Kiel probe

Dynamic pressure may be measured by use of a pitot tube that is a simple impact tube. These tubes measure the pressure at a point where the velocity of the fluid is brought to zero. Pitot tubes must be parallel to the flow. The pitot tube is sensitive to yaw or angle attack. In general angles of attack over 10° should be avoided. In cases where the flow direction is unknown, it is recommended to use a Kiel probe. Figure 10-3 shows a Kiel probe. This probe will read accurately to an angle of about 22° with the flow. 

FIG. 10-3 Kiel probe. Accurate measurements can be made at angles up to 22.5° with the flow stream. 

Fig. III.2. Electromagnet used for the rotational Zeeman effect measurements at Kiel. The upper yoke may be lifted by hydraulic jacks in order to insert spacers on top of the side yokes for different gap widths. Bearings in the side yokes are to allow for lateral access of the gauss-meter probe tip. The power connections (/mu = Amps, each coil) arc visible at the right front side. The overall length of the gap is 250 cm and the maximum field at a gap width of 6 cm is close to 21 kG, and at a gap of 0.6 cm the field is 31 kG...

The three volutes were installed downstream of the same stage (impeller and dilfuser) as shown in Fig. (5). The impeller is a medium flow (q) = 0.0956)/medhim Mach ( Mu = 0.9) 3D impeller equipped with a free vortex diffuser with a diffusion ratio of 1.45. Total and static pressures were measured during the test by means of wall static pressure taps and total pressure ( Kiel type) probes inside the flow as shown in Fig. (6). 

Jung, W. (1992). Probing acceptance A technique for investigating learning difficulties. In R. Duit, F. Goldberg H. Niedderer (Eds.) Research in Physics Learning - Theoretical Issues and Empirical Studies. Kiel IPN, 278-2295. 

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