result and processes it as needed, and can display it after the processing is completed.

[0102] In a specific example, when only one second circuit board 320 is inserted, the second circuit board 320 can be a temperature measurement board 320d. The temperature measurement board 320d and the first circuit board 200 are combined to implement one or more resistance temperature detector (RTD) measurements, one or more thermocouple (TC) measurements, or any one of one or more RTD and TC measurements. It should be understood that the RTD measurement and the TC measurement can be set to single-channel or can measure two or more channels simultaneously. If there is only a single-channel measurement task, this method can also be applied for single-channel measurement.

[0103] The specific implementation manner for the multi-channel temperature measurement board 320d and the first circuit board 200 to implement one or more measurements is as follows:

[0104] Insert the multi-channel temperature measurement board 320d into the insertion end 210a. The first circuit board 200 supplies power to the multi-channel temperature measurement board 320d through the insertion end 210a. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends a measurement instruction to the temperature measurement board 320d through the insertion end 210a and receives the measurement result returned by the temperature measurement board 320d after executing the measurement instruction.

[0105] It should be understood that when the temperature measurement board 320d performs a specific measurement task, the insertion end 322d on the temperature measurement board 320d should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the multi-channel temperature measurement board 320d can also be inserted into the insertion end 210b.

[0106] Specifically, when performing a measurement task, the steps executed by the signal processor 220 are as follows:

[0107] The signal processor 220 sends a measurement instruction to the temperature measurement board 320d, instructing the multi-channel temperature measurement board 320d to execute the measurement instruction. Among them, the measurement instruction can be issued according to the user's operation.

[0108] After receiving the measurement instruction, the temperature measurement board 320d performs a measurement to obtain a measurement result and returns the measurement result to the first circuit board 200 through the insertion end 210a. The first circuit board 200 receives the measurement result and processes it as needed, and can display it after the processing is completed.

[0109] In a specific example, when only one second circuit board 320 is inserted, the second circuit board 320 can be a PT100 measurement template 320e. The PT100 measurement template 320e and the first circuit board 200 are combined to implement the measurement of the PT100 resistance temperature detector.

[0110] The specific implementation of the PT100 measurement template 320e in combination with the first circuit board 200 to achieve measurement is as follows:

[0111] Insert the PT100 measurement template 320e into the insertion terminal 210a. The first circuit board 200 supplies power to the PT100 measurement template 320e through the insertion terminal 210a. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends a measurement instruction to the PT100 measurement template 320e through the insertion terminal 210a and receives the measurement result returned by the PT100 measurement template 320e after executing the measurement instruction.

[0112] It should be understood that when the PT100 measurement template 320e executes a specific measurement task, the insertion terminal 322e on the PT100 measurement template 320e should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that the PT100 measurement template 320e can also be inserted into the insertion terminal 210b in other examples. In this embodiment, the PT100 measurement template 320e can be set for one or multiple measurements, and preferably two-way measurements are set.

[0113] Specifically, when executing the measurement task, the steps executed by the signal processor 220 are as follows:

[0114] The signal processor 220 sends a measurement instruction to the PT100 measurement template 320e, instructing the PT100 measurement template 320e to execute the measurement instruction. Among them, the measurement instruction can be issued according to the user's operation.

[0115] After receiving the measurement instruction, the PT100 measurement template 320e executes the measurement to obtain the measurement result and returns the measurement result to the first circuit board 200 through the insertion terminal 210a. The first circuit board 200 receives the measurement result and processes it as needed, and can display it after the processing is completed.

[0116] In the embodiment of the present invention, different circuit boards are selected to form different insertion components, and then the different insertion components are inserted into the accommodation cavity 110 to form a handheld inspection instrument with different functions.

[0117] In the handheld calibration instrument of this embodiment, a circuit board with an insertion interface is provided on the lower housing and an accommodation cavity with an opening is provided. Insertion components of single circuit boards with different functions are provided. The insertion components containing the combined single circuit boards are inserted into the accommodation cavity of the lower housing. The insertion terminals of the circuit boards on the insertion components are plugged into the insertion terminals of the circuit boards in the accommodation cavity, so as to select different circuit boards according to requirements to construct the insertion components. The constructed insertion components containing different circuit boards are plugged into the lower housing to form a handheld inspection instrument with different functions.

[0118] Embodiment 4

[0119] This embodiment provides a handheld calibration instrument, which is set to have a shape and weight suitable for being held by hand, and is convenient for users to hold and operate in scenarios suitable for handheld operation. In combination with other embodiments, this embodiment takes the example of three first plug-in ends 210 being provided on the first circuit board 200 and inserting two second circuit boards 320. It should be understood that in other embodiments, more than two other first plug-in ends 210 can also be provided, and the number of first plug-in ends 210 should be greater than or equal to the number of second circuit boards 320. It should be understood that when inserting two second circuit boards 320, the two second circuit boards 320 can be used in cooperation with each other, or one of the two circuit boards 320 can be used. As shown in FIGS. 2a, Figure 2b , Figure 2c As shown, in this embodiment, the three first plug-in ends 210 provided on the first circuit board 200 are plug-in end 210a, plug-in end 210b, and plug-in end 210c, and a second circuit board 320 is inserted into each of the plug-in end 210a and the plug-in end 210b. It should be understood that in other embodiments, a second circuit board 320 can also be inserted into any two of the plug-in end 210a, the plug-in end 210b, and the plug-in end 210c.

[0120] In a specific example, when inserting two second circuit boards 320, it can be inserting an electrical signal measurement board 320a and a PT100 measurement template 320e, and the electrical signal measurement board 320a and the PT100 measurement template 320e are respectively inserted into the plug-in end 210a and the plug-in end 210b. The electrical signal measurement board 320a and the first circuit board 200 are combined to measure at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals. The PT100 measurement template 320e and the first circuit board 200 are combined to realize the measurement of one or more PT100 thermal resistors.

[0121] The specific implementation manner of the electrical signal measurement board 320a, the PT100 measurement template 320e and the first circuit board 200 to realize measurement is as follows:

[0122] The first circuit board 200 supplies power to the electrical signal measurement board 320a through the plug-in end 210a and supplies power to the PT100 measurement template 320e through the plug-in end 210b. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends measurement instructions to the electrical signal measurement board 320a through the plug-in end 210a, and the signal processor 220 sends measurement instructions to the PT100 measurement template 320e through the plug-in end 210b, and receives the measurement results returned after each measurement instruction of the electrical signal measurement board 320a and the PT100 measurement template 320e.

[0123] It should be understood that when the electrical signal measurement board 320a performs a specific measurement task, the plug-in terminal 322a on the electrical signal measurement board 320a should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the electrical signal measurement board 320a can also be inserted into the plug-in terminal 210b. When the PT100 measurement template 320e performs a specific measurement task, the plug-in terminal 322e on the PT100 measurement template 320e should be connected to an external device to be measured, and the device to be measured is omitted in the figure. It should be understood that in other examples, the PT100 measurement template 320e can also be inserted into the plug-in terminal 210b. The PT100 measurement template 320e can be set for one or multiple measurements, and preferably two-way measurement is set.

[0124] In this embodiment, two second circuit boards 320 working together are taken as an example for illustration. When one of the two second circuit boards 320 works, it can be implemented with reference to other embodiments of the present invention.

[0125] Specifically, when the signal processor 220 and the electrical signal measurement board 320a perform a measurement task together, the steps performed by the signal processor 220 are as follows:

[0126] The signal processor 220 sends a measurement instruction to the electrical signal measurement board 320a, instructing the electrical signal measurement board 320a to execute the measurement instruction, and the measurement instruction includes measurement items. The measurement items include at least one of signals such as voltage, current, frequency, pulse, switch, loop current, and HART. Among them, the measurement instruction can be issued according to the user's operation.

[0127] After receiving the measurement instruction, the electrical signal measurement board 320a performs a measurement according to the measurement item, obtains a measurement result, and returns the measurement result to the first circuit board 200 through the plug-in terminal 210a.

[0128] The first circuit board 200 receives the measurement result and processes it as needed, and can display it after the processing is completed.

[0129] Specifically, when the signal processor 220 and the PT100 measurement template 320e perform a measurement task together, the steps performed by the signal processor 220 are as follows:

[0130] The signal processor 220 sends a measurement instruction to the PT100 measurement template 320e, instructing the PT100 measurement template 320e to execute the measurement instruction. Among them, the measurement instruction can be issued according to the user's operation.

[0131] After receiving the measurement instruction, the PT100 measurement template 320e performs the measurement to obtain the measurement result and returns the measurement result to the first circuit board 200 through the plug-in terminal 210a. The first circuit board 200 receives the measurement result and processes it as needed, and can display it after the processing is completed.

[0132] It should be noted that in this embodiment, two second circuit boards, namely the inserted electrical signal measurement board 320a and the PT100 measurement template 320e, are taken as examples for illustration. In other embodiments of the present invention, two identical or different circuit boards can be selected from 320a, 320b, 320c, 320d, and 320e to form a combined function and be inserted into the accommodation cavity 110 to form a handheld inspection instrument with different functions.

[0133] In this embodiment, two circuit boards are selected to form different insertion components, and then the different insertion components are inserted into the accommodation cavity to form a handheld inspection instrument with different functions.

[0134] In the handheld calibration instrument of this embodiment, a circuit board with a plug-in interface is provided on the lower housing and an accommodation cavity with an opening is provided. An insertion component of two circuit boards is provided, and the insertion component including the combination of two circuit boards is inserted into the accommodation cavity of the lower housing. The plug-in terminals of the circuit boards on the insertion component are plugged into the plug-in terminals of the circuit board in the accommodation cavity, so as to realize the selection of different circuit boards according to requirements to construct the insertion component, and the constructed insertion component including different circuit boards forms a handheld inspection instrument with different functions after being plugged into the lower housing.

[0135] Embodiment 5

[0136] This embodiment provides a handheld calibration instrument. The handheld calibration instrument is set to have a shape and weight suitable for being held by hand, and it is convenient for users to hold and operate in a scenario suitable for handheld operation. Combining with other embodiments, in this embodiment, three first plug-in terminals 210 are provided on the first circuit board 200, and three second circuit boards 320 are inserted as an example for illustration. It should be understood that in other embodiments, more than two other first plug-in terminals 210 can also be provided, and the number of the first plug-in terminals 210 should be greater than or equal to the number of the second circuit boards 320. As Figure 2a 、 Figure 2b 、 Figure 2c shown, in this embodiment, three first plug-in terminals 210 provided on the first circuit board 200 are the plug-in terminal 210a, the plug-in terminal 210b, and the plug-in terminal 210c, and a second circuit board 320 is inserted into each of the plug-in terminal 210a, the plug-in terminal 210b, and the plug-in terminal 210c.

[0137] In a specific example, when inserting three second circuit boards 320, the inserted circuit boards can be an electrical signal measurement board 320a, an electrical signal output board 320b, and an integrated board 320c for temperature measurement and analog output. The electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output cooperate with each other to implement process verification of parameters.

[0138] It should be understood that when inserting three second circuit boards 320, the three second circuit boards 320 can be used simultaneously and cooperate with each other to work, or two of the circuit boards 320 can be used to cooperate with each other to work, or one of the circuit boards 320 can be used to work independently. In this embodiment, the case where the three second circuit boards 320 work together is taken as an example for illustration. The working of one or two of the three second circuit boards 320 can be implemented with reference to other embodiments of the present invention.

[0139] The electrical signal measurement board 320a is combined with the first circuit board 200 to measure at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART; the electrical signal output board 320b is combined with the first circuit board 200 to output at least one of the signals of voltage, current, frequency, and pulse output; the integrated board 320c for temperature measurement and analog output is provided with a cold junction compensation circuit, and the integrated board 320c for temperature measurement and analog output is combined with the first circuit board 200 to measure and analog output the resistance temperature detector (RTD) and thermocouple (TC).

[0140] In this embodiment, the specific implementation manner of the electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output in combination with the first circuit board 200 to achieve measurement is as follows:

[0141] The first circuit board 200 supplies power to the electrical signal measurement board 320a through the plug-in terminal 210a, supplies power to the PT100 measurement template 320e through the plug-in terminal 210b, and supplies power to the integrated board 320c for temperature measurement and analog output through the plug-in terminal 210c. A signal processor 220 is provided on the first circuit board 200. The signal processor 220 sends a measurement instruction to the electrical signal measurement board 320a through the plug-in terminal 210a, instructing the electrical signal measurement board 320a to execute the measurement instruction, and the measurement instruction includes measurement items. The measurement items include at least one of signals such as voltage, current, frequency, pulse, switch, loop current, and HART. The signal processor 220 sends an output instruction to the electrical signal output board 320b through the plug-in terminal 210b, instructing the electrical signal measurement board 320a to execute the output instruction, and the measurement instruction includes output items. The output items include at least one of signals such as voltage, current, frequency, and pulse output. The signal processor 220 sends a measurement instruction to the integrated board 320c for temperature measurement and analog output through the plug-in terminal 210c, and receives the measurement result returned after the integrated board 320c for temperature measurement and analog output executes the measurement instruction. Among them, the instruction output by the signal processor 220.

[0142] In this embodiment, three second circuit boards 320, namely the electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output, are selected as examples for illustration. It should be understood that according to different requirements, in other embodiments, other three can be selected for combination from the electrical signal measurement board 320a, the electrical signal output board 320b, the integrated board 320c for temperature measurement and analog output, the temperature measurement board 320d, and the PT100 measurement template 320e, and the corresponding function implementation methods can refer to this embodiment or be combined with other embodiments.

[0143] In this embodiment, three circuit boards are selected from the alternative second circuit boards 320 to form different insertion components 300, and the different insertion components 300 are inserted into the accommodation cavity 110 to construct a handheld inspection instrument with different functions.

[0144] For the handheld calibration instrument of this embodiment, a circuit board with a plug-in interface is provided on the lower housing and an accommodation cavity with an opening is provided. Three circuit boards are set to form an insertion component, and the insertion component including the combination of the three circuit boards is inserted into the accommodation cavity of the lower housing. The plug-in terminals of the circuit boards on the insertion component are plugged into the plug-in terminals of the circuit board in the accommodation cavity, so as to select different circuit boards according to requirements to construct the insertion component, and the constructed insertion component including different circuit boards is plugged into the lower housing to form a handheld inspection instrument with different functions.

[0145] Embodiment 6

[0146] This embodiment provides a handheld calibration instrument, such as Figure 1band Figure 4 As shown in Figure 4 , the handheld calibration instrument includes a lower housing 100, a screen 120, a battery chamber 140, and an insertion assembly 300. The insertion assembly 300 may be an insertion assembly 300 composed of one, two, or three second circuit boards 320 in other embodiments.

[0147] In this embodiment, the battery chamber 140 is internally provided with a rechargeable battery or a dry battery to supply power to the handheld calibration instrument. The display screen 120 may be a touch display screen, which is used to display the measurement results of the second circuit board 320, receive the input instructions of the user, and physical buttons may also be provided on the display screen 120.

[0148] The structure of this embodiment is as Figure 1a 、 Figure 4 shown in Figure 4 . The general lower housing 100 is provided with a screen 120 and a battery chamber 140. The lower housing 100 is provided with a receiving chamber 110 with an open end that can accommodate different insertion assemblies 300. The lower housing 100 is internally provided with a first circuit board 200 that is plugged and adapted to different second circuit boards 320, constructing a general lower housing for different handheld inspection instruments. The handheld calibration instrument constructed based on the above general lower housing 100 may specifically be a pressure calibrator, a process calibrator, a pressure indicator, a pressure temperature recorder, and a temperature and humidity recorder. Different combinations of second circuit boards 320 are required for different handheld calibration instruments. For example, a pressure calibrator usually requires an electrical signal measurement board 320a, a process calibrator usually requires an electrical signal measurement board 320a and an electrical signal output board 320b, and may also require an integrated board 320c for temperature measurement and analog output, a temperature measurement board 320d, and a PT100 measurement template 320e.

[0149] As Figure 1a 、 Figure 1b shown in Figure 1b , it is a general modular connection structure for a handheld calibration instrument. The specific structure description refers to other embodiments. Different combinations of multiple second circuit boards 320 construct different functional insertion assemblies 300. The receiving chamber 100 can be configured with different functional insertion assemblies 300, and different functional handheld calibration instruments are constructed by constructing different functional insertion assemblies 300.

[0150] A hole 311 corresponding to the wire connection port 322 is provided on the cover plate 310 of the insertion component 300. A guiding groove 111 is provided on the side wall of the lower housing 100 corresponding to the accommodation cavity 110. The whole guiding groove 111 or at least the part in contact with the second circuit board 320 has a certain elasticity, so that when the second circuit board 320 is inserted into the installation groove 111, the second circuit board 320 is clamped and not easily loosened. It should be understood that this anti-loosening design can also be achieved by other solutions. For example, a magnetic attraction structure adapted to the second circuit board 320 is provided in the guiding groove 111; for example, when the electrical function module is not frequently disassembled and assembled, an adhesive part is provided at the first end or side of the second circuit board 320 to be adhered to the guiding groove 111.

[0151] A plurality of first plug-in ends 210 are provided on the first circuit board 200 and electrically connected to the first circuit board 200. The plurality of first plug-in ends 210 are provided at one end of the lower housing 100 close to the accommodation cavity 110. Each of the plurality of first plug-in ends 210a, the first plug-in end 210b, and the first plug-in end 210c has a socket or a plug row structure. The positions of the plurality of first plug-in ends 210a, the first plug-in end 210b, and the first plug-in end 210c may be the same or different and are matched with the second plug-in ends 321 of the second circuit board 320. In this embodiment, when the number of the second circuit boards 320 is less than the number of the first plug-in ends 210, some of the first plug-in ends 210 are vacant. In an example, the accommodation cavity 110 can be configured with a plurality of different insertion components 300, and the second circuit board 210 on the insertion component 300 can be adapted to the guiding groove 111.

[0152] This embodiment provides a construction based on an insertion component 200 composed of different second circuit boards 320, applying a general lower housing 100 and a first circuit board 200. By inserting an insertion component 300 composed of different second circuit boards 320 into the accommodation cavity 110 of the lower housing 100, different handheld calibration instruments can be constructed. Circuit devices related to functions, such as a measurement circuit, a processing circuit, and related processing and storage components, are provided on the second circuit board 320 of the insertion component 300. In this embodiment, a general structure is set for the lower housing 100 of the handheld calibration instrument, so that it is adapted to the insertion component 300 combined with different second circuit boards 320, and the lower housing 100 can be plugged with different insertion components 300 to construct one of a pressure calibrator, a process calibrator, a pressure indicator, a pressure temperature recorder, and a temperature and humidity recorder.

[0153] In one example, the general lower housing 100 constructed above is applied, and the insertion component 300 containing the electrical signal measurement board 320a is inserted into the accommodation cavity 110 of the lower housing 100. The electrical signal measurement board 320a is placed in the accommodation cavity 110 and is plugged into the first circuit board 200 to be integrated and electrically connected to the first circuit board 200. An analog electrical signal representing a detected quantity (such as a pressure quantity) from the outside is obtained through the electrical signal measurement board 320a and converted into a digital electrical signal representing the detected quantity by the electrical signal measurement board 320a. The first circuit board 200 obtains the detected quantity and performs verification data recording to construct a handheld inspection instrument.

[0154] In the manner of the above example, in other examples, the insertion module 300 can be constructed by respectively applying the electrical signal output board 320b, the integrated board 320c for temperature measurement and analog output, the temperature measurement board 320d, and the PT100 measurement template 320e. And different handheld inspection instruments can be constructed based on the constructed insertion module 300 and the above general lower housing 100. When constructing a handheld inspection instrument by applying the electrical signal output board 320b, the electrical signal output board 320b generates an analog electrical signal representing the detected quantity according to the digital signal and outputs it to the device under measurement.

[0155] In one example, the general lower housing 100 constructed above is applied, and the insertion component 300 containing the electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output is inserted into the accommodation cavity 110 of the lower housing 100. The electrical signal measurement board 320a, the electrical signal output board 320b, and the integrated board 320c for temperature measurement and analog output are placed in the accommodation cavity 110 and are plugged into the first circuit board 200 to be integrated and electrically connected to the first circuit board 200. Each second circuit board 320 realizes its respective function to construct a handheld inspection instrument.

[0156] In the manner of the above example, in other examples, two or more circuit boards can be selected from the signal measurement board 320a, the electrical signal output board 320b, the integrated board 320c for temperature measurement and analog output, the temperature measurement board 320d, and the PT100 measurement template 320e as needed to construct the insertion component 300. For example, the signal measurement board 320a and the PT100 measurement template 320e are selected to construct the insertion component 300 to construct handheld inspection instruments with different functions.

[0157] In this example, an insertion component with different second circuit board configurations based on a common lower housing can be used to construct different handheld calibration instruments by importing corresponding control software into the first circuit board. For example, pressure calibrators, process calibrators, pressure indicators, pressure temperature recorders, and temperature humidity recorders. The main body hardware configuration is common throughout the process, that is, different product architectures can be designed through a single platform design and development, without the need for repetitive development according to different products. Furthermore, mass production of related components can be achieved without setting up production lines for different products separately, thereby improving product production efficiency.

[0158] In one example, the first circuit board 200 in the lower housing 100 can be of multiple models, making it easier to adapt to different combinations of the second circuit board 320, especially when the positions or models of the second plug-in ends of different second circuit boards 320 are not uniform. The first circuit boards 200 of multiple models can have the same or similar functions, while having first plug-in ends at different positions. The first circuit boards 100 of multiple models can have the same or substantially the same shape, so as to adapt to the same lower housing, increasing versatility, reducing manufacturing costs, and improving production efficiency. Since the first circuit board 200 can have the same or similar functions, handheld calibration instruments with different functions can be constructed based on different first circuit boards 200. For example, configuring a signal measurement board 320a to construct a handheld calibration instrument as a pressure calibrator; configuring processing and storage components to achieve digital display and storage of pressure calibration data to construct another handheld calibrator; configuring stronger processing and storage components to achieve digital display, graphical display, and large-scale storage of pressure calibration data to construct yet another handheld calibrator; and constructing another handheld calibrator by importing different control software. The handheld calibration instruments constructed in this example can be one of a pressure calibrator, a process calibrator, a pressure indicator, a pressure temperature recorder, and a temperature humidity recorder. Through modular design in this example, the replaceability of the insertion component 300 and the first circuit board 200 can be achieved, so that the shell design and manufacturing of different products can be realized through a single platform design and development, without the need for repetitive development and separate production according to different product lines, thereby improving product production efficiency.

[0159] In one example, the number of the second circuit boards 320 in the insertion component 300 can be one, two, three or more, and the maximum number of circuit boards in this embodiment can be five. The number of the second circuit boards 320 depends on the functional requirements of the handheld calibration instrument. For example, the developed general structure is applicable to pressure calibrators, process calibrators and temperature calibrators. The pressure calibrator needs to configure an electrical signal measurement board 320a in the accommodation cavity 110, and the process calibrator needs to configure an electrical signal measurement board 320a, an electrical signal output board 320b, and an integrated board 320c for temperature measurement and analog output in the accommodation cavity 110. The temperature calibrator needs to configure an integrated board 320c for temperature measurement and analog output in the accommodation cavity 110, and can also configure an electrical signal measurement board 320a according to needs.

[0160] In one example, the number of the first insertion ends 210 is set to three, namely a first insertion end 210a, a first insertion end 210b, and a first insertion end 210c. The three first insertion ends 210a, 210b, and 210c can be set at different positions with the same insertion direction. In one example, the first insertion end 210a is used to insert the electrical signal output board 320b, the first insertion end 210b is used to insert the electrical signal measurement board 320a, and the first insertion end 210c is used to insert the integrated board 320c for temperature measurement and analog output. Among them, the positions of the electrical signal measurement board 320a and the integrated board 320c for temperature measurement and analog output inserted on the first insertion ends 210b and 210c can be interchanged.

[0161] In one example, to make the configuration of the insertion component 300 more concise and convenient, the accommodation cavity 110 and the first plug-in end are configured such that the second circuit boards 320 on the insertion component 300 are parallel. For example, when configuring two second circuit boards 320 to be inserted into the first plug-in end 210a and the first plug-in end 210b, the first plug-in end 210a and the first plug-in end 210b are parallel to each other and have a spacing, thereby avoiding positional interference between them. For example, when there are two or three second circuit boards 320 on the insertion component 300, the three first plug-in ends 210a, 210b, and 210c are parallel to each other and spaced apart. In this example, the accommodation cavity 110 is a structure in the shape of an approximate cuboid surrounded by the lower housing 100. Specifically, taking the surface where the display screen 120 of the lower housing 100 is located as the front, the accommodation cavity 110 is surrounded by the front, left, back, and right sides of the lower housing 100. The front and back of the lower housing 100 are approximately parallel. The three first plug-in ends 210a, 210b, and 210c are parallel to the front of the lower housing 100 (if the front and back of the lower housing 100 are completely parallel, they are also parallel to the back of the lower housing 100). Then, the three first plug-in ends 210a, 210b, and 210c divide the accommodation cavity 110 into three mutually parallel spatial regions from front to back (not representing an order but only a direction, that is, it can also be from back to front here), thereby facilitating the mating and plugging of the second circuit boards 320 on different insertion components 300 with the corresponding first plug-in ends.

[0162] In the hand-held verification instrument of this embodiment, a circuit board with a plug-in interface is provided in the lower housing, an accommodation cavity with an opening is provided, different circuit boards are configured to form an insertion component, the insertion component including different circuit board combinations is inserted into the accommodation cavity of the lower housing, and the plug-in ends of the circuit boards on the insertion component are plugged into the plug-in ends of the circuit board in the accommodation cavity, so as to realize selecting different circuit boards according to requirements to construct the insertion component, and the constructed insertion component including different circuit boards forms a hand-held verification instrument with different functions after being plugged into the lower housing.

[0163] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and variations are obvious to those of ordinary skill in the art in this technical field. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technologies in the market, or to enable other ordinary technicians in this technical field to understand the disclosed embodiments.

[0164] As described above, only the specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art in the technical field disclosed by the present invention can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention.

Claims

1. A handheld calibration instrument, characterized in that, Comprising: A lower housing having a receiving cavity with an opening. A first circuit board disposed within the lower housing, with at least two first plug-in ends provided on the first circuit board. An insertion assembly that can be inserted into the receiving cavity in a matching manner. The insertion assembly includes a cover plate and at least one second circuit board. Different combinations of the at least one second circuit board achieve different functions or function combinations. Each second circuit board in the at least one second circuit board has a first end and a second end. The first end is provided with a second plug-in end that is matched and inserted with the first plug-in end, and the second end is provided with a wire connection port for accessing a to-be-tested electrical signal or outputting an electrical signal. The wire connection port is used to establish a connection between the handheld inspection instrument and the device under measurement. The cover plate is provided with a hole corresponding to the wire connection port. A signal processor is provided on the first circuit board. The signal processor transmits instructions to the second circuit board through the first plug-in end, causing the second circuit board to execute a work task in response to the instructions. After the insertion assembly is inserted into the receiving cavity from the opening, the second plug-in end of each second circuit board in the at least one second circuit board is inserted into one of the at least two first plug-in ends to establish an electrical connection with the first circuit board. The cover plate seals the opening and encloses with the lower housing to form a sealed whole. The handheld calibration instrument is set to have a shape and weight suitable for being held by hand.

2. The handheld calibration instrument according to claim 1, wherein The insertion assembly includes at least two second circuit boards, and each adjacent two of the at least two second circuit boards are spaced apart from each other. At least one of the at least two second circuit boards is parallel or coplanar with the first circuit board. Or, the at least two second circuit boards cross the first circuit board.

3. The handheld calibration instrument according to claim 1, wherein At least one of the at least two first plug-in ends is provided at one end of the first circuit board close to the receiving cavity and is coplanar with the first circuit board. Or At least one of the at least two first plug-in ends is provided at a connecting portion of the first circuit board. The connecting portion extends vertically from the side of the first circuit board and is electrically connected to the first circuit board. Or At least one of the at least two first plug-in ends is provided at one end of the first circuit board close to the receiving cavity and is coplanar with the first circuit board, and at least one of the at least two first plug-in ends is provided at a connecting portion of the first circuit board. The connecting portion extends vertically from the side of the first circuit board and is electrically connected to the first circuit board.

4. The handheld calibration instrument according to any one of claims 1 to 3, characterized in that, At least one of the at least one second circuit board includes: an electrical signal measurement board, which combines with the first circuit board to measure at least one of voltage, current, frequency, pulse, switch, loop current, and HART signals.

5. The handheld verification instrument according to any one of claims 1 to 3, characterized in that, At least one of the at least one second circuit board includes: an electrical signal output board, which combines with the first circuit board to output at least one of voltage, current, frequency, and pulse output signals.

6. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, At least one of the at least one second circuit board includes: an integrated board for temperature measurement and analog output, the integrated board for temperature measurement and analog output is provided with a cold junction compensation circuit, and the integrated board for temperature measurement and analog output and the first circuit board are combined to realize the measurement and analog output of the resistance temperature detector (RTD) and the thermocouple (TC).

7. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, At least one of the at least one second circuit board includes: a temperature measurement board, and the temperature measurement board and the first circuit board are combined to realize the measurement of the resistance temperature detector (RTD) and / or the thermocouple (TC).

8. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that At least one of the at least one second circuit board includes: a PT100 measurement template, and the PT100 measurement template and the first circuit board are combined to realize the measurement of the PT100 resistance temperature detector.

9. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, The at least one second circuit board includes: an electrical signal measurement board, an electrical signal output board, and an integrated board for temperature measurement and analog output. The electrical signal measurement board, the electrical signal output board, and the integrated board for temperature measurement and analog output cooperate with each other to realize process calibration. The electrical signal measurement board and the first circuit board are combined to realize the measurement of at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART. The electrical signal output board and the first circuit board are combined to realize the output of at least one of the signals of voltage, current, frequency, and pulse output. The integrated board for temperature measurement and analog output is provided with a cold junction compensation circuit, and the integrated board for temperature measurement and analog output and the first circuit board are combined to realize the measurement and analog output of the resistance temperature detector (RTD) and the thermocouple (TC).

10. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, The at least one second circuit board includes: an electrical signal measurement board and a PT100 measurement template. The electrical signal measurement board and the PT100 measurement template cooperate with each other to realize pressure and temperature recording. The electrical signal measurement board and the first circuit board are combined to realize the measurement of at least one of the signals of voltage, current, frequency, pulse, switch, loop current, and HART. The PT100 measurement template and the first circuit board are combined to realize the measurement of the PT100 resistance temperature detector.

11. The handheld calibration instrument according to any one of claims 1 to 3, characterized in that, The cover plate is provided with positioning grooves corresponding to the number of the second circuit boards. Each positioning groove includes a raised rib, and the second end of each second circuit board in the at least one second circuit board is limited in its corresponding positioning groove.

12. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, The inner wall of the accommodating cavity is provided with guiding grooves corresponding to the second circuit boards. Each guiding groove includes a raised rib, and each second circuit board in the at least one second circuit board is inserted into the lower housing along its respective guiding groove.

13. The handheld verification instrument according to any one of claims 1 to 3, characterized in that, An amplification and tuning circuit is printed on the second circuit board. The second circuit board receives the instruction transmitted by the first circuit board through the first plug-in end through the second plug-in end, and in response to the instruction, applies the amplification and tuning circuit to measure the electro-physical quantity, and transmits the measurement result to the first circuit board through the second plug-in end.

14. The hand-held calibration instrument according to any one of claims 1 to 3, characterized in that, A partition is provided in the lower housing. The first circuit board is provided with a raised power connection end. The first circuit board is placed on one side of the partition, and a battery cavity for installing a battery is provided on the other side of the partition. The power connection end extends to the battery cavity.

15. The handheld calibration instrument according to claim 14, characterized in that, The first circuit board is provided with an electrical connection path between the power connection terminal and the first plug-in terminal, and the first circuit board supplies power to the second circuit board through the first plug-in terminal based on the electrical connection path.

16. A manufacturing method of a handheld calibration instrument, characterized in that, Comprising: A lower housing configured with a receiving cavity having an opening; A first circuit board is disposed in the lower housing, and at least two first plug-in terminals are disposed on the first circuit board; An insertion assembly configured to be inserted into the receiving cavity in a matching manner, the insertion assembly includes a cover plate and at least one second circuit board, different combinations of the at least one second circuit board achieve different functions or function combinations, each second circuit board in the at least one second circuit board has a first end and a second end, the first end is provided with a second plug-in terminal that is matched and inserted with the first plug-in terminal, the second end is provided with a wire connection port for accessing a to-be-tested electrical signal or outputting an electrical signal, the wire connection port is used for the handheld inspection instrument to establish a connection with the device under measurement, and the cover plate is provided with a hole corresponding to the wire connection port; A signal processor is disposed on the first circuit board, and the signal processor transmits an instruction to the second circuit board through the first plug-in terminal, so that the second circuit board executes a work task in response to the instruction; The insertion assembly is inserted into the receiving cavity from the opening, so that the second plug-in terminal of each second circuit board in the at least one second circuit board is inserted into one of the at least two first plug-in terminals to establish an electrical connection with the first circuit board, and the cover plate seals the opening and is enclosed and sealed with the lower housing as a whole; The handheld calibration instrument is set to have a shape and weight suitable for being held by hand.

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