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Stand for verification and calibration of level measuring instruments ElMetro-SPU
Stand for verification and calibration of level measuring instruments ElMetro-SPU is intended for reproduction of a length unit during level measurement, simulation or direct measurement of liquid level. ElMetro-SPU is applied for verification, calibration, graduation and testing of radar, float ball, ultrasonic, radio wave level meters, level meters with coaxial probe and etc.
Stand corresponds to the 1st or 2nd class in accordance to GOST R 8.660-2009.
Device description and working principle:
Working principle of the stands is based on simulation of level measurement in a horizontal plane. The reflective target mounted on a movable part of the stand moves at a set distance which is measured by reference distance measuring instruments with high precision.
In dependence on selected stand type, metrology stand ElMetro-SPU provides direct liquid level measurement or simulation of level measurement to reproduce level units. Ranging lasers or magnetic linear displacement transducers could be applied as measuring instruments for the stand.
Type G (direct liquid level measurement) of the stand consists of (view Pic. 1) two vertical measuring tubes (a metal one with diameter not less than 100 mm and a glass one with diameter not less than 14 mm) which are filled with working fluid and communicate with each other. Verified instruments are mounted to an immovable base which is placed in the upper part of the stand, whereas a movable base could travel on the linear part of the stand along its measuring tubes. A device which registers fluid level in the glass measuring tube by meniscus is located on the movable base. Equipment for measuring distance between movable and immovable bases of the stand is mounted on its linear part.
A, B,C, D, E and F models of the stand consist of a horizontal linear part (view Pic. 2), a fixed base (view Pic. 3) and a movable base (view Pic. 2) which imitates changes in level and measurement & data collection system.
Immovable base is a mounting plate intended for rigid mounting of various level measuring instruments. Stand construction ensures a level meter is installed in such a way that mounting flange surface of the level meter is perpendicular to the linear part of the stand.
Linear stage, which is presented by metal profiles mounted on supports, provides linear motion of a movable part at a preset distance. Location of the movable part of the stand in relation to immovable part is defined by one of measuring instruments listed in Table 1.
Movable base of the stand is a stage which could travel along linear part of the stand. In models with a linear-displacement transducer movable part of the stand is equipped with a precise servomotor which ensures its motion. In models with a ranging laser movable part of the stand is moved manually.
Stand control system carries out data collection and its display in the screen of a personal computer as well as control movable part of the stand if it is equipped with a linear-displacement transducer. Data collection and displacement of a movable part are executed by means of specialized software.
Stand software (hereinafter referred to as “software”) is installed on a stand control system PC. Software provides general control of the stand operation, automatic collection and mathematical processing of measurement results as well as data archiving. Data exchange between PC and movable part of the stand is enabled by Modbus RTU protocol.
Measured data analysis software is based on modularity principle. Software provides an opportunity to store test results and data about verified level meter in archives with reference to its serial number. In order to prevent intended or unintended interference with stand operation, the software is fit with a two-level password protection system with division of user rights.
Technical characteristics:
Technical characteristics of ElMetro-SPU stand in dependence on its model are listed in Table 1 below.
Stand model Level unit reproduction method Measuring instrument type Reproduction resolution of level unit, mm Limit of permissible absolute error of level unit reproduction, mm Maximum upper limit of level unit reproduction, m Table 1. Technical characteristics of ElMetro-SPU stand A Simulation of liquid level measurement Linear displacement transducer 0.05 ± 0.3 30 B ± 1.0 30 C ± 1.0 15 D ± 1.5 20 E Ranging laser 10 ± 1.0 10 F ± (1+2.5·10-2·L), where L is an upper limit of level unit reproduction, m 30 G Direct level measurement Linear displacement transducer 1 ± 1.0 6 Weight and overall dimensions of ElMetro-SPU stand are listed in Table 2 below.
Stand model Level unit reproduction method Maximum overall dimensions, m Maximum weight, kg Table 2. Weight and overall dimensions of ElMetro-SPU stand A Simulation of liquid level measurement Length from 4.5 to 17; width 4; height 2 from 500 to 3000 B Length from 4,5 до 32; width 4; height 2 from 500 to 1500 C Length from 4,5 до 17; width 4; height 2 from 500 to 2000 D Length from 4,5 до 22; width 4; height 2 from 300 to 1000 E Length from 4,5 до 12; width 4; height 2 from 300 to 1000 F Length from 17,5 до 32; width 4; height 2 from 1500 to 3000 G Direct level measurement Length from 2 до 7; width from 1 to 2; height from 2 to 7 from 300 to 1500 - Stand corresponds to a reference stand of the 1st or 2nd class in accordance to GOST R 8.660-2009.
- Automatic and manual modes of verification/calibration of level measuring instruments.
- Electric supply parameters:
- voltage: 220 V;
- power consumption: not more than 2 kW.
- Ambient temperature range: from +15 to +25 ºС.
- Verification interval: 1 year.
- Listed in National register of measuring instruments no. 56506-14.
Verification of level meters with coaxial probes:
Stand model for verification of level meters with coaxial probes is different since liquid levels in two communicating cylindrical vessels are set directly. Liquid level in one of them is measured precisely, whereas verified level meter is installed in another one. Liquid filling control system ensures that required level is maintained.
Upper limit of level unit reproduction range depending on reproduction method:
- simulation of level unit measurement: up to 30 meters;
- direct level measurement: up to 6 meters.
Limit of permissible absolute error for measurement unit reproduction in dependence on reproduction method:
- simulation of level unit measurement: ± 0.3 mm or ±1.0 mm;
- direct level measurement: ±1.0 mm.
Supply package:
Standard supply package of ElMetro-SPU stand for verification and calibration of level measuring instruments includes: stand (1 pc.), product certificate (1 pc.), manual instruction (1 pc.), verification procedure description (1 pc.), connection kit (1 set), a set of spare parts (1 set), tools kit and accessories (1 set) and software ElMetro-Level (1 pc.).
To make enquiry and get a commercial offer on ElMetro-SPU stand of the Russian manufacturer ElMetro company, please, send us product order code (view manual instruction) to e-mail: info@elmetro.ru or contact us via tel.: +7 (351) 220-06-01. To discuss technical questions, please, refer to technical support tel.: +7 (351) 220-06-03