Thermoelectric sensor for discrete measurement of partition level
(57) Abstract:The inventive device comprises a sealed enclosure connected to prochnostnymi covers, installed in the housing at its height, ensuring end-to-end walk through it environments. Thermocouples and heaters with elektroprovodnoi installed on the exterior walls of the covers. 3 C. p. F.-ly, 4 Il. The invention relates to measuring technique and can be used to indicate the presence or absence of fluid and discrete measurement of liquid level, including in the conditions of high temperatures, pressures and corrosive environment. Applications can be nuclear, chemical, food industry, and others that require measurement in confined and inaccessible to other observation volumes.Known thermoelectric sensors containing thermocouples, heating elements, corresponding elektroprovodnyi and electrical insulation, enclosed in covers, tightly-tightly closed at one end and connected the other end to the housing of the sensor, the latter is installed in the tank where the level measurement (see, for example, the United Kingdom patent N 2143950, CL G 01 F 23/24, published on the s are the complexity of the design, manufacturing, large inertia action, the difficulty of ensuring bryzgogasiteli, which affects the reliability of the testimony.Known thermoelectric sensor  contains sensitive elements in the covers of pipes placed in them by thermocouples and heaters, and each element has at one end an additional circular leaky case for protection against splashes, and all together the elements set out in the General case, communicated with the environment.The disadvantages are the complexity of design and manufacture, the sluggishness of action that is difficult to improve due to the need for accommodation in a cylindrical case of small diameter thermocouple, heater, insulation, and to ensure the reliability and the requested resource must be a sufficient wall thickness of the case, especially for corrosive or life-threatening environments. Because of the small size limited the choice of structural materials. Technological difficulties are exacerbated for a considerable length of sensor (tens of meters) and the stringent requirements to the inertia action. By the greatest number of matching signs thermoelectric sensor  is taken as a prototype.The purpose of accom is gnosti, reducing the inertia of the action.The objective is achieved by the fact that the covers are installed in the housing, ensuring end-to-end walk through it environments, and thermocouples and heaters installed on the exterior walls of the covers.Thermoelectric sensor includes a housing, which is made in the form of a pipe, and covers are made in the form of C-shaped tubes. The building is divided into several parallel structural parts, hermetically separated from the environment and from each other, and heaters thermocouples made with the ability to disable all but one, at each level of measurement. The body of the sensor is made of several parts connected firmly-firmly in height, and each part contains at least two covers, located at its opposite ends.In Fig. 1 there is shown a transmitter, a longitudinal section; Fig. 2 section a-a in Fig. 1; Fig. 3 cross-section B-B in Fig. 2; Fig. 4th place I in Fig. 3.Thermopile sensor consists of a tube 1, separately welded to a common flange and separately withdrawn from the housing 2 of the vessel containing the medium whose level is to be measured. Inside the pipes in several rows in height placed covers, made in the form With-shape curved t is titsa environment, the level which you want to measure, and inside hull pipes electroconductive environment, such as atmospheric air. On the outside walls of the C-shaped tubes 3 installed thermocouples 4 and through the electrical insulation 5 heater 6, made for example in the form of a spirally wound around the tube 3 wire. To reduce heat loss and reduce the temperature inside the enclosure is installed insulation 7. All the wires from all thermocouples and heaters are out. Each pipe 1 of the case is made from sections 8, near the upper and lower ends of which are embedded tubes 3, as this facilitates the installation of the pipes and the installation of thermocouples, heaters, insulation and placement of elektroprovodnyh.All this significantly reduces the complexity of manufacture of the proposed sensor is compared with the prototype facilitates the quality control and expands the range of structural materials that can be used for this transmitter. Much better splashproof, with no need for additional covers.The transmitter operates as follows. When passing current through the heater 6 of the wall of the tube 3 is heated. When lifting ur is 3, stops cooling, since the heat capacity of the gas is much less than the heat capacity of the liquid. The temperature change will cause a corresponding change of thermocouple signal.This design allows the use of different schemes of receipt of the signal, or the absolute change in temperature, or the temperature difference at the differential inclusion heated and unheated, pressurized thermocouples located at the same level in height in different buildings 1. Then when the number of pipes 1 three or more one or more tubes 3 at the same level in height are reserved, this increases the overall reliability of the sensor. Comparing the sensing element of the prototype, when thermocouple and the heater is placed inside the tube, you can see that it is more inertial than the offer, as the thickness of the material layers constituting the element of the prototype, is always greater than the wall thickness of the tube of the case, whereas in the proposed sensor is a thermocouple and heater are installed directly on the wall of the pipe that provides less lag and, accordingly, greater performance, which is important in measuring systems, ensuring safe operation. In addition, decreases potrebleniia in the manufacture, than staying inside a long, thin pipe. Therefore (due to availability) it is easier to select construction materials for manufacturing. Therefore, the proposed sensor exceeds the prototype of both performance and ease of fabrication, especially for large lengths of the transmitter, with large fluctuations in the level of the measured liquid height. 1. THERMOELECTRIC SENSOR FOR DISCRETE LEVEL MEASUREMENT SECTION of the MEDIA containing a sealed enclosure connected to prochnostnymi covers, mounted on the casing, thermocouples and heaters with elektroprovodnoi, characterized in that the covers are installed in the housing, ensuring end-to-end walk through it environments, and thermocouples and heaters installed on the exterior walls of the covers.2. The sensor under item 1, characterized in that the casing is made in the form of a pipe, and covers in the form of C-shaped tubes.3. The sensor under item 1, characterized in that the housing is divided into several parallel prochnostnyh parts, hermetically separated from the environment and from one another, and heaters thermocouples made with the ability to disable all but one, at each level of measurement.4. The sensor on p. 3, otlichalis the part contains at least two covers, located on its opposite ends.
FIELD: measuring engineering.
SUBSTANCE: device comprises fuel level indicator and rheostat pickup made of an analogue-digital converter with the balance input. The three-position switch is connected with the lever indicator. The device additionally has three resistive dividers, voltage stabilizer, and shunting resistor made of a 0.003-0.006-Om resistor. The rheostat level pickup is mounted inside the fuel tank vertically, and its linear horizontal size at this level is directly proportional to the area of the tank section in the horizontal plane at this level.
EFFECT: expanded functional capabilities.
FIELD: measuring engineering.
SUBSTANCE: method comprises pressing unit reinforced by electrodes with simultaneous forming of insulator between the electrodes. The space that is defined by surfaces of the electrodes is filled with casting plastic mass. The pressure tightness is provided by tightening the insulator with electrodes by means of a nut.
EFFECT: enhanced reliability.
FIELD: the invention refers to measuring technique and may be used for controlling bulk and liquid materials.
SUBSTANCE: the oscillating indicator of a level has a sensible element( a probe) 1 connected with an anchor 2, a driving arrangement 4 in the shape of a coil with a ferromagnetic core and also a sensor 5 of the displacements of the anchor, a drive-pulse generator 6 and an amplifier 7 and a relay block 9 successively connected. The amplifier is spanned with a regulated negative feedback fulfilled in the shape of a resistor 8. The sensor 5 of the displacements of the anchor may be fulfilled in the shape of a coil with a ferromagnetic core. At that the section of the anchor 2 between the coils is fulfilled out of non-magnetic material that prevents electromagnetic connection between the coils providing protection from high frequency oscillations in the system anchor-coil-amplifier.
EFFECT: allows to control the levels of the bulk and liquid materials being present in aggressive mediums, under pressure,( discharge)and at temperature till 200 degrees.
FIELD: instrument engineering.
SUBSTANCE: level meter sensor comprises hollow rigid base with the port in its bottom end, diaphragm, strain gage converter with box, flexible spacer arranged over periphery of the box, and tube whose one end is mounted pressure-tightly in the port of the support and the other end is connected to the space of the box. The diaphragm is made of a rigid material and mounted on the flexible spacer for permitting cooperation with the strain gage converter.
EFFECT: enhanced reliability and simplified structure.
FIELD: the invention refers to the field of instrument making and designed for control of the level of dielectric and current conducting liquids in hydraulic systems (fuel, freezing, accumulative etc) for example the level of oil or cooling agent in transport vehicles.
SUBSTANCE: the liquid level meter has a two-electrode capacitance sensor with an external 10 and interior 11 electrodes electrically connected with an electronic scheme having a stabilized source of power supply, an amplifier, a generator and a trigger. According to the first variant the capacitance sensor is fulfilled in the shape of a coaxial condenser "C". The interior electrode 11 of the sensor is fulfilled tubular and is mounted inside a fluoroplastic probing rod 12. The interior electrode 11 is connected to the input of a phase comparator which is additionally introduced in the scheme and whose output is connected with input of the trigger and the output of the last is provided with a line of delay and has two outputs - direct and inverse connected with a transistor key fulfilled with possibility of fulfillment of an operation "switched on" or "switched off". At that the electronic scheme is fulfilled on a digital integrated microchip. According to the second variant the interior electrode 11 of the coaxial condenser "C" is fulfilled tubular and is additionally provided with a protective shield 22. The shield 22 is fulfilled in the shape of a spiral spring out of bronze and electrically connected with the external electrode - the body 10 of the coaxial condenser "C".
EFFECT: increases sensitiveness and accuracy of measuring of the level of liquid.
6 cl, 4 dwg
FIELD: invention refers to control-measuring technique and is assigned for control and signaling about border of interface between mediums petroleum product-water in installations for purification water from petroleum products or watered petroleum products from water.
SUBSTANCE: sensor has flange, three electrodes with sleeves on their low ends filled with fresh water, moreover two of them are covered with dielectric insulation. Electrodes with sleeves are located inside tube of protective screen and are fastened in flange with aid of stuffing boxes-insulators. Screen in upper part has diaphragm ring with openings along circumference coinciding with openings in screen forming swinging compensator and is fastened to flange with aid of screws. Electrodes of sensor together with sleeves and electronic part form oscillating contour going in resonance at presence in space between electrodes of electric conductive medium (water) with following triggering of executive elements and at presence of water between electrodes of petroleum product resonance of contour stops.
EFFECT: increases reliability of work of sensor.
2 cl, 1 dwg
FIELD: physics, measurement.
SUBSTANCE: invention is related to the field of facilities for automation of different liquids level detection in industrial and household reservoirs, and also for detection of liquids availability and flow in pipelines. Method is based on application of two thermistors that have identical thermal characteristics, and includes heating of one of the thermistors by electric current and its cool-down due to heat transfer to environment, periodic measurement of voltage drop at thermistors, calculation of informative parameter, its comparison with threshold value and making decision on availability or unavailability of liquid at controlled level. At that one of thermistors is periodically heated by short pulses from power supply source. After heating is completed, ratio of non-heated and heated thermistors' voltages are repeatedly measured, and as informative parameter scaled time derivative is calculated by means of specified ratio measurement results array processing. Device for method implementation contains two thermoresistors, which are installed in sensitive element, connected to power supply source and which have temperature resistance coefficients (TRC) of the same sign and identical coefficient of heat emission in gas. Besides, it also contains analog-digital transducer and comparator, reference inlet of which is connected to source of reference signal, and outlet is connected with actuating device. Moreover, device is equipped with pulse switch and serially connected regulator of heating time and synchroniser, and also calculator of scaled derivative. For alarm on liquid flow availability, device is additionally equipped with the second comparator that is connected parallel to the first one, and the second actuating device.
EFFECT: higher efficiency of liquid level detection by increase of device actuation fast-action, reduction of power inputs and expansion of its application field.
13 cl, 3 dwg
FIELD: measuring technology.
SUBSTANCE: invention refers to a measuring device for determination of an amount d(V(z)) of conducting liquid of the conductivity LF by a capacity with vertically (z-direction) varied filling points. There is provided conductivity metre which among others has at least two electrodes extended in a z-direction. The capacitance parametres and/or the metres are ensured so that it/they can be described by means of at least one parametric function, fpi (V(z)) depending on V(z). At least one said parametric functions shall have exponential dependence on V(z). There is also described measuring element, and also method for determination of total amount of flowing liquid d (V).
EFFECT: simplified design of the device and method of measuring conductivity of the conducting liquid.
42 cl, 14 dwg
SUBSTANCE: method if based on measuring capacitance of a double-electrode capacitive liquid level sensor, which in turn in any sequence measures capacitance of the double-electrode capacitive liquid level sensor and capacitance of the same sensor is measured after connecting a capacitive sensor of dielectric properties to it, after which the level h from the upper end of the double-electrode capacitive liquid level sensor is calculated using the formula:
, where h is the level of the liquid in the reservior; CA is capacitance of the double-electrode capacitive liquid level sensor; CB is overall capacitance of the double-electrode capacitive liquid level sensor connected in parallel to the capacitive sensor of dielectric properties; A, B and D are structural parametres of the double-electrode capacitive liquid level sensor and capacitive sensor of dielectric properties. The device for measuring liquid level has a double-electrode capacitive liquid level sensor made in form of a coaxial capacitor, and two cylindrical electrodes. The lower end of the inner electrode of the double-electrode capacitive liquid level sensor is connected to one of the electrodes of the capacitive sensor of dielectric properties through the closing contact of a reed relay, and the lower end of the outer electrode of the double-electrode liquid level sensor is connected to the second electrode of the capacitive sensor of dielectric properties.
EFFECT: high accuracy of measuring the level of different liquids, as well as elimination of measurement errors caused by change in dielectric permittivity of the measured liquid.
2 cl, 1 dwg
SUBSTANCE: sensor for monitoring the level of a liquid has a housing and a printed-circuit board on which there is a substrate having one or two identical film resistors (thermistors) and contact pads (conductors). The printed-circuit board is in form of a plate, one short side of which is rigidly attached to the base of the housing and on the edge of the opposite free side there is a hole whose diameter is 2…4 times larger than the width of the substrate lying over the hole and made from thin heat-insulating material. Each film resistor (thermistor) is in 'point' form with dimensions in the range (0.15…0.5) mm • (0.5…0.5) mm and thickness not more than 0.0005 mm. The boundary surface between each film resistor (thermistor) and contact pads of the substrate (conductors) is in form of broken lines consisting of straight sections.
EFFECT: high mechanical strength of the structure.