Meter electronics enclosure through which wireless signals can pass

Abstract

A housing 2 is provided that includes a body 201 further comprising a metal. A cover 200 is provided that is connectable to the body 201, and an antenna slot 202 is formed in the housing 2, and the antenna slot 202 is filled with a compound 210. A method of forming the housing is provided that includes forming the housing from metal and forming the antenna slot therein. The housing is etched and the compound is inserted into the antenna slot. Meter electronics are housed inside the housing, and wireless data signals are transmitted through the compound to communicate with the meter electronics.

Description

[Technical Field]

[0001] The embodiments described below relate to meters having interfaces, and more particularly to an enclosure for meter electronics that passes wireless signals. [Background technology]

[0002] Vibrometers, such as Coriolis mass flow meters, liquid densitometers, gas densitometers, liquid viscometers, gas / liquid specific gravity meters, gas / liquid relative density meters, and gas molecular weight meters, are commonly known and are used to measure fluid properties. Generally, a vibrometer comprises a sensor assembly and meter electronics. The material in the sensor assembly may be flowing or stationary. The vibrometer can be used to measure the mass flow rate, density, or other property of the material in the sensor assembly. The meter electronics typically performs calculations to determine the values ​​of the mass flow rate, density, and other property of the material in the sensor assembly.

[0003] The meter electronics are typically located within an interface, sometimes referred to as a transmitter, that is communicatively and / or mechanically coupled to the sensor assembly. More specifically, the meter electronics may be located within a housing, which is typically a rigid structure. FIG. 1 shows a prior art housing. The transmitter's exterior structure is metallic, typically aluminum. Due to the nature of the metal enclosure and its inherent shielding capabilities, wireless signals, such as UHF radio waves, including Bluetooth® signals, cannot pass through the housing. Therefore, wireless operation and / or control cannot be transmitted to or received from the electronics located within the housing.

[0004] Openings in housings for UHF transmission are not always possible based on the size and dimensions of the housing and its associated configuration. Additionally, products used in hazardous areas often require special spacing considerations that limit opening size adjustments.

[0005] Therefore, there is a need for a metal housing that allows wireless communications to pass through, yet maintains the structural integrity necessary for installation in hazardous and even explosive atmospheres. Summary of the Invention

[0006] According to one embodiment, a method of forming a housing is provided. The method includes forming the housing from metal and forming an antenna slot in the housing. The housing is etched and a compound is inserted into the antenna slot. The housing is assembled, and meter electronics are housed inside the housing. The meter electronics communicate with a wireless data signal transmitted through the compound.

[0007] According to one embodiment, the housing comprises a body further comprising a metal, and a cover coupleable to the body. An antenna slot is formed in the housing, and the antenna slot is filled with a compound.

[0008] [Aspect] According to one aspect, a method of forming a housing includes forming the housing from metal, forming an antenna slot in the housing, etching the housing, inserting a compound into the antenna slot, and assembling the housing, wherein the meter electronics are housed within the housing.

[0009] Preferably, the housing is connected to a flow meter.

[0010] Preferably, the compound comprises a fiber reinforced resin.

[0011] Preferably, the step of etching the housing includes etching a pore having a depth of 20 to 500 nm, and the step of inserting a compound into the antenna slot includes filling the pore with the compound.

[0012] Preferably, the step of etching the housing includes forming pores in the metal having a depth of 20 to 300 nm, and the step of inserting a compound into the antenna slot includes filling the pores with the compound.

[0013] Preferably, the step of forming the antenna slot in the housing includes forming a plurality of resin detents.

[0014] According to one aspect, the housing includes a body including a metal, a cover coupleable to the body, and an antenna slot formed in the housing, the antenna slot being filled with a compound.

[0015] Preferably, the compound is permeable to wireless data transmission.

[0016] Preferably, meter electronics is housed therein, said meter electronics being capable of sending and / or receiving wireless data transmissions through the compound.

[0017] Preferably, the compound comprises a fiber reinforced resin.

[0018] Preferably, the housing adjacent the antenna slot is etched.

[0019] Preferably, the etched housing includes pores having a depth of 20 to 500 nm.

[0020] Preferably, the etched housing includes pores having a depth of 20 to 300 nm.

[0021] Preferably, the antenna slot includes a plurality of plastic detents. [Brief explanation of the drawings]

[0022] Like reference numbers represent like elements in all drawings. It should be understood that the drawings are not necessarily to scale. [Figure 1] FIG. 1 shows a prior art vibrometer housing. [Figure 2] FIG. 2 shows a vibrometer 5 with an improved housing according to one embodiment. [Figure 3] FIG. 3 illustrates a vibrometer 5 sensor assembly according to one embodiment. [Figure 4] FIG. 4 shows the housing 2 according to one embodiment. [Figure 5A] FIG. 5A shows a cover 200 according to one embodiment. [Figure 5B] FIG. 5B shows another view of the cover 200 of FIG. 5A. [Figure 6A] FIG. 6A shows the cover 200 shown in FIGS. 5A and 5B with an antenna slot 202. FIG. [Figure 6B] FIG. 6B shows the cover 200 shown in FIG. 6A with material connection points 206 shown. [Figure 6C] FIG. 6C shows another view of the cover 200 of FIG. 6B. [Figure 7A] FIG. 7A shows a cover 200 having a filled antenna slot 202. [Figure 7B] FIG. 7B shows another view of the cover 200 of FIG. 7A. [Figure 8] FIG. 8 is a flow chart illustrating a method for forming a housing through which wireless data transmission can pass. DETAILED DESCRIPTION OF THE INVENTION

[0023] 1-8 and the following description depict specific examples to teach those skilled in the art how to make and use the best mode embodiments of a housing for meter electronics. Some conventional aspects have been simplified or omitted for the purpose of teaching inventive principles. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present disclosure. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations in the use of the housing. Consequently, the embodiments described below are not limited to the specific examples described below, but only by the claims and their equivalents.

[0024] FIG. 2 illustrates a vibrometer 5 having a housing 2 according to one embodiment. As shown in FIG. 2, the vibrometer 5 includes a sensor assembly 10 that is mechanically and communicatively coupled to the housing 2 via a feedthrough 15. The sensor assembly 10 can be inserted into a process line (not shown) at flanges 10a, 10b to receive and measure material and return it to the process line. The housing 2 can house the meter electronics.

[0025] 3 shows a vibrometer 5, with the housing 2 not shown for clarity. The vibrometer 5 includes a sensor assembly 10 and meter electronics 20, which are located within the housing 2 shown in FIG. 1. The sensor assembly 10 responds to the mass flow rate and density of a process material. The meter electronics 20 connects to the sensor assembly 10 via leads 100 and provides density, mass flow rate, and temperature information, as well as other information, via port 26.

[0026] The sensor assembly 10 includes a pair of manifolds 150 and 150′, flanges 103 and 103′ having flange necks 110 and 110′, a pair of parallel conduits 130 and 130′, a driver 180, a resistance temperature detector (RTD) 190, and a pair of pickoff sensors 170l and 170r. The conduits 130 and 130′ have two essentially straight inlet legs 131 and 131′ and outlet legs 134 and 134′ that converge toward each other at the conduit mounting blocks 120 and 120′. The conduits 130 and 130′ bend at two symmetrical locations along their lengths and are essentially parallel throughout their lengths. Brace bars 140 and 140′ serve to define axes W and W′ about which each conduit 130 and 130′ oscillates. Legs 131, 131' and 134, 134' of conduits 130, 130' are fixedly attached to conduit mounting blocks 120 and 120', which are in turn fixedly attached to manifolds 150 and 150'. This provides a continuous, closed material path through sensor assembly 10.

[0027] When flanges 103 and 103', having holes 102 and 102', are connected via inlet end 104 and outlet end 104' to a process line (not shown) carrying the process material being measured, the material enters the inlet end 104 of the meter through orifice 101 in flange 103 and is directed through manifold 150 to conduit mounting block 120, having surface 121. Within manifold 150, the material is split and directed through conduits 130 and 130'. Upon exiting conduits 130 and 130', the process material is recombined into a single stream within block 120', having surface 121' and manifold 150', before being directed to outlet end 104', which is connected to the process line by flange 103', having hole 102'.

[0028] The conduits 130, 130' are selected to have substantially the same mass distribution, moment of inertia, and Young's modulus about bending axes W-W and W'-W', respectively, and are appropriately mounted in the conduit mounting blocks 120, 120'. These bending axes pass through the brace bars 140, 140'. Because the Young's modulus of the conduit changes with temperature, and this change affects flow rate and density calculations, an RTD 190 is attached to the conduit 130' to continuously measure the temperature of the conduit 130'. The temperature of the conduit 130', and therefore the voltage appearing across the RTD 190 for a given current passing therethrough, is governed by the temperature of the material passing through the conduit 130'. The temperature-dependent voltage appearing across the RTD 190 is used by the meter electronics 20 in a well-known manner to compensate for changes in the elastic modulus of the conduits 130, 130' due to any changes in the conduit temperature. The RTD 190 is connected to the meter electronics 20 by leads that carry an RTD signal 195 .

[0029] Both conduits 130, 130' are driven in opposite directions about their respective bending axes W and W' in what is called the first out-of-phase bending mode of the flow meter by a driver 180. This driver 180 may comprise any one of a number of well-known configurations, such as a magnet attached to conduit 130' and an opposing coil attached to conduit 130 through which an alternating current is passed to vibrate both conduits 130, 130'. An appropriate drive signal 185 is applied to driver 180 by meter electronics 20 via leads.

[0030] Meter electronics 20 receives RTD signal 195 on lead 100 and sensor signal 165 appearing on lead 100, which carries left and right sensor signals 165l, 165r, respectively. Meter electronics 20 generates drive signal 185 appearing on lead 100 to driver 180, causing conduits 130, 130' to vibrate. Meter electronics 20 processes left and right sensor signals 165l, 165r and RTD signal 195 to calculate the mass flow rate and density of material passing through sensor assembly 10. This information, along with other information, is applied by meter electronics 20 as a signal via path 26. A more detailed discussion of vibrometer 5 and meter electronics 20 follows.

[0031] Mass flow measurement value

number

number

[0032] With respect to density, the resonant frequency at which each conduit 130, 130' will vibrate may be a function of the square root of the spring constant of the conduit 130, 130' divided by the total mass of the conduit 130, 130' containing the material. The total mass of the conduit 130, 130' containing the material may be the mass of the conduit 130, 130' plus the mass of the material within the conduit 130, 130'. The mass of the material within the conduit 130, 130' is directly proportional to the density of the material. Therefore, the density of the material may be proportional to the square of the period at which the conduit 130, 130' containing the material vibrates, multiplied by the spring constant of the conduit 130, 130'. Therefore, by determining the period at which the conduit 130, 130' vibrates and scaling the result appropriately, an accurate measure of the density of the material contained by the conduit 130, 130' can be obtained. Meter electronics 20 can determine the period or resonant frequency using sensor signal 165 and / or drive signal 185. Meter electronics 20 can include electronics and associated circuit boards housed and enclosed by housing 2, as described in more detail below.

[0033] 4 illustrates a housing 2 according to one embodiment. A vibrometer 5 is mechanically and communicatively coupled to the housing 2 via a feedthrough. The housing 2 may house the meter electronics. A cover 200 is coupled to a body 201 of the housing 2. An electrical conduit (not shown) may be coupled to the housing 2 via a joint 204.

[0034] 5A and 5B show a cover 200 for the housing 2. FIG. 5A shows the exterior surface, and FIG. 5B shows the interior surface. A metallic cover of this nature does not allow UHF radio waves to pass through. However, as shown in FIGS. 5A and 5B, this is merely a cover in manufacturing configuration to achieve the general shape of the cover 200. Manufacturing may be done by machining, casting, additive manufacturing techniques, combinations of these, and any other form of manufacturing method known in the art.

[0035] 6A shows the cover 200 depicted in FIGS. 5A and 5B after a subsequent subtractive manufacturing step to form the antenna slot 202 in the cover 200. Those skilled in the art will appreciate that if an additive manufacturing process is used to form the cover 200, the antenna slot 202 can be formed during the manufacturing of the cover 200. In one embodiment, any temporary support structure required for manufacturing can be utilized, which, upon removal, results in the structure shown in FIG. 5 or an equivalent configuration.

[0036] Because metal covers act as shields, attenuating or completely blocking UHF radio waves, it is advantageous to form antenna slots 202 in cover 200, thereby providing a signal path in and out of assembled housing 2. In the embodiment shown in Figures 6B and 6C, material connection points 206 are defined or created to ensure the necessary strength and structural integrity of cover 200. In the embodiment shown in Figures 6B and 6C, resin detents 208 are defined or created to provide additional space for resin to occupy, thereby providing additional strength and ensuring the structural integrity of cover 200.

[0037] 7A and 7B show the antenna slot 202 and resin detent 208 filled with compound 210 that allows UHF radio waves to pass through. This allows wireless data connections, such as Bluetooth®, to be established between the meter electronics enclosed within the housing 2 and an external electronic device. It is contemplated that other wireless data transmission spectrums and standards besides UHF and Bluetooth will also pass through compound 210. In one embodiment, compound 210 includes glass or carbon fiber blended with a resin such as polyphenylene sulfide (PPS), polyphthalamide (PPA), polybutylene terephthalate (PBT), or polyamide (PA) to match the linear expansion coefficient of the compound to the metal used for the housing 2. In some embodiments, the metal used for the housing is one of aluminum, aluminum alloy, stainless steel, magnesium, magnesium alloy, titanium, and titanium alloy. Such glass or carbon fiber reinforced compounds allow for strong adhesion between the metal and plastic.

[0038] 8 illustrates a method for forming a housing 2 through which wireless data transmission can pass. In step 800, the housing 2 is formed from a metal. As described above, the metal is one of aluminum, an aluminum alloy, stainless steel, magnesium, a magnesium alloy, titanium, and a titanium alloy. The housing may be formed by machining, casting, additive manufacturing, combinations thereof, or any other manufacturing method known in the art. The housing includes a cover 200 and a body 201.

[0039] In step 802, an antenna slot 202 is formed in the housing 2. The antenna slot 202 can be formed via a subtractive process, such as machining. The antenna slot 202 may also be formed via an additive process, such as 3D printing. Temporary supports may be formed during these steps. Material connection points 206 may be formed during these steps. Resin detents 208 may be defined or formed during these steps to provide additional space for the resin to occupy.

[0040] In step 804, the housing 2 is etched to form nano-sized pores in the metal. Typically, the housing 2 is first degreased and cleaned using standard methods known in the art.

[0041] The aluminum alloy may be first immersed in a basic aqueous solution (pH > 7) and then rinsed with water. Examples of bases used in the basic aqueous solution include alkali metal hydroxides such as sodium hydroxide (NaOH) and potassium hydroxide (KOH), soda ash (Na), anhydrous sodium carbonate, and ammonia. Alkaline earth metal hydroxides (Ca, Sr, Ba, Ra) can also be used. When using sodium hydroxide, an aqueous solution with a concentration of 0.1 to several percent is preferred. When using soda ash, an aqueous solution with a concentration of 0.1 to several percent is preferred. The housing is immersed for several minutes to treat the aluminum alloy surface. Immersion in the basic aqueous solution causes the aluminum alloy surface to dissolve as aluminate ions while releasing hydrogen, scraping the surface of the aluminum alloy and revealing a new surface. After this immersion process, the housing is rinsed with water.

[0042] Alternatively, acid etching may be performed in an aqueous acid solution with a concentration of a few percent to 40-50%, such as hydrochloric acid, nitric acid, sulfuric acid, or hydrofluoric acid, at room temperature or a slightly higher temperature, such as 20-50° C. The housing 2 is immersed for a few seconds to a few minutes.

[0043] Furthermore, a combination of alkaline etching and water rinsing followed by acid etching may be used. Water rinsing, alkaline etching, and / or acid etching steps may be performed successively.

[0044] When etching aluminum or aluminum alloys, the housing 2 can be further etched by using, for example, an aqueous solution of an amine compound in combination with a weakly basic solution, so that the amine compound molecules are adsorbed onto the surface of the aluminum alloy. Examples of such solutions include aqueous solutions of ammonia, hydrazine, or a water-soluble amine compound. As a result of this process, the surface of the aluminum alloy is very finely etched, with pores approximately 20 to 500 nm deep. In a preferred embodiment, the pores are 20 to 300 nm deep. Nitrogen compounds derived from the ammonia, hydrazine, or water-soluble amine compound remain on the surface.

[0045] The purpose of this step is to delicately attack the surface of the aluminum alloy, forming pores for adsorption of these nitrogen-containing compounds. Preferred water-soluble amine compounds include methylamine (CH3NH2), dimethylamine ((CH3)2NH), trimethylamine ((CH3)3N), ethylamine (C2H5NH2), diethylamine ((C2H5)2NH), triethylamine ((C2H5)3N), ethylenediamine (H2NCH2NH2), ethanolamine (monoethanolamine (HOCH)2CH2NH2), allylamine (CH2CHCH2NH2), diethanolamine ((HOCH2CH2)2NH), aniline (C6H7N), and triethanolamine ((HOCH2CH2)3N).

[0046] For example, a 3-10% aqueous solution of hydrazine monohydrate may be heated to 40-50°C, the housing 2 immersed in the solution for several minutes, and then rinsed with water. Similarly, a 15-25% ammonia solution may be used at a temperature of 15-25°C for 10-30 minutes, followed by rinsing with water. When other water-soluble amines are used, the temperature, concentration, and immersion time will vary depending on the aluminum alloy.

[0047] For titanium and its alloys, an aqueous solution of ammonium hydrogen difluoride with a concentration of a few percent and a temperature of 50-70°C can be used.

[0048] For magnesium and its alloys, either a chemical conversion process or electrolytic oxidation can be considered. A two-step immersion process can also be used, in which the housing is first immersed briefly in a weakly acidic aqueous solution for fine chemical etching. The fine etching step can use a weakly acidic aqueous solution with a pH of 2.0 to 6.0, such as organic carboxylic acids, such as acetic acid, propionic acid, citric acid, benzoic acid, phthalic acid, phenol, and phenol derivatives. An immersion time of 15 to 40 seconds is preferred, although longer times may be required depending on the process conditions.

[0049] A specific example of magnesium treatment will be described. The magnesium housing 2 is immersed in a 0.1-0.5% hydrated citric acid solution at approximately 40°C for 15 to 60 seconds and finely etched. This part is then rinsed with water. Next, an aqueous solution containing 1-5% potassium permanganate, 0.5-2% acetic acid, and 0.1-1.0% hydrated sodium acetate may be used as a chemical conversion treatment solution at 40-60°C. The magnesium alloy part is immersed for 0.5-2 minutes, rinsed with water, and dried in a hot air dryer at 60-90°C for 5-20 minutes.

[0050] In another example of magnesium treatment, the magnesium housing is finely etched by immersion in a 0.1 to 0.5% aqueous solution of hydrated citric acid at approximately 40°C for 15 to 60 seconds. This portion is then rinsed with water. Next, a 15 to 20% aqueous solution of anhydrous chromium (chromium trioxide) is prepared at 60 to 80°C as a chemical conversion treatment solution, and the housing 2 is immersed in this for 2 to 4 minutes and rinsed with water. This is then placed in a warm air dryer set at 60 to 90°C for 5 to 20 minutes to dry.

[0051] These are merely examples of various chemical etching processes for aluminum, magnesium, and titanium and their respective alloys. Other etching solutions and methods are contemplated and will be understood by those skilled in the art. The particular etching method is not critical to the present invention, so long as nanoscale pores are formed in the surface of the housing 2.

[0052] In step 806, compound 210 is inserted into the antenna slot. The housing is inserted into a mold in an injection molding machine and can be injection molded using a thermoplastic resin material. At high temperature and pressure, compound 210 is forced into the treated metal housing antenna slot 202 and resin detents 208, resulting in bonding between compound 210 and the nanoscale holes on the metal surface. As described above, compound 210 includes glass or carbon fiber blended with a resin such as polyphenylene sulfide (PPS), polyphthalamide (PPA), polybutylene terephthalate (PBT), or polyamide (PA) to match the compound's coefficient of linear expansion to the metal utilized in housing 2. The glass or carbon fiber may be up to 45% by weight.

[0053] The cured compound 210 may be machined to provide a finished surface. In one embodiment, the joint 204 may be machined from the housing 2 after the compound has cured.

[0054] In step 808, the housing is assembled with the electronics therein. The electronics are provided with means for transmitting, receiving, or both transmitting and receiving wireless signals. The particular electronics, receiver, or transmitter can be selected according to design preference and application. For example, a Bluetooth® device can be utilized within the housing if desired to connect to the electronics within the housing. Once the housing 2 is assembled and fully sealed, the wireless signal passes through a compound-filled antenna slot 802. While the antenna slot 802 is shown as being formed in the cover 200 of the housing 2, it is also contemplated that the antenna slot 802 could be formed in the body 201 of the housing 2.

[0055] The detailed description of the above embodiments is not an exhaustive description of all embodiments contemplated by the inventors as falling within the scope of the present description. Indeed, those skilled in the art will recognize that certain elements of the above-described embodiments can be combined or deleted in various ways to create further embodiments, and that such further embodiments will fall within the scope and teachings of the present description. It will also be apparent to those skilled in the art that the above-described embodiments can be combined in whole or in part to create additional embodiments within the scope and teachings of the present description.

[0056] Thus, while specific embodiments have been described herein for illustrative purposes, those skilled in the art will recognize that various equivalent modifications are possible within the scope of this description. The teachings provided herein may be applied to other housings for meter electronics, as well as the embodiments described above and illustrated in the accompanying drawings. The scope of the above-described embodiments should therefore be determined by the claims.

Claims

1. 1. A method of assembling a vibrometer housing assembly, comprising: forming the housing from metal; forming an antenna slot in the housing; defining a material connection point within the antenna slot; forming a plurality of resin detents within the antenna slot; etching the housing; inserting a compound into the antenna slot, the compound being capable of transmitting wireless data; housing meter electronics within said housing; A method comprising:

2. The method for assembling a vibrometer housing assembly of claim 1 , wherein the compound comprises a fiber-reinforced resin.

3. 2. The method for fabricating a vibrometer housing assembly of claim 1, wherein the step of etching the housing includes etching a pore having a depth of 20 to 500 nm, and the step of inserting a compound into the antenna slot includes filling the pore with the compound.

4. 2. The method for fabricating a vibrometer housing assembly of claim 1, wherein the step of etching the housing includes forming pores in the metal having a depth of 20 to 300 nm, and the step of inserting a compound into the antenna slot includes filling the pores with the compound.

5. A vibrometer housing (2), a body (201) comprising a metal; a cover (200) connectable to the body (201); an antenna slot (202) formed in the housing (2); a material connection point formed in the housing (2); a plurality of resin detents formed within the antenna slot; Equipped with The housing (2) has the antenna slot (202) filled with a compound (210).

6. The housing (2) according to claim 5, wherein the compound (210) is permeable to wireless data transmission.

7. 6. The housing (2) of claim 5, wherein meter electronics (20) is housed therein, said meter electronics (20) being capable of at least one of transmitting and receiving wireless data transmissions through said compound (210).

8. The housing (2) according to claim 5, wherein the compound comprises a fiber reinforced resin.

9. The housing (2) of claim 5, wherein the housing (2) adjacent the antenna slot (202) is etched.

10. 10. The housing (2) of claim 9, wherein the etched housing comprises pores having a depth of 20 to 500 nm.

11. 10. The housing (2) of claim 9, wherein the etched housing comprises pores having a depth of 20 to 300 nm.

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