Unsteady probes

5-hole-probe unsteady

Unsteady probes combine the robustness of a pressure probe (e.g. 5-hole probe) with high temporal resolution pressure sensors. Frequencies of up to several kHz are measurable, depending on the probe geometry.


All pressure probes have a certain frequency response. Due to their internal diameters and volumes. It is characterized by amplitude gain/attenuation and phase shifts. Vectoflow can offer various solutions if you want to measure flow characteristics with a frequency higher than a couple Hz. Many of our custom material and geometry combinations are possible.

  • If a fast frequency response >200 Hz is needed we offer fast response probes. They can be calibrated up to a couple of kHz. They have integrated sensors and optimized internal diameters.
  • We experimentally determine the transfer function of conventional probes and systems (including pressure lines and sensors) up to 200 Hz or more.
  • Our own system design software can evaluate a design prior to its use. This is especially useful if you need the influence of tubing and sensor volume.


Number of measurement heads tbd by customer
Number of holes in measurement head. 1, 3, 5, 7 oder tbd by customer
Size 280 mm, other length possible
Tip diameter min. > 3 mm
Geometry measurement head Kiel, conical, spherical
Material stainless steel, titanium, inconel, high-temperature stainless steel
Fixture tbd by customer
Connections tbd by customer
Reference tbd by customer
Temperature range up to 450 °C
Angle measurement range ± 70° (dependent on number of pressure holes)
Angle measurement accuracy < ± 1°
Velocity measurement range 3 m/s up to Mach 2
Velocity measurement accuracy < ± 1 m/s
Resolvable frequency max. in the area of a few kHz depending on probe geometry