Conductivity sensor

Abstract

To provide a conductivity sensor that can be cleaned by a fluid flow and can easily access externally mounted electrodes for inspection and cleaning.SOLUTION: A conductivity sensor is provided having an elongated non-conductive body. First and second electrodes extend from the body and are vertically separated from each other. Preferably, the body has a slot therein running partially away from the bottom of the body and being open in a radially outward direction. An upper portion of the slot defines a downwardly facing ledge. The first electrode extends through an upper portion of the body and terminates at a lower edge of the body. The second electrode, which is shorter than the first electrode, extends through an upper portion of the body and terminates at the ledge.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an apparatus for measuring the conductivity of a liquid, and more particularly to a conductivity sensor for sensing the conductivity of water. [Background technology]

[0002] This section provides background information related to the present disclosure that is not necessarily prior art.

[0003] Contact conductivity sensors are ideal for measuring the resistivity / conductivity of liquids ranging from pure and ultra-pure water to seawater, rinse waters and chemical solutions. Conductivity sensors generally rely on carefully sized and positioned electrodes to enhance the accuracy of the conductivity sensor. Some conductivity sensor embodiments utilize internally positioned electrodes to achieve the required sensor performance, which can contribute to electrode contamination that can severely affect electrode performance and therefore the accuracy of the conductivity sensor. Due to these concerns, it is important to easily clean the conductivity sensor, which typically requires the sensor to be removed from the sensing environment for cleaning due to the design of conventional conductivity sensors, active scrubbing and internal electrodes are difficult to access and can be easily damaged. Instead, conventional conductivity sensors require frequent manual maintenance to ensure the sensor is clean and readings accurately.

[0004] The electrodes may be disposed entirely within the housing, with holes disposed in the housing to allow fluid to enter the housing and contact the electrodes.

[0005] Therefore, there is a need in the art for a conductivity sensor that can be cleaned by fluid flow and has easily accessible externally mounted electrodes for inspection and cleaning.

[0006] Summary of the Invention This section provides a general overview of the disclosure and is not an exhaustive disclosure of its entire scope or any of its features.

[0007] In accordance with the teachings of the present invention, a conductivity sensor is provided having an elongated non-conductive body, with first and second electrodes extending from the body and vertically spaced apart from one another.

[0008] In a preferred embodiment of the invention, the conductivity sensor has an elongated, non-conductive cylindrical shape. The body has a slot extending partially upward from the bottom of the body and opening radially outward. The top of the slot defines a ledge or step or shelf. A first electrode extends through the top of the body and terminates at a lower edge of the body. A second electrode, shorter than the first electrode, extends through the top of the body and terminates at the ledge. For example, when the conductivity sensor is mounted vertically, the second electrode is vertically offset from the first electrode.

[0009] The electrodes are therefore directly exposed to the fluid. The distance between the two electrodes as well as the size of the button ends of the electrodes define the cell constant of the sensor.

[0010] This design has the advantage that the electrodes are much easier to clean because they are located outside the housing.

[0011] Further areas of applicability will become apparent from the description provided herein.The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0012] The drawings described herein are for purposes of illustrating selected embodiments only, not all possible implementations, and are not intended to limit the scope of the present disclosure. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view of a conductivity sensor made in accordance with the teachings of the present invention. [Diagram 2] FIG. 13 is another perspective view of the conductivity sensor from a different angle. [Diagram 3]FIG. 13 is another perspective view of the conductivity sensor as viewed from yet another angle. [Figure 4] FIG. 2 is a vertical cross-sectional view of the conductivity sensor. [Diagram 5] FIG. 2 is an exploded perspective view of the conductivity sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

[0015] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0016] The exemplary embodiments are provided so that the disclosure is thorough and fully conveys the scope of the present disclosure to those skilled in the art. Many specific details are described, such as examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that the exemplary embodiments can be embodied in many different forms, and that none of these should be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0017] The terms used herein are for the purpose of describing certain exemplary embodiments only and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring their execution in the particular order described or illustrated, unless specifically identified as an order of execution. It should also be understood that additional or alternative steps may be used.

[0018] When an element or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may not be intervening elements or layers. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0019] Terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or portions, but these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or portion from another region, layer, or portion. Terms such as "first," "second," and other numerical terms, when used herein, do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or portion described below can be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0020] Spatially relative terms such as "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as shown in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures is turned over, elements described as "below" or "below" the other element or feature would be oriented "above" the other element or feature. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein would be interpreted accordingly.

[0021] 1-3, a conductivity sensor 10 according to a preferred embodiment has an elongated non-conductive cylindrical body 12. Body 12 is preferably made from chlorinated polyvinyl chloride (CVPC) pipe. The body is essentially solid except for a notch or slot 14 that extends partially upwardly from a bottom 16 of body 12. Slot 14 opens radially outward.

[0022] The upper portion of the slot 14 defines a downward step or ledge 18 .

[0023] A first electrode 20 extends through the top of the body 12 and terminates at the lower edge or bottom 16 of the body 12 .

[0024] The second electrode 22 is shorter than the first electrode 20. The second electrode 22 extends through the top of the body 12 and terminates at the ledge 18.

[0025] The first electrode 20 and the second electrode 22 are made of an electrically conductive material, preferably stainless steel or an alloy of titanium grade 2. The first electrode 20 and the second electrode 22 are both press fit into the body 12.

[0026] A conductive button 24 is formed on the lower end of the first electrode 20 and extends from the bottom 16 of the body 12. Similarly, a conductive button 26 is formed on the lower end of the second electrode 22 and extends from the bottom of the ledge 18. Both buttons 24 and 26 have heads with diameters larger than the diameters of their respective electrodes to which they are connected.

[0027] A plastic or metal fitting or cap 28 has its lower portion connected to and sealed around the outer periphery of the upper portion of the body 12. The cap 28 includes a pair of male threads 30 and 32. The threads 30 provide a means for attaching the conductivity sensor 10 to a piping system at a test site. The threads 32 are typically attached to a pipe that allows an end user to route wires 38 from the electrodes 20, 22 to the sensor electronics 40 to take measurements (see FIG. 4). A rubber tubing 36 is used to support the wires 38 and helps provide wire strain relief.

[0028] In operation, the conductivity sensor 10 is placed in the liquid to be measured below the water level line WL. The conductivity sensor 10 is ideal for measuring the resistivity / conductivity of liquids ranging from pure and ultra-pure water to seawater, rinse water, and chemical solutions, and it is important that the conductivity sensor 10 is easy to clean. In contrast to conventional conductivity sensor designs that typically require the sensor to be removed from the sensing environment for cleaning, the electrodes 20, 22 of the conductivity sensor 10 are exposed and easily cleaned.

[0029] The foregoing description of the embodiments is provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, are interchangeable where applicable, and can be used in selected embodiments even if not specifically shown or described. It may also be modified in many ways. Such variations should not be considered as departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. an elongated non-conductive cylindrical body; first and second electrodes extending from the body, each electrode having an end spatially separated from an end of the other electrode; A conductivity sensor comprising:

2. the body having a slot therein extending partially upward from a bottom of the body and opening radially outward; an upper portion of the slot defines a downwardly extending ledge; the first electrode extends through a top of the body and terminates at a bottom edge of the body; the second electrode is shorter than the first electrode and extends through the top of the body and terminates at the ledge; The conductivity sensor according to claim 1 .

3. a first conductive button connected to the first electrode and extending from the bottom of the body; a second conductive button connected to the second electrode and extending from the bottom of the ledge; The conductivity sensor of claim 2 further comprising:

4. The conductivity sensor of claim 3 , wherein the button has a larger diameter than each of the electrodes.

5. The conductivity sensor of claim 4 , wherein the button is integrally formed with the electrode.

6. The conductivity sensor of claim 2 , wherein the first and second electrodes are stainless steel or a titanium alloy.

7. The conductivity sensor of claim 2 , wherein the body is a chlorinated polyvinyl chloride (CVPC) pipe.

8. a cap threaded onto the top of the body, the cap having male threads at the top configured to be connected to an external piping system at a test site; The conductivity sensor of claim 2 further comprising:

Images