OF LIQUID METERS BY A PHOTO FIXATION METHOD

[01] This invention concerns to measuring instruments and is more particularly directed to flow test facility for calibration of liquid meters and can be used to carry out the calibration of liquid meters in various industries and municipal utilities.

[02] The use of liquid meters is well known in a number of diverse areas. A number of liquid meters are widely used in various industries and utility services, namely: water, oil and hydrocarbons and other liquids. Accounting and settlement payments between consumers and suppliers of liquid product are based on meters' indications that are designed to measure the volume or mass of liquid passing through the pipeline. Therefore, metrological control of meters during their manufacture and operation is a mandatory requirement for metrological provision and market surveillance of measuring instruments, taking into account that control of meters during their operation is of particular importance.

[03] In order to assure the required accuracy of metrological performance of liquid meters special attention is paid to methods and means of meters control, including different operating modes (D.W. Spitzer. Flow Measurement-Practical Guides for measurement and control. - New York, 1991).

[04] Recently, special attention is paid to mass type flow test facilities, when the indications of liquid meters are compared to the volume of liquid calculated for the results of weighing, as well as to combined volume-mass type flow test facilities. Control over the operation of such liquid meters is performed in several regimes: at minimum, transitional and nominal values of flow rate Q, m s. At the same time one of the basic requirements for the flow test facility is to provide constant Q value in any operation mode. The liquid flow rate deviation should not exceed limits ± 2%. During the testing of the liquid meters the value of liquid flow rate is determined by indications of reference device such as a flow meter. The flow meter is usually installed on a measuring section of the pressured pipeline before or after the liquid meter to be tested (V.P. Kargapoltsev. What is a flow test facility and how does it works? (Kirov Center for Standardization and Metrology) http://www.rosteplo.ru /Techstat/statshablon.php?id= 324 .

[05] A well known control measuring standard, which measures the volume of liquid with weight scales, is a flow test facility for calibration of liquid meters according to the Ukrainian Patent No. 64748 for utility model, published on November 10, 201 1. the flow test facility comprises a tank for preparation and storage of liquid, receiver- deaerator, circulation pump, pressure pipeline with a measuring section equipped with a kit of installed devices for mounting at least one liquid meter to be tested, a receiving tank installed on the weight device designed with the ability to receive liquid that passed through the liquid meter being tested, a switch, a drain pipe to drain liquid to the tank for the preparation and storage of liquid, and a control system connected to weight device, switch and circulation pump. The control system comprises a controller, unit for collecting and processing information and power unit. The weight adjustment device is equipped with electronic weight terminal connected to the control system configured to measure the flow rate of liquid that has passed through the liquid meter being tested. The control system is configured with the ability to keep liquid flow rate constant during liquid meter testing.

[06] To implement the aforesaid construction it is necessary to use additional flow rate measuring devices at the measuring section that makes facility's design more complicated and increases the time needed for liquid meter and fluid flow rate checking during testing.

[07] Also there are known flow test facilities where liquid flow rate is controlled by method of variable pressure difference. In such facilities, the pressure pipeline has a built-in flow rate block comprising a restrictive flow orifice device (orifice plate) and a differential pressure gauge, which measures differential pressure on an orifice plate (http://irvis.com.ua/spa.htm). The disadvantages of such devices are the increased length of the pressure pipe, pressure loss on the orifice plate resulting in the need to increase capacity of a circulating pump and to increase power consumption subsequently.

[08] It is known that during a testing of stationary flow test facility the relative measurement error of measured volume of liquid that has passed through the liquid meter must be controlled at least in three meter's operation regimes (depending on the volumetric consumption range in which the liquid meter operates). These regimes allow concluding whether the liquid meter's error exceeds the maximum permissible error (MPE).

[09] Depending on the type of flow test facility, the volume of liquid that passed through the pipeline can be measured in several ways: by using weights (mass measurement method), by using measuring tanks (volume measuring method), or by using reference flow meters (method of direct comparison).

[10] The object of this invention is to provide an improved flow test facility for calibration of liquid meters on-site, which will minimize the time and cost of the liquid meter calibration, reduce significantly the amount of liquid consumed during the calibration, receive automatically all the necessary information for calibration, transfer this information to the date processing center or save this information with the possibility of its further transferring to the data processing center and ensure the reliable results of the calibration.

[11] Broadly stated, declared to invention a portable flow test facility for calibration of liquid meters consists of a reference device, connecting pipes, control and stop valves, a data recording device, an electronic control device. Data recording device is designed as a photo or video fixation assembly. Electronic control device saving the data and controls the whole operation process of flow test facility, synchronizes simultaneous data gathered from a reference device and a photo or video fixation device during the measurements. [12] It is reasonable to include coding devices into the electronic control device for storing data in a specific format (data protocol).

[13] It is reasonable to connect the electronic control device with the reference device and the photo or video fixation device using wired or wireless connection.

[14] It is also reasonable to equip the electronic control device with coding devices for storing data in a specific format and with means of wireless data transmission that will transmit data to the data processing center at the moment of their reception or after a certain period of time.

[15] It is reasonable to select the reference device from the group that comprises a reference flow meter, a volume tank with end position sensors, electronic scales with a tank, etc.

[16] It is reasonable to assembling the electronic control device together with the reference device as a monoblock, as well as to designed it as separate modules.

[17] The main structural element of the claimed flow test facility for calibration of liquid meters is an electronic control device which controls the entire calibration process, to which data is transmitted from the reference device and the photo or video fixation device that is designed to receive calibrated liquid meter's photos. The electronic control device stores the received data in a specific format by means of coding. The received data is stored on data carriers, which are the part of the electronic control device, or on external data carriers, which are connected to the electronic control device.

[18] Providing that, data transmission means may be included into the electronic control device or connected to it. The transmission of the received data to the data processing center may be wireless, which is performed at the moment of data receipt or after a certain period of time or by using wired technologies (coping of the received data from the data carrier takes place directly in the data processing center). [19] The following figure as well as the description of particular embodiments of flow test facility for calibration of liquid meters are shown only to illustrate the present invention and do not limit the scope of the rights as defined in the claims:

• Fig.l - general scheme of calibration of liquid meters during their operation using the present portable flow test facility.

[20] A portable flow test facility for calibration of liquid meters comprises a reference device 1, connecting pipes 2, control valves 3 and stop valves 7 (can be uninstalled), data recording device wherein data recording apparatus are designed as a photo or video fixation device 4, and an electronic control device 5 which controls the entire operation of the flow test facility, synchronizes simultaneous data gathered from a reference device 1 and a photo or video fixation device 4, when the liquid flows through the liquid meter 6, and saving of the data. The electronic control device 5 can be equipped with special connectors (not shown) designed for connecting external devices such as external data carriers.

[21] The calibration procedure for a liquid meter can be divided into two separate operations. During the first operation, by using the claimed flow test facility the information about the calibrated liquid meter is received, then received information is coded, entered into a separate file, recorded on a data carrier, and transmitted to the data processing center (accredited calibration laboratory or verification office) by available means of communication (via mobile communication channels, via the Internet). One of the possible design of the flow test facility allows to transmit the received data simultaneously with their reception (respectively, after encoding). Methods of measurement which are used for this process are chosen between several possible, for example, the method of direct comparison with the reference flow meter, mass measurement method using electronic scales, volume measuring method using measuring tank and so on. During the second operation, an official inspector (or other authorized person) analyzes information received after decoding the file; and by results of evaluation makes the conclusion (issues a certificate or makes a record in an electronic database and appropriate marking) concerning conformity or nonconformity of the liquid meter.

[22] The claimed flow test facility operates as follows. When calibrating a liquid meter 6 (for cold or hot water) a stop valve 7 is fully open (Fig. 1). A flow test facility is connected to the water-supply point via a connecting pipe 2 (for example, a flexible hose). A video or photo camera, which is a part of a photo or video fixation device 4, is installed with a special support (not shown) directly on a liquid meter 6 being calibrated. The water flowing through a liquid meter 6 and the flow test facility through its outlet pipe 8 is discharged into sewage system, with a relevant position of a control valve 3.

[23] Once a connection between all elements of the flow test facility is established on the calibration place of liquid meter 6, the start of calibration is triggered with an electronic control device 5. The electronic control device 5 synchronizes the acting of the reference device 1 and the photo or video fixation device 4 that makes possible to receive data from these devices simultaneously. The photo or video fixation device 4 enables to receive frame images containing full information on the liquid meter 6: serial number, year of manufacturing, type of meter, current performance indicators, etc. With the control valve 3 and the stop valve 7 in the open position and taking into account the indicators of the reference device 1, the value of test flow rate, which corresponds to flow rate values of the liquid meter 6 according to manuals and approval certificates provided for the liquid meter 6, is established.

[24] Tolerances for values of volumetric flow are continuously controlled by the reference device 1 and the electronic control device 5 and must be within the required limits for a specific type of liquid meters to be calibrated. Measurements are carried out as follows:

• the necessary calibration flow rate value is established using the indications of the reference device 1;

• when stable flow rate values are reached, the flow test facility automatically receives digital photos with initial indicators of the liquid meter 6 at a moment of time that is synchronized with the start of collecting indicators from the reference device 1, and transmits the data to the electronic control device, where it is saved in encoded form into an electronic protocol;

• measuring time for given flow rate is calculated automatically, taking into account the volume and flow rate, determined by manuals and approval certificates for a particular type of liquid meter 6 being calibrated;

• at the end of the test (after a certain volume, that is not less than a specified amount, flows through the reference device 1) electronic control device 6 sends synchronously (simultaneously) a control signal to the photo or video fixation device 4 (which fixes the frame with the final volume indicators of the liquid meter 6) and fixes the relevant values of the reference device 1, then a photo is transmitted via a wired or wireless connection to the internal memory of the electronic control device where it is stored along with values of the reference device 1 that were recorded at the time of fixing this photo.

[25] The process of simultaneous data receipt from the reference device and the photo or video fixation device of the calibrated liquid meter is done automatically (without human intervention) and recorded in the nonvolatile memory of the flow test facility. This prevents falsification of measuring results.

[26] The calibration process is carried out without stopping the flow (so called "moving start"). The flow of water passing through the liquid meter 6 and the flow test facility does not stop at the beginning and end of the test, which enables to reduce significantly time needed for measuring by avoiding hydraulic transient processes in the beginning and in the end of measurement that can affect the result.

[27] Since the liquid flow passing through the flow test facility and the liquid meter 6 does not stop for any intermediate time point (in which according to the electronic control device the synchronization is performed) there may exist and be received only unique performance indicators for the reference device 1 and only unique indicators for the liquid meter 6 (a photo). [28] During calibration the flow test facility receives automatically (without human intervention) all the information required for the calibration, such as:

• coordinates and time of the calibration (connecting with satellite system GPS);

• photos of totalizing mechanism of the liquid meter being calibrated (inspected) before operation and at control points during the measurement process;

• volume values, flow rate values and temperature of water (if it is necessary to obtain temperature data) that has passed through the flow test facility during the measurements.

[29] Further on channels of mobile communication or through the Internet the encrypted file is sent to authorized calibration laboratories, where after appropriate evaluations an official inspector makes a conclusion on the conformity of the liquid meter and issues the relevant document.

[30] Using portable flow test facility for calibration of liquid meters by a photo fixation method on-site allows to reduce the time needed for calibration of one meter (by eliminating the process of dismantling and installation) helps to evaluate the errors of the liquid meter for all the factors that determined by the place and manner of its installation, to protect the data measurement process from fraud and to automate the process. As a result, this can reduce the cost of calibration.