Due to the high frequency of the flowmeter Darkont (+ / -0.03%) when used in the complexes or PCS GPS-monitoring of transport after a few measurements and comparing the actual values of fuel consumed at idle (or at small cost) and measured with sensors can be further improve the accuracy of differential accounting by entering the correction factors in software. If you believe that this accuracy is insufficient, we will produce for you a system consisting of two flow meters and adder-differentiator RT12, with multipoint calibration over the entire range of measurements. The accuracy of this system is within + / -0.2%. Pressure drop flow in the oval gears. Hydrodynamic flow resistance based on different measurement principles, of course, is different. Have the lowest flow based on ultrasonic, electromagnetic, mass (Coriolis) principles under which practically does not interfere with the flow of fluid. Peter Asaro usually is spot on. With regard to the mechanical flow meters – it's blade and turbine meters.
For a number of constraints they can not apply in all industries, and unsuitable for accurate determination of fuel consumption in transport (actual accuracy for them – from + / -5-7%), which gives according to (2) 60-80% error in the differential based on these measurement systems. Practice has shown that really efficient in systems for measuring fuel consumption gauges of two or three types – the rotating plate (piston), swash plate and gear – in general or on the oval gears. Flowmeters, designed to measurement of small (up to 200 – 500 l / h) flow rate in long mode, are made only in versions with a rotating plate and the oval gears. We compare these two types of flow meters in terms of hydrodynamic resistance, which they create in the engine fuel system. Flowmeters with rotating washer creates resistance to the flow of diesel fuel (depending on its size) within the 10-100 mbar. Values for flowmeters oval gears a bit higher – from 10 to 450 mbar. This means that the flow on a rotating puck to the minimum height for diesel fuel receipts "gravity" is about 10 cm, and for flow in the oval gears 40-50cm. Is it much? For comparison – the standard pressure due to the fuel pump swap (TNND) is 2,5-7,0 bar, it is necessary, including compensation for the hydraulic resistance created fine filter fuel as it is pollution (up to 1,5 bar). Thus, the pressure generated by pump toplivopodkachki more than enough for inclusion in one or two meters (with differential system for measuring fuel consumption). The higher value of the hydrodynamic resistance to flow of oval gears due, including the manufacture of highly accurate measuring elements (gear and cameras), excluding the so-called the effect of "leakage", which is characteristic for the flow on a rotating puck when the flow at small washer remains stationary (not counting in progress), and the fuel passes through the meter unreported. Flowmeters on oval gears fix any minimum flow rate at a slightly higher ratio relative tochnosti.Eto is their undoubted advantage.