Compensation
The measurement of Outflow with compensation of Temperature and Pressure the measurement of fluid outflow is each time more requested by the industries. In many industrial processes, it is important and it also needs compensations for its real indication and totalling. In the market, it has an enormous variety of types of outflow measurers, since simplest until most sophisticated, for the most diverse applications. The type to use always will go to depend on the fluid, its physical state (liquid or gas), on the characteristics of resolution, exactness and of the trustworthiness required amongst other factors. In this article we go to present an operation principle and the commentaries on a measurement system that functions distinguishing compression and possesss compensations of temperature and pressure.
To nowadays verify the degree of importance of the measurement of outflow, we have the example of the Brazil-Bolivia gas-line that carries natural gas from Bolivia until So Paulo. In this gas-line it is carried up to 20 million cubical meters per day of natural gas. Esteem a cost of sales of U$ 0,50 for cubical meter, one sees that a bias quality control of only 1% in an outflow measurer is associated with an amount of about U$ 100,000 per day. The correct choice of a system of measurement of outflow depends on the exactness desired for the measurement, of the conditions of the levels of pressure and temperature in which the system will have to act. A system of measurement of outflow using the beginning of the distinguishing pressure with orifice plates still is one of the methods with bigger application involving transport of fluid and gases.
This use well is spread and if it must to the following factors: the simplicity and low cost of installation, easy maintenance for the measurement elements and low values for measurement uncertainties. With the measurement of outflow for distinguishing pressure compensated in pressure and temperature, calculating of outflow it will have to offer three entrances that can be used for linking with standardized analogical signals proceeding from the sensors of distinguishing pressure, gauge pressure and of temperature, having to possess the feeding of 24 Vcc for transmitter the two wires. The totalling of the outflow corrected with counting of 8 digits must be presented the indications of the three entrances through 5 digits and also be carried through, beyond making use of for the panel frontal or by means of external dry contact of reset. Important characteristics for attainment of the correct indication go since the adoption of factors of compressibility of the fluid in the conditions of reference and operation, passing for the density and the pressure of reference in absolute value. The option of linearizao of the signal of the entrance of the outflow is used for better exploitation of all the indication points, that will have to be express in units configured (m3/h; l/h; l/min ; l/s; kg/h; ton/h).
Tags: Technology