Miniature wire probes have 5 µm diameter, 1.25 mm long platinum-plated tungsten wire sensors. The wires are welded directly to the prongs and the entire wire length acts as a sensor.
The sensors are arranged in X-arrays, where they form an angle of 90° with one another. The probe body is a 2.3 mm diameter ceramic tube, equipped with gold-plated connector pins that connect to the probe supports by means of plug-and-socket arrangements. Dual-sensor probes have marks (one and two dots) that indicate the sensor number.
The Dual-sensor probes are designed for use in two-dimensional flows of low turbulence intensity. The accuracy of turbulence measurements may be reduced because of interference from the prongs. On the other hand, the more rigid construction makes them more suitable for high speed applications without the risk of self-oscillation. The probes are the cheapest in the Dantec Dynamics program and are straightforward to repair. All X-probes measure two velocity components simultaneously in turbulent, instationary two-dimensional flow fields. They provide information for calculation of Reynolds shear stress. The flow vector may not exceed ±45°.
Dual-sensor miniature wire probes are available in four configurations. The picture on the right shows the dimensions common for the probes.
Mounting: 6 mm dia. probe support.
Miniature X wire probe, straight (55P61)
X-probe with straight prongs and with the sensor plane parallel to probe axis.
This probe is used in free-stream applications. Mounts with the probe axis parallel to the direction of main flow, so that the predominant flow vector attacks the two wires under 45°.
Miniature X wire probe, right angle, parallel (55P63)
X-probe with right-angled prongs and with the sensor plan parallel to probe axis.
Intended for radial operation in pipes or ducts. This probe measure the U-V components. Mounts with the probe axis perpendicular to the main flow and rotated, so that the predominant flow vector attacks the two wires under 45°.
Miniature X wire probe, right angle, perpendicular (55P64)
X-probe with right-angled prongs and with the sensor plan perpendicular to probe axis.
Intended for radial operation in pipes or ducts. This probe measure the U-W components. Mounts with the probe axis perpendicular to the main flow and rotated, so that the predominant flow vector attacks the two wires under 45°.
|Technical Data For miniature wire Sensors|
|Sensor material||Platinum-plated tungsten|
|Sensor dimensions||5 µm dia, 1.25 mm long|
|Sensor resistance R20 (approx.)||3.5 Ω|
|Temperature coefficient of resistance (TCR) α 20 (approx.)||0.36%/°C|
|Max. sensor temperature||300°C|
|Max. ambient temperature||150°C|
|Max. ambient pressure||Depends on the type of mounting|
|Min. velocity||0.05 m/s *|
|Max. velocity||500 m/s|
|Frequency limit fcpo (CCA mode, 0 m/s)||
|Frequency limit fmax (CTA mode)||
* Influence from natural convection up to approx. 0.20 m/s.