Tubing sensors

The maximum allowable dispersion will include contributions from all the different dispersion sources. Furthermore, the analyst may frequently be required to place a large volume of sample on the column to accommodate the specific nature of the sample. The peak spreading resulting from the use of the maximum possible sample volume is likely to reach the permissible dispersion limit. It follows that the dispersion that takes place in the connecting tubes, sensor volume and other parts of the detector must be reduced to the absolute minimum and, if possible, kept to less than 10% of that permissible (i.c.,1 % of the column variance) to allow large sample volumes to be used when necessary. 

Fig. 8.11 Two versions of a SnC>2 sensor with incorporated heating element (a) a ceramic tube sensor and (b) planar sensor (adapted from Heiland, 1982)...

Kobayashi, T., Yano, T., Mori, H., and Shimizu, S. (1979) Cultivation of microorganisms with a DO-stat and a silicone tubing sensor. Biotechnol. Bioeng. Symp. 73-83. 

See next page for an overview diagram of the electrical system. There are two sensors in the system, the pressure switch with a bourdon tube sensor on the storage tank, and a fill level switch which controls the fluid level of the electrolyte. The fill level switch can be designed for a number of sensor options, including infrared and visible light photonic, with or without fiber optics capacitive inductive ultrasonic and others. 

In an electrical resistance (ER) probe, a strip, wire or tube sensor of known cross section is exposed to the environment. In the case of concrete structures, it must be embedded at the time of construction otherwise it is not in the same environment as the reinforcement it is supposed to simulate. The sensor... 

Such sensors can be provided as tube sensors or as flat tape sensors. Tape sensors allow its integration into composites or into the interface zone of multi-layer materials. Several sensors can be interrogated by multiplexing. 

Sensors on the tree allow the control module to transmit data such as tubing head pressure, tubing head temperature, annulus pressure and production choke setting. Data from the downhole gauge is also received by the control module. With current subsea systems more and more data is being recorded and transmitted to the host facility. This allows operations staff to continuously monitor the performance of the subsea system. 

Progress in mean of modelisation and inverse problem solving [1] let us hope to dispose soon of these tools for flaws 3D imaging in Non Destructive Control with eddy current sensors. This will achieve a real improvement of the actual methods, mainly based upon signature analysis. But the actual eddy current probes used for steam generators tubes inspection in nuclear industry do not produce the adequate measurements and/or are not modelisable. 

The starting point of imaging is the modelisation of the physical process implied when using the sensor once known the exci-tator geometry and the conductivity in any point of the tube, one must be able to compute the magnetic field at any point in the measurement area ... 

Before starting the realisation of silicium coils, we construct a simpler probe with a 27 mm long excitation coil and 16 wired coil sensors, with 1 mm diameter and 1 mm long. We cannot hope any reconstruction with such a probe, but this allows to validate the whole approach. We tried it with test tubes with longitudinal or circonferential notches, external or internal, 100 pm wide, 100%, 60%, 40%, 20% and 10% deep. Our attention has been especially focused on circonferential notches, which are difficult to detect with usual probes. For example, the measurement signals at 240 kHz standard frequency are shown figure 6 7. 

The comparison between the detection cartography (fig. 12) and the signal cartography given by the sensors (figure 7) for the same tube sample, shows the efficiency of our detection technique. Indeed, in the detection cartography, every inner notch present in the tube sample, even the 10% deep notch, is detected... 

D. Miller, D.Placko "Pre-processing of signals delivered by a new eddy current sensor for non ferromagnetic tubes testing" in IMTC 96... 

Figure 2. Triangulation Sensor Rotates as it is Drawn Through a Tube...

Video links Video recording Video sensor Video tape Video tapes Vidicon Vidicons Vidicon tubes Vifilcon-A... 

Flow. The principal types of flow rate sensors are differential pressure, electromagnetic, vortex, and turbine. Of these, the first is the most popular. Orifice plates and Venturi-type flow tubes are the most popular differential pressure flow rate sensors. In these, the pressure differential measured across the sensor is proportional to the square of the volumetric flow rate. 

The proper installation of both orifice plates and Venturi-type flow tubes requires a length of straight pipe upstream and downstream of the sensor, ie, a meter mn. The pressure taps and connections for the differential pressure transmitter should be located so as to prevent the accumulation of vapor when measuring a Hquid and the accumulation of Hquid when measuring a vapor. For example, for a Hquid flow measurement in a horizontal pipe, the taps are located in the horizontal plane so that the differential pressure transmitter is either close-coupled or connected through downward sloping connections to allow any trapped vapor to escape. For a vapor measurement in a horizontal pipe, the taps should be located on the top of the pipe and have upward sloping connections to allow trapped Hquid to drain. 

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