Claims:We claim,
1. Device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe which works on the basic principle of capacitance and has a micro-controller based advanced capacitance system for measuring the thickness of layers wherein the device mainly comprises of two units namely a probe and a signal conversion unit which are connected together form a complete system.
2. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 1 wherein among the various elements on which capacitance depends, namely overlapping area of two electrodes, distance between two electrodes, total length, percentage level of the material present and di-electric constant of the material filled in between the two electrodes, the device keeps the initial four elements constant and utilizes the fifth element namely the change in the di-electric constant of the material present in between the two electrodes as the basic measurement input for the probe to measure the thickness of the layer.
3. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 1 wherein the probe is submersible in water and ice, is fitted on the coils with the help of a mounting clamp arrangement and is connected to the signal conversion unit through a normal unshielded two wire cable.
4. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 3 wherein the probe has inbuilt features of high resolution, wide range, compensations, curve fitting and filters which eliminate the blur, noisy and non-linear patterns of change in the dielectric constant during the measurement of the thickness of the layer.
5. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 4 wherein the probe converts layer thickness capacitance into counts, modulates it over the carrier and sends it to the signal conversion unit which in turn processes the received frequency to convert it into useful data to determine the actual capacitance.
6. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 5 wherein the signal conversion unit is a micro-controller based multifunctional unit having four keys, two half digit displays and two status LEDs wherein the microcontroller initially measures the capacitance formed by the layer and then calculates the thickness by using the calibrated values recorded into its EEPROM memory following which these calculated values are further processed and refined to get error free values which are displayed in the form of percentage of layer thickness.
7. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 6 wherein the percentage value is mapped with the PWM signal to map over 4-20 milli ampere current signal output for further transmission to a programmable logic controller which acts as a controlling unit which is present at a location different from the location of the probe.
8. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 7 wherein the programmable logic controller has the logic for calculating the layer thickness by scaling and converting the values received from the signal conversion unit in the range of 0 - 50 mm of layer thickness which get displayed on the human machine interface station as the value of the layer thickness on the probe as well as the process value for the on-off control program written in the programmable logic controller.
9. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 8 wherein the process value of the layer thickness helps the operator in deciding the set point of the layer thickness such that whenever the layer thickness is greater than or lesser than the set point, the controller unit respectively closes or opens the solenoid valves so that the layer thickness is maintained as per the set point.
10. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe as claimed in claim 1 wherein the calibration and settings of the probe can be performed with the help of the signal conversion unit.
11. The device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe substantially herein described with reference to the foregoing description and drawings.
, Description:TITLE OF THE INVENTION:
Device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe

FIELD OF THE INVENTION:
The present invention relates to an electrode or a probe which is used for linear measurement of thickness of ice layered on coil of ice silo or ice bank tank, sludge accumulated at the bottom of a tank or scale developed on pipes using the principle of capacitance.

BACKGROUND OF THE INVENTION:
The dairy industry works by collecting milk from the suppliers and dispensing it to the consumers. Various dairies collect huge volumes of milk supplied to them by milkmen. This milk needs to be stored at lower temperature to protect it from souring. The quicker the milk is cooled after leaving the animal’s body, the better remains its quality. So the collected milk is stored in bulk milk cooling tanks. These are large storage tanks for cooling and holding of milk at a low temperature. Such tanks are one of the most important equipment of dairy farm. They are generally made out of stainless steel and used to store raw milk. Usually condensing units are provided in such tanks which cool the milk to a very low temperature.
With the development of the dairy industry, focus is shifted to providing quality milk at minimized cost. This has increased the requirement of milk processing due to which the refrigeration requirement has also increased. Moreover milk deteriorates very fast and so it should be processed and refrigerated as soon as possible after milking which is done twice a day. So a lot of energy would be required during these milking hours to refrigerate the milk and protect it from deterioration. To avoid this, ice bank tank system is used which chills and freezes water into ice during non-peak hours, which is melted during peak hours to provide increased quantity of chilled water for processing of the milk. Ice bank tanks are rectangular tanks having horizontal pipes used as coils over which ice is formed which is melted and consumed during peak load condition. Measurement of the quantity of ice on these coils is important.

US Patent 551288 describes an improved ice sensor which is particularly effective in measuring and quantifying non-uniform, heterogeneous ice typically found on aircraft leading edges and top wing surfaces. In one embodiment, the ice sensor comprises a plurality of surface mounted capacitive sensors, each having a different electrode spacing. These sensors measure ice thickness by measuring the changes in capacitance of the flush electrode elements due to the presence of ice or water. Electronic guarding techniques are employed to minimize baseline and parasitic capacitances so as to decrease the noise level and thus increase the signal to noise ratio. Importantly, the use of guard electrodes for selective capacitive sensors also enables distributed capacitive measurements to be made over large or complex areas, independent of temperature or location, due to the capability of manipulating the electric field lines associated with the capacitive sensors.
US Patent 5874672 discloses apparatus and method for determining the existence of ice or water on a surface from the capacitance between electrodes on said surface which is an improved ice sensor which is particularly effective in measuring and quantifying non-uniform, heterogeneous ice typically found on aircraft leading edges and top wing surfaces. In one embodiment, the ice sensor comprises a plurality of surface mounted capacitive sensors, each having a different electrode spacing. These sensors measure ice thickness by measuring the changes in capacitance of the flush electrode elements due to the presence of ice or water. Electronic guarding techniques are employed to minimize baseline and parasitic capacitances so as to decrease the noise level and thus increase the signal to noise ratio. Importantly, the use of guard electrodes for selective capacitive sensors also enables distributed capacitive measurements to be made over large or complex areas, independent of temperature or location, due to the capability of manipulating the electric field lines associated with the capacitive sensors.
US Patent Application 20020158768 gives inflight ice detector to distinguish supercooled large droplet (SLD) icing which is an ice detector having a pair of probes, each of which is used for determining the accretion of ice thereon. One of the probes in the assembly is configured so the smaller droplets of supercoooled water are inertially separated and flow away from the one probe. The ice accretion on the one probe is primarily from large (50 microns or greater) supercooled droplets. The ice accreting on the one probe is therefore biased to supercooled large droplets. The probes are connected to detection circuitry that will determine the ratio of the rates of icing between the probes so the presence of supercooled large droplets can be determined. In one form, a flow guide is arranged to create an airflow that carries smaller droplets past one of the probes without impinging on the probe, but the higher inertia, supercooled large droplets will impinge on that one probe.
US Patent Application 2002021125 provides a method for the nondestructive measurement of the thickness of thin layers having a probe, having a first coil device on an inner core, the geometrical center of which coil device and the geometrical center of at least one second coil device coincide, the at least one second coil device partially surrounding the first coil device, and an evaluation unit, to which signals of the coil devices are emitted during a measurement for ascertaining the layer thickness. A circuit is provided, by which the first and the at least one second coil devices are excited sequentially during a measurement.
EP 0929793 relates to a method to measure slag layer thickness on a molten bath. According to said method a probe fitted with an optical measuring head is moved through the slag layer and the position of the probe is determined so that the various optical characteristics of the molten bath, slag and air and/or the different temperature curves in the molten bath are measured as measurement quantities by the probe and thus the molten bath-slag and slag-air transitions are recorded. The invention relates to a device enabling said method to be used. Said device comprises a probe with a measuring head, which measures the intensity of an electromagnetic radiation in a given wavelength region of the optical spectrum.
DE 3401140 is an apparatus for continuously measuring the thickness of a material deposition produced by means of a coating unit on a carrier material, the sedimentation thickness is electrically determined on the measuring electrode (9) of a reference probe (50) by detecting an alternating current signal on the measuring electrode (9). The measuring electrode (9) is provided between two field generating electrodes (17, 23) arranged within a metal casing (1) provided with inlet openings (4, 5), which electrodes are subjected to the action of alternating voltages which are out of phase by 180 between each other and of which the amplitudes are set at the beginning of the measurement so that no signal can occur at the measurement electrode (9). The material deposition produced during the coating operation of a carrier material on the neighbouring measurement electrode (9) causes an out-of-tune of the field flow in the reference probe (50) and, consequently, a measuring current in the measurement electrode (9) connected to an evaluation circuit.
JP 03-338366 describes an ice amount detector of ice heat storage tank which accurately detects the amount of ice and ice distribution. For this a plurality of detection rods 6, 6... are disposed in an ice heat storage tank of an ice heat storage device for storing fine particle-shaped ice pieces and water so as to extend in a depth direction, and each detection rod 6 is fixed to a frame 5 located at a tank upper part. Further, probes 7, 7... are disposed at a predetermined interval longitudinally of the detection rods 6, and the frame 5 is vertically moved. Electric resistance is detected by rotational movement of the probes 7 to measure the amount of ice. Further, data from each probe is collected to estimate ice amount distribution in an entire heat storage water tank by an estimation part 14.
JP 08-186085 discusses an ice thickness measuring device for an ice storage apparatus for accurately and continuously measuring the thickness of an ice formed on a heat transfer tube surface more effectively than prior art. In the ice thickness measuring device for an ice storage apparatus wherein a heat transfer tube 1 is mounted in a heat storage tank and measuring electrode pair 3 and compensating electrode pair 5 are all connected in order to measure thickness of an ice formed on the tube 1 surface from a voltage drop at the pair 3, the pair 3 stood oppositely onto the tube 1 surface are provided via an insulating layer having thermal conductive properties similar to those of ice.
JP 2003-346805 discloses a thin film thickness measurement method and apparatus via a conductor layer, preventing measurement error due to bend or undulation in a substrate or a surface for stage movement, dispensing with large installations, and extensively comprehending a minute surface shape. Capacitance of the substrate 3, capacitance of an insulation film between the substrate 3 and the thin film 4, and capacitance ranging from the substrate 3 to the thin film 4 are found by applying an electric field between a probe 10 and a stage 8. The capacitance between the substrate 3 and the thin film 4 is measured at a plurality of positions over the entire surface of the thin film 4. The probe 10 is supported by a cantilever 11 so as to keep constant the contact load P of the probe 10 on the thin film 4. The contact area of the probe 10 with the thin film 4 is calculated by using a prescribed expression assuming that the load P is constant. Thickness distribution through all the area of the thin film 4 can be calculated from the measured capacitance and contact area.
RU 2373495 measures the ice layer thickness of the interior of the sludge line to process the reflected audio signal device of the complex is equipped with the detector of the backward signal of the result of physical influence on the sludge line. Recording computing mechanism is connected to the network adapter by the mode switcher with the possibility to provide two operational modes - training and information reservation mode and measurement of the ice layer thickness mode. Regulation of the analog-to-digital transducer, network adapter and the switcher is provided by the regulating mechanism connected to additional inputs of the mentioned blocks. This device allows to expand the features of the complex in the sphere of monitoring of the modes of sludge line interior ice formation during its operation in the minimum time frames, it also includes simplification of the scheme and reduction of the labour coefficient of measurements.
CA 1245721 is a frazil ice concentration measuring instrument is described in which constant currents are supplied to a reference probe and sensor probe and used to generate voltages across the electrodes in these probes. The sensing and reference voltages are amplified and compared in signal processing circuitry to generate an output voltage which is then integrated to give an average value of frazil ice concentration in a given time. A heating system using oil as the heat transfer medium is used to supply and maintain the electrodes of the sensing and reference probes just above freezing to prevent ice accumulation on the electrodes. The apparatus can also be used as general conductivity measuring instrument or for determining the concentration of a lesser conducting material in a more conducting liquid.
CN 102177446 relates to an ice thickness probe, ice thickness probe assembly and ice thickness monitoring apparatus which includes a longitudinally-extending probe rod, an insulator casing and a sleeve. The probe rod is fabricated from an electrically-conductive material. The insulator casing is fabricated from an electrically-insulative material and is wrapped around, is in contact with and extends along the probe rod. The sleeve is fabricated from a stiff yet resilient material and is wrapped around, is in contact with and extends along the insulator casing. The insulator casing and the sleeve are concentrically disposed about the probe rod as viewed in cross-section. An ice thickness probe assembly includes a frame structure, a reference bar and at least one ice thickness probe. An ice thickness monitoring apparatus is used in a thermal storage coil having a tank containing water and a tube disposed in the water so that, when the thermal ice storage coil is energized, ice is produced and accumulates on the tube.
CN 200410012164 gives an ice layer thickness sensor and its detecting method belonging to automatic detecting technology field, the positive electrode of the detecting power in the sensor forms a detecting loop together with the each metal detecting contactor arranged according to the scale, inner scale decoding switch circuit, conduction identification circuit and the negative electrode of the power through the measured media including water, ice, air between the inner and outer walls of the sensor, the inner microchip control circuit in the sensor generates decoding switch control signal according to a fixed coding order, the sensor is connected whose detection circuit correspondent to the metal measuring contactor to carry on the ice thickness measurement, the sensor can carry on fixed point continuous automatic detection to the ice thickness in river, reservoir, long distance transmission project, environment detection and so on.
CN 200510012794 relates to capacitor thickness sensor and its test method in the field of automatic testing technique, which is characterized by the following: forming testing circuit by the capacitor measurement circuit and single machine control circuit and the sensor inside scale code switch circuit through one set of metal capacitor test pole slice and metal capacitor testing pole slice space; generating scale code switch control signals along certain order by the senor inside single machine control to connect metal capacitor test pole slices adjacent two metal capacitor test pole slices to test the capacitor value and to determine the ice layer thickness sensor.
Indian Patent 251488 relates to a device for the capacitive determination and/or monitoring of a fill-level of a medium (1) in a container (2), comprising at least one probe unit (5), which is electrically insulated from the medium (1), and at least one electronics unit (7), which applies at least one electrical triggering signal (AS) to the probe unit (5), receives an electrical measuring signal from the probe unit (5), and evaluates the measuring signal with regard to the fill-level, the triggering signal (AS) being an electrical a.c. signal. According to the invention, the electronics unit (7) is configured so that it applies the triggering signal (AS) to the probe unit (5) in a measuring phase, applies a test signal (TS) to the probe unit (5) in a test phase, and in the test phase receives a test measuring signal from the probe unit (5), the test signal (TS) being such that it has at least one section with a substantially constant voltage.
This way, a variety of ice sensors are available in the prior art which have varied features. However, a sensor which can directly measure the thickness of ice formed on the coil or pipe along with a signal convertor/transmitter which can convert/transmit the signal given by the sensor in the desirable form is the need of the day.

OBJECT OF THE INVENTION:
The main object of the invention is to provide for a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe which gives linear, accurate and stable output with reference to the variation in the thickness of layers on pipe, tank or coil.
Another object of the invention is to provide for a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe with improved reliability such that the sensor and its accessories can withstand lower temperature range near zero degree and can remain in the same mounted position for years to measure the correct value of thickness of the layer.
Still another object of the invention is to provide for a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe which displays the layer thickness value on the control station of the control room using which values the operator/end user can visualize and predict the actual process going on in the tank like the melting or formatting of ice in ice silo.
Yet another object of the invention is to provide for a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe wherein based on the measurements obtained, the operator can analyze the load profile of the plant and schedule the operation of major machines like compressors, condensers, chillers and accumulators of refrigeration plants to optimize the energy and other resources which directly affect the cost per ton of refrigerant.

SUMMARY OF THE INVENTION:
The present invention is a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe using the basic principle of capacitance. This device contains two units, first is the sensing assembly which is an electrode/probe which is inserted vertically on pipe, coil or tank and the second is the signal conversion unit which transmits the signal received from the sensor in the desired form of current or voltage which helps in displaying and controlling the layer formation from the control station itself using the control system. The device especially used for measuring thickness of layer, is reliable in extreme conditions satisfying the industry needs of accurately measuring the layer thickness.

BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 displays the mounting arrangement of the probe of the sensor in horizontal and vertical tanks.
Fig. 2 displays the front view of the probe.
Fig. 3 displays the top view of the probe.
Fig. 4 displays the cable specifications of the device.

DETAILED DESCRIPTION:
The nature of the invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the detailed description.
Ice bank tanks used for storing the refrigerant in the refrigeration plants have disadvantages of requiring larger space and prove costly. So ice bank silos have been developed with the same configuration as milk storage tanks in dairies. These ice silos are cylindrical insulated vessels having circular coil bundles for accumulating ice inside the vessel. The construction material of ice silo and coil bundles is stainless steel. These coil bundles are divided into different sections as per requirement of the plant wherein each section can be controlled separately. The agitator or stirrer is mounted at the top side in the centre of the ice silo which is used to evenly distribute the water and ice throughout the vessel. The ice silo stores the refrigerant in the form of ice and the same refrigerant can be used in the peak load conditions which comes during the milking timings which is usually twice a day. This way ice silo is an important equipment which meets the load profile of the milk industry and manages the melting and formatting of ice. So it is important for the refrigeration industry to linearly control the ice formatting and melting process. For controlling this process a sensor is required which directly measures the thickness of the ice formed on the coil or pipe along with a signal convertor/transmitter which can transmit and convert the signal given by the sensor in the desirable form of current or voltage. The results obtained can be sent to the controller to take necessary action by generating output based on the feedback from the sensor.
The present invention is a device for measuring thickness of layered ice on pipe, sludge in tank or scale on pipe using the basic principle of capacitance. This device has a micro-controller based advanced capacitance system which has been specially developed for measuring the thickness of layer formed in tanks like the thickness of ice formed in an ice silo. It mainly consists of two units, a probe and a signal conversion unit. When connected together, these two units form a complete system to measure the thickness of the layer of sludge, ice or scale formed.
The device of the present invention has been specially designed to meet the stringent electrode geometry requirements so that it can be used for the above mentioned applications. This probe is submersible in water or ice and is fitted on the coils with the help of special mounting clamp arrangement as shown in Fig. 1. This probe is connected to the signal conversion unit via a normal unshielded two wire cable. The signal conversion unit of the present invention is a micro-controller based multifunctional unit having four keys, two half digit displays and two status LEDs. This unit evaluates the layer thickness which is the ice layer thickness in case of ice silos, and indicates and transmits it on 4-20 mA current loops to the ice silo control system. The calibration and settings of the probe can be performed with the help of this unit.
The basic principle employed for measuring the layer thickness using the device of the present invention is capacitance. The capacitance is a very basic elementary property of every material. When two conducting electrodes are separated by an insulator, a capacitor is formed. The capacitance of a capacitor is:
C= ( e0.A.Lt/D ) * ( 1- ( Lper /100)*(1+k) ) :-
This capacitance depends on five elements:
(a) Overlapping area (A) of two electrodes
(b) Distance (D) between two electrodes
(c) Total length (Lt)
(d) Percentage level (Lper) of the material present
(e) Di-electric constant (K) of the material filled in between the two electrodes.
The device of the present invention utilizes the 5th element (K) keeping all the remaining elements constant. After conducting a number of experiments and field trials, it has been established that there is a pattern of change in the dielectric constant of water during the starting point of freezing to the development of the desired maximum thickness of layer of ice in ice silos as well in other layers for measurement. This pattern of change in the dielectric constant, is the basic measurement input for probe to measure the thickness of the layer. Although this pattern is very blur, noisy and non-linear, the inbuilt features of the probe like high resolution, wide range, compensations, curve fitting and filters make this probe useful for the application.
The device of the present invention is suitable to measure the thickness of layers developed in tanks, pipes, tubes etc. Some of the application areas include:
(a) Ice thickness measurement in refrigeration industry
(b) Precipitation and sludge thickness measurement in refinery, pharmaceuticals and other process industries
(c) Measurement of scale development in pipelines and water treatment plants etc.
The general specifications of the whole system of the present invention are as follows:
User interface: 4 key inputs, 4 digits LED display output, 2 LEDs
Signal conversion unit operating temperature: 00 to 600 Celsius
Layer probe operating temperature: 50 to 500 Celsius
Maximum cable length from signal conversion unit to probe: upto 1 km
The electrical specifications of signal conversion module are as below:
Power supply voltage range: 18 to 30 VDC
Power supply consumption: approximately 15 mAmp, 0.3 Watt @ 24VDC
Analog Output: 4-20 mA with galvanic isolation (20-4 mA with reverse calibration)
Switching alarm: Short circuit protected 0-30 mA current output to drive
Display Output: 4 digit LED display and 2 bi-colour LEDs for status
Digital Output: wih RS485 with simple ASCII and MODBUS-RTU both
The mechanical (layer-probe) specifications for the sensor assembly are as follows:
Enclosure with IP65, submersible, nylon material
Mounting with specific clamp arrangement
Cable entry is for PG-9 Gland
Dimensions as per front view drawing (Fig. 2) and top view drawing (Fig. 3) are as follows:
Weight: 220gm (130 gm of “Layer-prob”+90 gm of “Capvel-Layer-eu”).
Cable specifications are as follows:
Unitronic LiYCY (TP) screened data transmission cable
Conductor standing is with fine copper wire strands
Temperature range: 050 C to +700 C
Measurement specifications are as follows:
Capacitance range: 10 pF to 50000pF
Capacitance resolution: +/- 0.1 pF
Capacitance Linearity: +/- 0.01 %
Accuracy: +/- 2% of full span
Response time: adjustable from 1 to 10 sec
To measure the thickness of the layer, the sensor present in the probe of the present invention converts layer thickness capacitance into counts, modulates it over the carrier and sends it to the evaluation unit. The evaluation unit processes this frequency to make it useful data to determine the actual capacitance. For this, the evaluation unit’s microcontroller initially measures the capacitance formed by the layer of ice and then calculates the thickness of ice by using the calibration values recorded into EEPROM memory of the evaluation unit. This calculated value of the thickness of ice is then processed further and refined to get error free readings. These error free readings are then displayed in the form of % ice thickness. This percentage value is mapped with the PWM signal to map over 4-20 milli ampere current signal output for further transmission.
The 4-20 milli ampere (mA) current signal is transmitted from the evaluation unit to a programmable logic controller (PLC) which acts as the controlling unit. This controlling unit can be present at a location different from the location of the probe. The PLC has the logic for calculating ice formation as well as ice melting. For example, when the evaluation unit gives an output of 4-20 mA, it gets transmitted to the controlling unit which does the scaling and converts the value in the range of 0 – 50 mm of ice thickness. This value of ice thickness gets displayed on the Human Machine Interface (HMI) station as the value of ice thickness on the probe as well as the process value for the on-off control program written in the PLC.
The process value of the ice thickness helps the operator determine the amount of ice formed on or melted from the pipe of coil. Depending on this value, the operator regulates the temperature by setting the set point on the HMI so that a desired limit of ice thickness is maintained on the pipe. For example, if the operator decides to maintain ice thickness of 25 mm on the pipe, he can set the set point of 25 mm. The controlling unit operates the solenoid valves of the coil, to maintain the ice thickness as per the set point. If the ice thickness is greater than the set point, the solenoid valves remain in closed condition so that due to the load, the ice melts. Similarly, if the ice thickness is less than the set point, the solenoid valves remain in open condition so that ice formation process takes place.
As mentioned above, the device of the present invention measures not only the thickness of ice layer, but can similarly be used to measure the thickness layer of sludge in tank or the thickness of scales developed on pipes or coils. Fig. 4 gives the cable specifications of the device of the present invention as use of specific cables is very important for the proper functioning of the probe.
The device of the present invention gives direct measurement of layer thickness of ice, sludge or scale by providing a 4 - 20 mA galvanic isolated signal output from signal conversion module to the control system thereby giving linear, accurate and stable measurement of layered thickness. The device has a wide capacitance range from 10pf to 50000pf and is low in power consumption with compact solutions. The device has advance features like adjustable turbulence, averaging, smart profiles, individual & pump control logics, RS485, MODBUS etc.
The device of the present invention is highly advantageous and useful in measuring the thickness of layered ice on pipe, sludge in tank or scale on pipe as the probes available earlier gave only digital output in the form of a single signal after the complete formation of the layer while the probe of the present invention continuously monitors the thickness of the layer and gives the output so that the operator can control the layer formation. Moreover the present invention works on the principle of capacitance in a frequency modulated carrier where the processing of the generated signal is done by AVR core. The digital filtering of the signals is done using the AVR core micro-controller. The software is implemented with artificial intelligence and fuzzy logic to make the readings immune to noise and interferences. The design and construction of the probe of the present invention has unique features not available in earlier probes. It has a very wide temperature range of -40 to +80 degree Celsius and is highly reliable as it gives silver-mica based measurement. Thus the probe of the present invention is highly advantageous.
Although the preferred embodiment as well as the construction and use have been specifically described, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the art without departing from the spirit of the invention. The invention has been described with reference to specific embodiments which are merely illustrative and not intended to limit the scope of the invention as defined in the claims.