Abstract: Disclosed herein is a method of finding an isotopic cluster in a polypeptide and determining the monoisotopic mass of the cluster. The method comprises an algorithm for finding an isotopic cluster based on a probabilistic model, defined by each of peaks in the isotopic cluster, and determining the monoisotopic mass of the isotopic cluster. The probabilistic model of the isotopic cluster includes characteristic functions for mass, that is, a function of the ratio of two peak intensities, and a function of the product of two ratios obtained from three peaks. These characteristic functions for mass define the shape of peaks acceptable in an actual isotopic cluster for the mass of any isotopic cluster. The algorithm of finding the isotopic cluster based on the functions uses the characteristics to score the degree of the approximation of any isotopic cluster to the spectral shape of a theoretical cluster.

Abstract: A method and apparatus generate a measured data set by: (i) providing a probe tip at a selected height from a doped region of a substrate, (ii) applying a probing signal to the probe tip, (iii) measuring a characteristic of an electrical interaction between the probe tip and the doped region of the substrate, and (iv) repeating steps (i) through (iii) for a plurality of different selected heights. A plurality of reference data sets are provided characterizing the electrical interaction between the probe tip and the doped region of the substrate as a function of height between the probe tip and the doped region of the substrate. Each data set corresponds to a different dopant density. The measured data set is compared to the plurality of reference data sets and based on the comparison, the dopant density of the doped region of the substrate is determined.

Abstract: The present invention relates to a system for determining particle transmittance Tx of a filter for use with a particle detection system to provide a filter warning for aspirated particle detection systems by detecting a level of first particles having a size indicative of smoke particles and which pass through the detection system; determining an integrated smoke hours value by integrating the detected level of first particles over time; estimating the smoke particle transmittance Tx of the filter by applying a predetermined weighting operation to the integrated smoke hours value. An empirical measure of a filter's particle transmittance Tx, due to at least first particles having a size indicative of smoke particles may be achieved by way of integrating a level of such first particles passing through a particle detection system over time to determine the proportion of smoke particles arrested by a filter, “integrated smoke hours”.

Abstract: A detection arrangement for detecting presence of an analyte in a sample includes a processor, a memory, a display, a color measuring device, and a temperature controller for maintaining a constant temperature or a temperature profile of the sample.

Abstract: The present invention relates to a process for the automated classification and analysis of data, said process comprising the steps of i) selecting an analytical method for use in an analytical experiment; ii) determining working parameters and conditions for the selected method, which parameters and conditions have an effect on the results obtained by using the selected method; iii) assigning to a set of data, said set of data including a) the type of the selected method and b) a specific combination of working parameters and conditions used in the analytical experiment a unique analytical method code (Hash value); iv) applying the method characterized by said Hash value to at least one reference sample and at least one or more further samples obtained from a process for preparing said sample, in which process at least one parameter such as temperature, solvent, or ratio of reactants etc.

Abstract: Methods and devices to detect analyte in body fluid are provided. Embodiments include processing sampled data from analyte sensor, determining a single, fixed, normal sensitivity value associated with the analyte sensor, estimating a windowed offset value associated with the analyte sensor for each available sampled data cluster, computing a time varying offset based on the estimated windowed offset value, and applying the time varying offset and the determined normal sensitivity value to the processed sampled data to estimate an analyte level for the sensor.

Abstract: A method of calibrating glucose monitor data includes collecting the glucose monitor data over a period of time at predetermined intervals, obtaining reference glucose values from a reference source that temporally correspond with the glucose monitor data obtained at the predetermined intervals, calculating the calibration characteristics using the reference glucose values and corresponding glucose monitor data to regress the obtained glucose monitor data, and calibrating the obtained glucose monitor data using the calibration characteristics. In additional embodiments, calculation of the calibration characteristics includes linear regression and, in particular embodiments, least squares linear regression. Alternatively, calculation of the calibration characteristics includes non-linear regression. Data integrity may be verified and the data may be filtered.

Abstract: In one embodiment, we describe a method that generates seasonality rules for anomaly detection for a hierarchical/tree based data structure. A new algorithm for processing nodes in hierarchy, as well as business rules for nodes, is described. Variations and examples are given to describe different scopes and embodiments of the invention. Exclusion criteria and children nodes are used as some examples for the implementations, with flow charts to describe the methods of application, as examples.

Abstract: Reference features are updated based on a previous scan during each mass spectrometry scan of a sample. Reference features with reference feature confidence values are generated from a plurality of initial scans. For each subsequent scan of a sample, sample features and sample feature confidence values are calculated. The reference features and sample features are aligned to determine common features. Constants are determined for an equation of mass of the mass spectrometer using confidence weighted regression of the common features. The constants and the equation of mass are used to calculate new mass values for the sample features. The reference features are updated using the sample features and the reference feature confidence values are recalculated in order to maintain the accuracy of reference features for calibration.

Abstract: Apparatus is provided for measurement and display of at least one characteristic of molten metal contained in a metal processing vessel that includes a probe supported by an immersion end of a lance. The probe is adapted to be submerged in the molten metal to obtain data in analog form identifying at least one characteristic of the metal while a module is connected to an end of the lance opposite from the immersion end. The module contains electronic circuitry for receiving analog data and for converting the analog data into digital form, and the module also contains electronic circuitry for transmitting digital data to a remotely located receiving device which may be a microprocessor used in readout and control of the metallurgical process.

Abstract: This method for estimating biological or chemical parameters in a sample (E) comprises steps consisting of putting (102) the sample (E) through a processing chain, obtaining a signal representative of said biological or chemical parameters as a function of at least one variable of the processing chain, and estimating (104, 106, 108, 110) said biological or chemical parameters using a signal processing device by Bayesian inference, on the basis of a direct analytical modeling of said signal as a function of said biological or chemical parameters of the biological sample and as a function of technical parameters of the processing chain. At least two of said biological or chemical and technical parameters have a probabilistic dependence relationship between each other and signal processing by Bayesian inference is further accomplished on the basis of modeling by a conditional prior probability distribution of this dependence.

Abstract: A method of mapping concentrations of airborne matter from an emission source of interest in an emission plume is provided. The method involves measuring airborne matter at one or more than one identified locations using an optical sensing instrument (OSI) operatively connected with one or more than one matter samplers and mounted on a vehicle. The one or more than one airborne matter samplers are passed through an airspace to be sampled, and one or more concentration measurements are obtained. Geographic positions and altitude values for each of the one or more identified locations are established, and a point concentration measurement for the airborne matter for each identified location determined. The concentration measurements are mapped relative to the geographic position and altitude values for each of the one or more identified locations to obtain an airborne matter concentration distribution map in one or more measurement surfaces through a cross-section or profile of the emission plume.

Abstract: The present invention relates to a method for reconstructing protein database for identifying a protein and a method for screening a protein using the same, more precisely a method for reconstructing protein database, and a method for identifying a protein using the same. The method for reconstructing protein database and the method for identifying the protein of the invention are very useful for the investigation of endogenous proteins and their functions and interactions, and are further effectively used for the development of diagnostic and therapeutic agents for various diseases.

Abstract: A device for processing measurement data assigned to a measurement on a fluidic sample to be separated, the measurement data having multiple features being indicative of different fractions of the fluidic sample, the device includes a feature position analysis unit configured for analyzing positions (p1, p2, d1, d2) of at least a part of the features relative to one another, and a display adjustment unit configured for adjusting, based on a result of the analyzing, a mode of displaying at least a part of the features along at least one display axis of a display diagram so that at least a part of adjacent features is positioned equidistantly along the at least one display axis or so that at least a part of adjacent features is positioned to have a distance (d) from one another which is larger than or equal to a predefined threshold value (dth).

Abstract: A method for matching a precursor ion with one or more related product ions includes providing input data sets obtained from sample injections, each of the data sets including a precursor ion and one or more product ions, normalizing the input data sets in accordance with a single retention time for the precursor ion, determining which product ions are within a predetermined retention time window with respect to the single retention time, and, if a product ion is within the predetermined retention time window for a specified number of the input data sets, determining that the product ion is related to the precursor having the single retention time. An apparatus for analyzing a sample includes a chromatography module, a mass-spectrometry module in communication with the chromatography module, and control unit in communication with the chromatography module and the mass-spectrometry module.

Abstract: A method of calculating the carbon or greenhouse gas footprint of a food composition includes determining the CO2 or greenhouse gas emission of each ingredient by associating a total energy value with the ingredient, determining the proportion of the total energy value contributed by each of at least one energy source, where each energy source has a characteristic CO2 or greenhouse gas emissions value, and then calculating a CO2 or greenhouse gas emission value for the ingredient based on the GHG emission values of each contributing energy source. Also, optimizing the CO2 or greenhouse gas emissions in the formulation of pet food employs this method.

Abstract: A measurement instrument having a processor, a first sensor and a second sensor. The processor is adapted to output a measurement signal embodying a measurement of a physical quantity. The first sensor and second sensor are connected to the processor and are operable to generate respectively first and second measurements of the physical quantity. The processor defines a first measurement range within which the measurement signal is dependent on the first measurement and not the second measurement. The processor defines a second measurement range within which the measurement signal is dependent on the second measurement and not the first measurement. The first and second ranges meet at a predetermined transition. The first and second measurements are different at the transition and the measurement embodied in the measurement signal crosses the transition without an abrupt change.

Abstract: Absolute quantitation of protein in a sample is provided by comparing a sum or average of the N highest ionization intensities observed for peptides of a particular protein along with a calibration standard. The calibration standard can be in the form of a table generated by prior protein peptide analysis performed using one or more pre-determined proteins. The comparison is used to determine a corresponding absolute quantity of protein based on the observed sum or average of ionization intensities. A simple conversion factor can be applied to the calibration standard value to determine the absolute quantity of protein in the sample.

Abstract: A method for calibrating a flame ionization detector (FID). The method includes receiving a request to schedule a calibration. After scheduling the calibration, a flow request command is sent to a gas distribution system at a scheduled calibration. The flow request command instructs the gas distribution system to provide a gas at a gas concentration level to the FID. After the gas distribution system provides the gas at the gas concentration level to the FID, the method includes receiving a raw count from the FID and correlating the raw count with the gas and the gas concentration level provided to the FID. The method then stores the results of the correlation in a calibration log.

Abstract: Sensor devices and sensing methods are provided. A sensor device is provided two flow channels, each comprising a sensor, and analyte flow is alternated between the two channels such that the sensors alternately serve as a sensor and a reference, thereby increasing accuracy of the sensors. The device is useful, for example, in chemical sensing using a variety of sensor types including without limitation: chemiresistors, gravimetric sensors, optical sensors, among others. Related sensing methods also are provided.

Abstract: The method of the present invention provides a fast, robust, and automated multivariate statistical analysis of gas chromatography/mass spectroscopy (GC/MS) data sets. The method can involve systematic elimination of undesired, saturated peak masses to yield data that follow a linear, additive model. The cleaned data can then be subjected to a combination of PCA and orthogonal factor rotation followed by refinement with MCR-ALS to yield highly interpretable results.

Abstract: A temperature of a gas sensor may be adjusted to a first temperature value for a first period of time and a second temperature value for a second period of time. A signal of the gas sensor may be measured during the first period of time to determine a first signal value and during the second period of time to determine a second value. Then, concentration information for at least one gas is calculated according to the first signal value and the second signal value. While the gas sensor signal may include information about a presence of a first gas and a second gas, the concentration information for the at least one gas may not substantially include concentration information for the second gas.

Abstract: A method for improving the chromatographic detection limit for an analyte including a) producing a chromatogram with a peak of the analyte, b) calculating a regression straight line for a baseline from measured values of a section without a peak in the chromatogram, c) calculating a regression function from measured values of the peak of the analyte, d) subtracting the regression function from the chromatogram, e) calculating a regression polynomial for the baseline from the values of the chromatogram which have been changed in step d), calculating a further regression function from the measured values of the peak in the produced chromatogram, g) calculating a peak area between the regression polynomial and the further regression function, h) repetition of step d) with the further regression function instead of the regression function and of steps e), f) and g), until the calculated peak area changes by less than a predetermined amount.

Abstract: A system and method for measurement of radioactivity concentration of a radiopharmaceutical are disclosed. The radiopharmaceutical may be a radioactive tracer solution including a tracer solution and a buffer solution. The system may include a vial that receives the tracer solution and the buffer solution; a scale; a radioactivity measuring device; and a controller that determines the radioactive concentration based on a measured radioactivity of the tracer solution and the buffer solution in the vial, and a weight of the tracer solution and the buffer solution in the vial. The method may include the steps of (1) transferring the tracer solution into a vial; (2) measuring a radioactivity of the tracer solution in the vial; (3) determining a weight necessary to achieve a desired radioactivity concentration; and (4) diluting the tracer solution in the vial to the determined weight with a buffer solution.

Abstract: A mass spectrometry apparatus configured to allow a user to designate an upper limit value UL together with a lower limit value, as a peak sorting condition. A data processing section is operable to determine whether respective peak intensities of a plurality of peaks appearing on a mass spectrum fall within an intensity range Ath defined by upper and lower limit values UL, LL, and exclude any peak out of the intensity range Ath. The remaining ions are selected as precursor ions, for example, in descending or ascending order of peak intensity so as to perform an MS2 analysis. The upper limit UL is adequately set to allow the MS2 analysis for a sample component with a low concentration, by priority, while avoiding a sample component exhibiting a high intensity and having no need for the MS2 analysis.

Abstract: Methods and apparatus for providing data processing and control for use in a medical communication system are provided.

Abstract: Products and processes are provided herewith for analyzing octane content in a fuel sample that include the step or steps of receiving an octane measurement of a fuel sample from a octane analyzer, rounding the octane measurement to a nearest recognized octane rating, comparing the rounded octane measurement with a listed octane rating for the fuel sample, and communicating results of the comparison to a user of the octane analyzer. The octane analyzer may be incorporated into a fuel pump or a vehicle. The results of the comparison may also be used to adjust the vehicle operating parameters to account for the actual octane rating of the fuel dispensed into the vehicle.

Abstract: A chromatograph analyzing device for automatically executing a base line setting process on an unseparated peak using preset base line conditions. The chromatograph analyzing device includes a separation unit for separating a component included in a sample, and a data processing device for identifying the component of the sample and the quantity of the component in the sample by using a chromatogram obtained from the separation.

Abstract: Method and system for estimating a growth stage of an alga in an ambient fluid. Measured light beam absorption or reflection values through or from the alga and through an ambient fluid, in each of two or more wavelength sub-ranges, are compared with reference light beam absorption values for corresponding wavelength sub-ranges for in each alga growth stage to determine (1) which alga growth stage, if any, is more likely and (2) whether estimated lipid content of the alga is increasing or has peaked. Alga growth is preferably terminated when lipid content has approximately reached a maximum value.

Abstract: Systems, methods and apparatus relating to evaluation of alumina feedstocks are disclosed. A system may include an alumina storage unit comprising an alumina feedstock, an alumina supply member in communication with the alumina storage unit and an aluminum electrolysis cell. The alumina feedstock of the alumina storage unit may periodically flow through the alumina supply member and to the aluminum electrolysis cell. A measurement device may be in communication with the alumina supply member, and may be configured to measure a supply member property and transmit a first signal to a processor. The processor may be configured to receive the first signal and produce supply member property data based, at least in part, on the first signal.

Abstract: A process of determining whether a patient with a disease or disorder will be responsive to a drug, used to treat the disease or disorder, including obtaining a test spectrum produced by a mass spectrometer from a serum produced from the patient. The test spectrum may be processed to determine a relation to a group of class labeled spectra produced from respective serum from other patients having the or similar clinical stage same disease or disorder and known to have responded or not responded to the drug. Based on the relation of the test spectrum to the group of class labeled spectra, a determination may be made as to whether the patient will be responsive to the drug.

Abstract: From the data obtained by an LC/MS analysis in which an automatic MSn analysis is performed, all MS2 spectrum data are collected (S1), and a data matrix is created whose elements are peak intensity data with different precursor ions being arrayed in the horizontal direction and the mass-to-charge ratio of the product ions in the vertical direction (S2). By using the data in this data matrix, the correlation coefficients between two precursor ions are computed to create a correlation coefficient matrix (S3). In the correlation coefficient matrix, the diagonal elements whose value is “1” are all replaced by “0” to create an adjacency matrix (S4). A network analysis is performed for the adjacency matrix to create a network map showing the correlations among different precursor ions (MS2spectra) (S5).

Abstract: In a multiplexed assay, each molecule of a plurality of molecules is attached to a support matrix with a substrate adapted for attachment and/or synthesis of molecules and an integrally-formed memory device with an optically-encoded identifier to uniquely identify the molecule attached to the substrate. The molecules are exposed to one or more processing conditions then placed within the path of an optical detector adapted to read the optically-encoded identifier and measure biochemical processes on each support matrix. The support matrices may besingulated to be read by the optical detector one at a time.

Abstract: A method for registering a content change in a fuel system of a motor vehicle, where the fuel system is configured to receive a first fuel and a second fuel into a common space. A first condition is correlated to receiving the first fuel, and a second condition is correlated to receiving the second fuel. The method comprises admitting fuel to the fuel system and indicating that the first fuel has been admitted if a condition responsive to admitting the fuel matches the first condition and does not match the second condition.

Abstract: A universal method for jointly measuring surface property parameters of a material comprises the following steps: performing saturation processing on a surface of a material to be measured; mixing the material to be measured which has been processed by saturation with an indicating electrolyte solution; after the mixture solution achieves an balance by ion exchange, measuring the balanced concentration values of positive ions of the indicating electrolyte and H+ in the mixture solution; according to the balanced concentration values of positive ions of the indicating electrolyte, calculating surface potential of the material; and according to the surface potential of the material, calculating specific surface area and surface charge density of the material; according to surface charge density of the material, calculating surface electric field intensity; according to surface charge density and specific surface area of the material, calculating total surface charge of the material.

Abstract: A computerized method and system for determining engine exhaust emissions for a job. Job utilization data is stored for each of a plurality of engines used for the job. An amount of engine exhaust emissions for each engine is determined based on the utilization data. An amount of engine exhaust emissions for the job is determined based on the amount of engine exhaust emissions for each engine. The amount of engine exhaust emissions for the job is stored and may, for example, be used for determining job cost, reporting, or controlling the job in real-time.

Abstract: Methods and sensors for selective fluid sensing are provided. A sensor includes a resonant inductor-capacitor-resistor (LCR) circuit and a sensing material disposed over the LCR circuit. The sensing material includes a coordination compound of a ligand and a metal nanoparticle. The coordination compound has the formula: (X)n-M, where X includes an alkylamine group having the formula (R—NH2), an alkylphosphine having the formula (R3—P), an alkylphosphine oxide having the formula (R3P?O), an alkyldithiocarbamate having the formula (R2NCS2), an alkylxanthate having the formula (ROCS2), or any combination thereof, R includes an alkyl group, n is 1, 2, or 3, and M includes the metal nanoparticle of gold, silver, platinum, palladium, alloys thereof, highly conductive metal nanoparticles, or any combination thereof. The sensing material is configured to allow selective detection of at least six different analyte fluids from an analyzed fluid mixture.

Abstract: By using information collected on-site, estimation of a damage area at that time and also prediction regarding subsequent expansion of a disaster-affected area are performed.

Abstract: A measuring system precisely for measuring the density of a medium flowing in a pipe line. The measuring system comprises a temperature sensor and a pressure sensor. Both sensors communicate with measuring electronics of the system. The measuring electronics are operable to provide, based on temperature measurement, pressure measurement, and a numerical compensation factor a density measured-value, representing, a density of the flowing medium at a virtual density measuring point. The compensation factor corresponds with a locational variability of at least one thermodynamic variable of the medium, occurring along the flow axis of the measuring system and/or a locational variability of the Reynolds number of the flowing medium along the flow axis of the measuring system.

Abstract: A chromatograph mass spectrometer is provided for obtaining the information pertinent to a structural analysis, with a simple operation, on a compound series including a plurality of compounds whose structures and characters are similar. First, based on the data obtained by a normal LC/MS analysis, a two-dimensional isointensity line graph is created and displayed with a retention time and a mass-to-charge ratio on the two axes and with a signal intensity represented in contour (S1 and S2). When the operator specifies a desired range by a drag operation or the like by a mouse (S3), peaks included in the range specified are extracted and based on the peaks, precursor ions are selected (S4 through S6). Then a schedule is created so that an MS2 analysis is performed for the precursor ions selected in the course of an LC/MS analysis for the sample to be targeted (S7).

Abstract: The invention features compositions and methods that are useful for precisely determining the amount of one or more analytes present in a sample. In one aspect, the invention provides a composition for measuring the abundance of one or more target analytes in a sample, where the composition contains a set of detection units for each analyte fixed to a substrate (e.g.,a membrane, bead, filter, chip, polymer-based film or glass slide, or other printable surface), where each detection unit contains a discrete amount of a capture agent that specifically binds the target analyte, and the amount of capturing agent varies over the set to form a concentration gradient.

Abstract: A new method is presented for characterizing the associative properties of a solution of macromolecules at high concentration. Sample aliquots spanning a range of concentrations are injected sequentially into a light scattering photometer. Equilibrium association constants and association stoichiometry are derived from an analysis of the angular and concentration dependence of the scattering signals. Thermodynamic nonideality, which becomes important at high concentrations, is dealt with in the analysis in a simplified manner which is applicable to multiple associated species.

Abstract: A method and apparatus for acquiring data from a mass spectrometer and its transmission to a computer system including a data acquisition engine, a network interface and a throughput optimization module which includes a ring buffer and a protocol stack. A compression engine may be provided between the acquisition engine and the ring buffer. The ring buffer is configured as a number of segments containing portions of memory matching the size of data words from the acquisition engine. When a segment is full of data corresponding to the words, or is partially full and has received data containing an end of scan marker, the number of words in the segment is written into a header word in the segment and the data in that segment are moved to the protocol stack. Subsequent data is received by the next segment in the buffer.

Abstract: A nuclear quadrupole resonance system which senses the stimulated emission from target molecules includes in a calibration step and a stimulated emission response detection step, with the system employing clutter cancellation involving linear regression and the use of cross correlation with a series of known molecular signatures, both increasing the signal-to-noise ratio of the system.

Abstract: A method for characterizing a sample containing at least one compound is disclosed. Initially, a three-dimensional set of data is generated through sample analysis using time resolved and mass resolved separation techniques. The data comprises at least one signal as a function of a mass variable over a first range of measurement and of a time variable over a second range of measurement. The first range of measurement is divided into at least two mass variable intervals, and for each mass variable interval, an extracted signal is selected which is a function of the time variable. The second range of measurement is divided into at least one time variable interval. A characteristic value is then selected for each time variable interval and each extracted signal to generate a characteristic sample profile, comprising one or more characteristic values as functions of respective time variable intervals and respective mass variable intervals.

Abstract: A system for predicting a source location and release rate of a hazardous substance uses the basic knowledge of meteorological information (wind speed, direction, and stability) and two or more concentration measurements of the chemical released. Horizontal dispersion information obtained from surface meteorological data at sensor locations are used to narrow the search domain for the release location, reducing the computational cost. Each of the possible release locations in the search domain and possible release rates are evaluated in a process that predicts a concentration measurement at a sensor, based on a predicted location and release rate. The location and release rate that results in a least error when compared to an actual concentration measurement at the sensor are chosen as the source of the chemical and the release rate from the source.

Abstract: This disclosure relates generally to a sampling device, and more particularly, a sampling device that facilitates spectroscopic measurements with a variable path length and the necessary software controlled algorithms and methods for such a device.

Abstract: Methods and systems are provided that utilize measured isotopic abundance data to correlate a product to the synthesis process by which it was made. By utilizing the principles described herein, isotopic process profiles for synthetic products can be constructed, products of unknown origin can be inferentially identified to the processes by which they were made, and synthesis processes can be monitored for consistency of process parameters.

Abstract: When a target substance's composition formula is deduced by using a mass spectrometer, if the target substance's composition formula is deduced based on an MSn spectrum and candidates are found, a composition formula candidate list including all the composition formula candidates is created, and the list is displayed in a list format. The composition formula candidates are narrowed down based on the MSn spectrum by an MS2 analysis or MS3 analysis. If there is a candidate to be excluded, the composition formula candidate list is updated, and the excluded candidate is moved to the exclusion list. Accompanying this, a composition formula candidate table is displayed in a list format on the display window. In this table, the composition formula candidates included in the exclusion list and the remaining composition formula candidates in the composition formula candidate list are simultaneously displayed with different colors so that they are visually discriminable.

Abstract: Naturally present chloride concentration in natural water is utilized for the development of the technique to gauge the performance of percolation tanks in space and time. The chloride mass balance technique is simple, sensitive, reliable and yet powerful enough to resolve the temporal variation due to the effect of silting or climate factors. The percolation efficiency data of percolation tanks can aid in the formulation of guidelines for selection of suitable sites for future tanks with greater efficiency. Otherwise unscientific construction of percolation tanks in sites that yield poor percolation efficiency is uneconomical, and the very purpose of their construction will be forfeited. Thus the technique developed using chloride mass balance in tank water for evaluation of tank performance is highly economy oriented.