Abstract: A pH-measuring method and device for monitoring and then correcting for electrode drift is provided. The device includes a pH-measuring electrode and more than one reference electrode. During operation, the pH-measuring device is place in contact with a sample. The pH value measured at each electrode pair is due to the electrical potential difference between the pH electrode and the reference electrode. The maximum and minimum pH values are determined, and then the remaining pH values are averaged together to generate an overall average pH. The maximum and minimum pH values are subtracted from the average pH to generate a difference which is then compared to a user-defined drift level to determine if a particular electrode is deficient. The pH values from deficient electrodes are not considered when the overall pH of the sample is determined.

Abstract: A small glass electrode and process for preparation thereof are disclosed. This small glass electrode is characterized in that said glass electrode, which has a bonded structure comprises a reference electrode composed of silver/silver chloride, a glass substrate having a pad embedded therein, said pad being composed of gold or platinum and circuit-connected to the reference electrode, and a silicon substrate having a (100) plane selectively etched by the anisotropic etching technique and comprising a groove for injecting an electrolyte composed of an aqueous solution containing chlorine such as KCl, or HCl, at least one hole for holding the electrolyte and a glass film formed in a portion corresponding to the reference electrode. By this structure, the small glass electrode can be easily manufactured at a low cost.

Abstract: In a method for calibration of a pH measuring element whose ion-permeable, hydrophilic polymer layer is brought into contact with an aqueous solution prior to calibration, the aqueous solution is displaced or replaced by a gaseous calibrating medium, and residues of the aqueous solution remaining in the ion-permeable polymer layer. The gaseous calibrating medium contains a known amount of at least one component which is acid or basic in aqueous solution which reacts with the remaining residues of the aqueous solution in the polymer layer, such that a defined pH value is established in the polymer layer, which is employed for calibration of the measuring element.

Abstract: In the pH glass electrode comprising a double-walled glass tube in which an electrical screen is provided between the walls, the inner glass tube is sealed at one end with a glass lid and at the other end with a pH-sensitive glass membrane which forms, with the glass tube, a cavity which is filled with internal reference solution and into which the reference electrode extends. A feed tube (10) and a drain tube (11) which are passed through the lid (5) and intended for the internal reference solution (8) are disposed in the internal glass tube (3), the drain tube (11) extending down to the lowest point in the cavity (7).

Abstract: In the pH glass electrode comprising a double-walled glass tube in which an electrical screen is provided between the walls, the inner glass tube is sealed at one end with a glass lid and at the other end with a pH-sensitive glass membrane which forms, with the glass tube, a cavity which is filled with internal reference solution and into which the reference electrode extends. A feed tube (10) and a drain tube (11) which are passed through the lid (5) and intended for the internal reference solution (8) are disposed in the internal glass tube (3), the drain tube (11) extending down to the lowest point in the cavity (7).

Abstract: A method and application for detecting and measuring the presence of a binding target material employs a semiconductor device having a receptor-covered surface topgate, separated by a dielectric layer from a substrate. Receptors attached to this surface exhibit a chemical selectivity function. Binding occurs in a test solution, with charge associated with the target material modulating at least one device characteristic. According to the present invention, measurement may occur under dry conditions, at a time and location different from when binding occurred, thus substantially eliminating problems associated with ionic shielding and reference electrodes, so prevalent with prior art wet measurement techniques. Preferably the device includes a backgate to which a bias may be applied to restore the device's pre-binding characteristics. Measurement of the restorative backgate bias provides a signal indicating binding of the desired target material.

Abstract: An ion-selective reference probe which is adapted for use with potentiomec measurement systems is disclosed. The reference probe is non-chloride based and employs a specially adapted electrolyte which is reversible (i.e. with regard to ionic activity). More particularly, the electrolyte includes appropriate concentrations of ethylenediamine and copper(II) ions in a solvent to permit reversibility of the electrolyte within a desired range. Junction potential between the electrolyte and a test solution is minimized by forming the electrolyte from a portion of the test solution.

Abstract: A small glass electrode and process for preparation thereof are disclosed. This small glass electrode is characterized in that said glass electrode, which has a bonded structure comprises a reference electrode composed of silver/silver chloride, a glass substrate having a pad embedded therein, said pad being composed of gold or platinum and circuit-connected to the reference electrode, and a silicon substrate having a (100) plane selectively etched by the anisotropic etching technique and comprising a groove for injecting an electrolyte composed of an aqueous solution containing chlorine such as KCl, or HCl, at least one hole for holding the electrolyte and a glass film formed in a portion corresponding to the reference electrode. By this structure, the small glass electrode can be easily manufactured at a low cost.

Abstract: A reference electrode including a body, a supply of flowable gel electrolyte, a wire electrode, and a tube for the electrolyte. The electrolyte is preferably contained in a cartridge within the body of the electrode and is capable of being dispensed into the tube in very small, metered, amounts, as needed.

Abstract: A novel series of chalcogenide glass compositions that are relatively highly selective for a specific ion in solution. When utilized as a sensing element for electrodes or similar analytical devices, a modified surface layer is formed on the surface of the glass in contact with the test solution. The surface layer being characterized by a surface ionic conductivity ranging from 10.sup.-7 to 10.sup.-2 S/cm, a diffusion coefficient ranging from 10.sup.-11 to 10.sup.-6 cm.sup.2 /s and having a ratio of electronic to ionic conductivity within the modified surface layer of not more than 1.0. Specific compositions having these unique morphology and transport properties are disclosed for the detection of cadmium, silver, thallium, mercury, copper and lead.

Abstract: An electrochemical sensor wherein the salt bridge is a unitary plug of semipermeable material which is saturated with an electrolyte. The plug has a spiral cut from its outer surface to the central bore of the plug. The spiral has at least one complete turn and starts at or near one end of the plug and stops at or near the other end of the plug. A layer of impermeable material is deposited in the plug to thereby form an ion impermeable spiral barrier.

Abstract: The glass electrode comprises a membrane of ion sensitive glass. The membrane comprises a composite material consisting of a matrix of ion sensitive glass and a dispersed filling material therein having higher tensile strength than the matrix. The membrane of the glass electrode is particularly resistant to mechanical stress and the glass electrode is i.a. applicable in a tc Pco.sub.2 electrode of the Severinghaus-type.

Abstract: An improved compact ion-concentration measuring apparatus having a removable sample testing module with gelatinized electrodes. The gelatinized portion of the electrodes can be formed with a jelly containing an acrylic polymer with sodium.

Abstract: A glass pH electrode which comprises a silver-silver bromide inner electrode and an electrode solution for the inner electrode which is a zwitterionic buffer solution.

Abstract: An improved ion-selective electrode assembly and method of preparing the same includes providing a substrate of an insulating material which has a laminated polyethylene terephthalate film layer over an electrically conductive layer. A series of adhering layers is applied over the film layer, with the layer farthest from the substrate being a deoximation silicone room temperature vulcanizing adhesive. Gelatinized internal liquid is positioned in an aperture over the electrically conductive layer, and an ion-responsive glass sheet seals the assembly.

Abstract: A pH sensor includes a unitary cylindrical semi-porous plug which is formed with a central bore and is also formed with a cavity near a first end of the plug. A pH electrode is positioned in the central bore and extends outwardly from the second end of the plug for contacting a specimen fluid, and a reference electrode is positioned in the cavity. The plug is saturated with an electrolyte to establish electrochemical conductivity between the reference electrode and specimen fluid. To prevent ions from the specimen fluid from migrating through the plug and contaminating the reference electrode, a plurality of notches are radially machined part way through the plug and filled with ion-impermeable epoxy. The notches are preferably oriented at oblique angles relative to the axis of the plug to form "dead end" ion traps that will immobilize and impede a substantial proportion of contaminating ions, thus prolonging the life of the electrode.

Abstract: Sodium ion selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed.The ion carriers of this invention are hemispherand compounds represented by the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently hydrogen, alkyl, alkenyl, cycloalkyl, aryl or a heterocyclic group and R represents Z-decyl, Z-octyl, 3-octyl, and cyclohexyl methyl.

Abstract: A method for analyzing water or other liquid, in particular rain water, comprises the steps of providing a collector comprising at least first and second volumetric cells and a mechanism for causing water to flow selectively into the cells and for causing water to flow selectively from the cells. Water is caused to flow into a first one of the cells while it is prevented from flowing into the other one of the cells. The water collected in the first cell is caused to flow to a property determining cell when the first cell has been filled to a predetermined volume, and simultaneously water is prevented from flowing into the first cell while it is now permitted to flow into the second volumetric cell. The water collected in the second cell is then permitted to flow to a property determining cell when the second cell has been filled to a predetermined volume, and simultaneously the water is prevented from flowing to the second cell while it is now permitted to flow to the first cell.

Abstract: A water analyzer having several electrodes of the type which normally interfere with one another. These electrodes include a first electrode which is an active measurement electrode which perturbs the solution in which it is used and a second electrode whose reading is affected by the operation of the first electrode. Accurate readings are provided by sequencing the operation of the electrodes so that they are not always operating at the same time. In addition, further correction of the readings is provided to compensate for the known error resulting from the operation of the active electrode or electrodes. Such electrodes read conditions such as pH, dissolved oxygen and conductivity.

Abstract: A safe failure ion selective combination electrode in which a signal unit provides a signal if combination electrode output falls outside a predetermined range.

Abstract: An electrode unit for use in an analyzer of blood and of liquids includes a cylindrical outer housing having open ends and a pair of top hat end plate bushings each having a central bore and a plug portion, the bushings being positioned in each end of the housing with the plug portion directed into the housing to form a filling chamber with the inner surface of the housing. A sodium glass capillary tube is mounted in the bores of the bushings. An annular groove is formed in an end flange portion of each bushing so that a connecting alignment ring may seat in the bushing annular grooves of two adjacent electrode units to center the electrode units.

Abstract: An ion selective electrode flow cell includes a first fluid conduit and at least two ion sensing electrodes each having ion sensing surfaces disposed within the first fluid conduit. A second fluid conduit and an ion sensing electrode having an ion sensing tip is disposed within the second conduit. There is an electrically conducting bridge connecting the first and second fluid conduits. A conductive member is disposed within the first fluid conduit proximate the ion sensing surfaces of two ion sensing electrodes and the bridge. A third fluid conduit may intersect the first fluid conduit and can include grounding for grounding fluid flowing through the third fluid conduit. Capacitors between exit and entry ports of the first and second fluid conduits and ground reduce electrical noise within the flow cell.

Abstract: A device capable of being mounted in a small opening in a reactor vessel, after having been inserted through a manway, which permits the continuous sampling of the contents of the reactor during a reaction, and continuous monitoring of the pH factor or other characteristic of interest. Electrical probe replacement is possible without disconnecting the device from the reactor vessel, and requires only a minimum of down time.

Abstract: A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Abstract: Electrochemical microsensors formed of a substrate containing means for sensing potential or current, including active and passive electronic devices and electronic circuits, and a micromachined structure containing at least one cavity overlying the sensing means, wherein the structure and substrate are bonded together at a temperature less than about 400.degree. C., in the absence of high voltage fields, using means not requiring highly planarized surfaces. A wide variety of materials can be utilized for both the substrate and overlying structure.Diverse embodiments are possible, having in common a cavity containing a chemically sensitive material and means for sensing potential or current.The resulting structural organization of materials transduces a chemical signal, such as concentration, to an electrical signal, which is then "processed" by the underlying FET or metallic connections.

Abstract: An improved electrode assembly of a modular configuration for sensing ion concentration includes a substrate mounted in a housing and being sandwiched by a first and second support layer of non-conductive material. A gelantinized solution is positioned in an opening between the first support layer and a substrate, while a second gelatinized solution is positioned in an opening between a second support layer and a substrate. Electric leads and electrodes are appropriately positioned on the substrate for operative contact with the respective gelatinized solutions. An ion-responsive member contacts one gelatinized solution, while an acqueous junction member extends through the respective support layers and substrates to contact another gelatinized solution.

Abstract: A flat shaped composite electrode includes a flat substrate having a high electrical insulating property. A flat inside pair of electrodes and a flat outside pair of electrodes are fixed on the substrate. A flat support layer having a high electrical insulating property overlays the electrodes and substrate. The support layer describes two holes into which a gelatinized internal solution is placed. An ion response glass membrane is mounted on the support layer and over one hole, while a liquid junction membrane is similarly mounted over the other hole.

Abstract: A pH measuring electrode assembly for immersion in a solution includes an enclosed cylindrical member having an aperture at a lower end thereof. An electrolyte is located in the cylindrical member above the level of the aperture and an electrode is disposed in this electrolyte. A ring formed of an ion porous material is mounted relative to the cylindrical member so that a portion of this ring is rotatable relative to and is covering the aperture in the cylindrical member. A suitable mechanism is also provided for indicating which one of a plurality of portions of the ring is covering the aperture and to keep track of which portions of the ring have already been used and become clogged. Preferably, the electrode assembly also includes a glass electrode member in the center thereof including a second electrolyte and electrode disposed therein.

Abstract: A reference electrode utilizes a small thin, flat membrane of a highly conductive glass placed on a small diameter insulator tube having a reference material inside in contact with an internal voltage lead. When the sensor is placed in a non-aqueous ionic electrolytic solution, the concentration difference across the glass membrane generates a low voltage signal in precise relationship to the concentration of the species to be measured with high spatial resolution.

Abstract: Disclosed is an enzyme sensor for determining a concentration of glutamate comprising an immobilize enzyme acting specifically to a substrate and a transducer for converting the quantitative change of a substance or heat which is produced or consumed during an enzyme reaction to an electrical signal, wherein the enzyme is glutamine synthetase and the transducer is the pH glass electrode or ion-sensitive field-effect transistor (ISFET). The enzyme sensor can be miniaturized and can accurately determine a concentration of glutamate even when it is low.

Abstract: An improved electrode assembly for measuring ions, such as a pH electrode, and method of forming the same is provided. A plastic support layer with an aperture is mounted over a base member having electrodes. A gelatinized internal solution is mounted in the aperture over the electrodes in a plasticized solution containing a hydrogen ion-responsive material is formed into a paste and is positioned over the gelatinized internal solution and the adjacent surrounding areas of the support layer. When the paste solidifies it forms a thin film plastic ion-selective response membrane that is integrally sealed to the support layer.

Abstract: A liquid junction electrode 10 formed from a silicon body 14 and having a glass membrane 22 attached thereto. A reference electrode is constructed by forming the glass membrane 22 from porous glass having a preferable pore size in the range of 40 angstroms to 75 angstroms. The porous glass membrane 22 has a coating 24 of glass containing mobile ions that is electrostatically bonded to the silicon body 14. Alternatively, a glass plug 92 is formed from a paste of ground glass and organic binder that is heated to cause formation of pores and bonding of the glass plug 92 to a silicon body 94. An ion-sensitive electrode is constructed by forming the membrane 52 from an ion-sensitive glass or by filling the pores of the porous glass membrane 22 with an ion-sensitive material.

Abstract: An electrochemical sensor for measuring an electrochemical parameter such as pH in a flowing liquid has a housing with a lateral cutout or indentation. An indicator electrode and a reference junction extend into the indentation from opposite sides so that they are facing one another and are axially aligned along a common longitudinal axis which is generally perpendicular to the flow of liquid.

Abstract: A testing method and apparatus for testing the condition of electrodes and their conductors in ion sensitive measuring or controlling systems, wherein the measuring circuit is disruptive and replaced by an impedance measuring circuit containing only one electrode, so that also failures of, for example, reference electrodes, soiling and deposits, and electrolyte loss, can be determined. The arrangement has sufficient accuracy to detect faults, defects and failures as they slowly come into existence.

Abstract: The precipitation or deposition of particles from a solution in a cell (61) which an electric field is applied between an anode (65,67,68) and a cathode (66), typically an electrolysis cell for the co-precipitation of mixed oxides but also cells for electrodeposition or the electrophoretic deposition of colloidal particles, is controlled by measuring the pH of the solution in the cell using a probe (72) shielded in a tube (73) from the migrating electric current and from gas bubbles. The pH of the solution is then adjusted to a selected value as a function of the measured pH, e.g. by varying the electrolysis current or by bubbling in acid vapor, air or base vapor.

Abstract: A sensor system for measuring the pH level in a process flow pipe, such system utilizing a sensing electrode that fits within, and is protected by, a rugged cylindrical metallic sheath. The sensing electrode is slid by an insertion tube through a ball valve into the process flow pipe. Two spaced collars with two pairs of restraint cables cooperate to retain the sensor system in alignment during the insertion procedure. After insertion, the sensor system is held in position by the pair of shorter restraint cables extending between the collars, while a compression nut is advanced onto a tube fitting to mechanically join the insertion shaft to the sensor system.

Abstract: An improved electrode for detecting ion concentration and a method of manufacturing such an electrode. The electrode includes concentric glass tubes, including an inner tube which is filled with a filling solution and a larger, outer tube which extends above the level of the filling solution in the inner tube. A metal contact is immersed in the filling solution and extends outside the inner tube through a hermetic seal to allow electrical contact to be made to the filling solution. The inner tube is made of a different glass from the outer tube so that the inner tube will absorb radiation at selected wavelengths which are transmitted by the outer tube. The inner tube is illuminated with radiation of the proper wavelength so that the inner tube melts and collapses around the metal contact to form the hermetic seal. In an alternate embodiment, the electrode has an inner tube which is made of two different types of glass. An apparatus for mechanizing the electrode sealing process is also described.

Abstract: A normal pH sensitive glass electrode is deactivated by exposure to thermal treatments at relatively high temperatures of approximately 190.degree. C. for predetermined periods of time until the nominal electrode sensitivity is reduced to very low levels such that the output potentials of such deactivated glass electrode approach the characteristics desired for a theoretically perfect reference electrode.Additionally, a method of forming a deactivated pH glass electrode including the steps of exposing a normal pH or other ion sensitive glass electrode to high temperatures in the order of 190.degree. C. or higher for predetermined periods of time is disclosed.

Abstract: The invention relates to halide-containing glass. Glass with anionic conductivity for fluorine comprises PbO, F, and a glass-forming agent. As the glass-forming agent boron oxide (B.sub.2 O.sub.3) is used, with the following proportions of the components, per cent by mass:PbO: 86.0 to 87.0F: 3.5 to 0.5B.sub.2 O.sub.3 : 10.5 to 12.5Glass with anionic conductivity for fluorine is intended, mainly, for making dividers of electric signals.

Abstract: An ion selective electrode device, in particular a pH-sensitive electrode device, employing an intercalation electrode (3) as contact material between an ion selective element (2) and an electrical connection (9).An intercalation electrode comprising an equilibrium mixture of two phases, at least one of the phases working as an intercalation electrode, is disclosed.The electrode device may be constructed as a solid state electrode device showing advantageous electrode properties.

Abstract: A combination pH/reference electrode is provided with the two electrochemical references being symetrically thermally insulated from the sensing membrane and being thermally adjacent each other. The portion of the pH fill buffer in contact with the inner surface of the sensing membrane is thermally insulated, as by KCl crystals, to rapidly equilibrate in temperatures with the sample solution.

Abstract: A flow through type glass electrode has a resin body having a hollow interior and having bores in the opposite ends thereof extending from the outside into the interior and aligned with each other, an internal electrode positioned in the interior, a straight unitary hollow glass capillary tube extending through the bores and interior and having a uniform diameter sample flow passage therethrough, sealing members in sealing engagement around the tube and in sealing engagement in the bores where the bores open into the interior, plugs closely fitted around the tube and closely fitted in the bores where the bores open out of the body and being spaced from the sealing members along the bores to define an insulating material receiving space therebetween and extending along each bore, an insulating material filling the insulating material receiving space, and an internal liquid filling the interior.

Abstract: Salt bridge liquid for use in potentiometric measurement of blood or a blood liquid.The salt bridge liquid contains Na.sup.+ -ions and HCOO.sup.- -ions in substantially equimolar amounts, preferably in a concentration larger than or equal to 1 M, in particular about 4 M.When this salt bridge liquid is used, the potentiometric measurement will give corresponding results when measuring a blood sample and the corresponding plasma sample because the suspension effect which is caused by the erythrocytes and which is seen when using other salt bridge liquids is substantially eliminated. Furthermore, different blood samples with the same ion concentration but with varying erythrocyte content will give corresponding measuring results.

Abstract: A flow system glass electrode in use for pH measurement, which houses the glass electrode body in a resin block to improve an impact resistance, the glass electrode body being sealed by a packing to be small-sized and improve the degree of freedom in the direction of the use, sample flow tubes each being equal in an inner diameter to a response film and separate from the glass electrode body in order to eliminate stagnation of a sample liquid, enable the measurement of a minute sample, and facilitate manufacture and assembly of the electrode, the sample flow tubes being connected with a liquid inlet and a liquid outlet at the glass electrode body through couplings respectively.

Abstract: A method of electrometrically monitoring the pH of an electrolyte in an electrolytic cell with a pH sensor having a reference electrode with a porous membrane is provided by placing the pH sensor in the electrolyte flow stream, floating the reference electrode at the cell potential, and monitoring the pH sensor readings via potential measuring apparatus.

Abstract: Process and apparatus for directly measuring the ion strength of an electrolyte solution is disclosed. The pH value of the electrolyte is measured by means of a first measurement with a first indicator dependent on the ion strength and by means of a second measurement with a second indicator dependent on ion strength in a manner different from the first indicator whereby the ion strength is computed by means of the approximation ##EQU1## J=ion strength Jo=ion strength upon calibrationpH'(N)=pH value, measured with a first indicator N dependent on the ion strength (HPTS)pH'(X)=pH value, measured with a second indicator X dependent on the ion strength, the ion strength dependence of which is different from that of the first indicatorW(N)=valency of the first indicatorW(X)=valency of the second indicatorwith ##EQU2## The ion strengths of other ions and of unknown electrolyte may also be computed.

Abstract: A chemically sensitive device for monitoring chemical properties is described. The device includes a depletion-mode field-effect transistor. Two electrical leads are connected between source and drain region of the field-effect transistor to monitor changes in current or potential resulting from changes in the amount of chemical to be monitored. A reference electrode is attached to a lower substrate surface of the field-effect transistor and electrically connected to the source via a highly doped region adjacent to the source and another highly doped region adjacent to the reference electrode, both having a polarity identical to the substrate. A sensing membrane which is specific to the chemical to be monitored is located on a portion of the substrate remote from the gate region but electrically connected to the gate region to alter conductance between the source and the drain in accordance with the presence or absence of the chemical to be monitored.

Abstract: The invention provides a chemical-responsive field-effect transducer operating in depletion-mode, or enhancement/depletion-mode, comprising: a semiconductor material having a pair of adjacent diffusion regions (1,2) of a certain doping polarity located at the surface and separated by a channel (3) of the same doping polarity, said channel being created by diffusion, ion-implantation, epitaxial growth, or creation of a surface inversion layer by controlled processing techniques or other means. The diffusion regions and channel region are supported by an insulating substrate (4) or semiconductor substrate of opposite polarity. Electrical insulator (6) and/or ion-barrier material (7) overlies the aforementioned channel region. An electroactive material (10) overlies said insulator and/or ion-barrier, such that the electroactive material will interact with substances to which it is exposed and control the charge-carrier density in the aforementioned channel.

Abstract: A pH electrode which is capable of withstanding repeated exposures to sterilizing temperatures. An electrode body having a pH sensing member is at least partially filled with a bed of electrochemically inert particles. After an internal reference is inserted into the particle bed, the bed is injected with a quantity of electrolyte which is sufficient to establish continuity between the sensing member and the internal reference, but which is not sufficient to produce destructive internal pressures when the electrode is subjected to sterilizing temperatures. The electrode is completed by forming a seal between the electrode body and the internal reference.

Abstract: An electrochemical electrode device comprising a tubular member having a bottom end adapted to be inserted into a liquid sample to be measured, and a top end which is closed by a cap member including electrical conductors by means of which the electrodes of the electrode device are connected to an outer cable. In order to facilitate the introduction of liquid or gel into an inner space defined within the tubular member as well as withdrawal of liquid or gel from that space, a longitudinally extending passage is formed within the cap member. This passage may be selectively opened and closed by means of a closure member which is received in a cavity extending transversely to and intersecting the longitudinal passage. The closure member is preferably in the form of a swingably mounted slide valve member or a rotatable cock member.