Fast Response Measurement Systems

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


The unsteady probes from Vectoflow make it possible to detect high-frequency flow phenomena in the kHz range and not just in terms of only one measured quantity, but related to all quantities, that are also available from a conventional multi-hole probe: velocities, flow angles, total and static pressure, Mach number and density. In order to achieve this high temporal resolution, the pressure sensors must be as close as possible to the probe head. This is to minimize the modulation of the pressure fluctuations in amplitude and phase. Furthermore, this modulation must be determined experimentally, which is being done at Vectoflow with a specially developed frequency calibration rig. Of course, all the advantages of the the Vectoflow steady probes are also available to the customers for the unsteady probes, due to the proprietary additive manufacturing process, like the geometric flexibility and increased robustness of the probes.

  • Complete measurement system for unsteady flow phenomena
  • Probes with embedded pressure sensors (higher frequency response) or conventional probes with seperated pressure sensors
  • Frequency calibration of each pressure channel
  • Hardware for data acquisition
  • Software for data post-processing

Interested? Contact us now!


Geometry Straight, L-shaped, Cobra or Drilled Elbow
Number of pressure holes Custom (5-Standard)
Max. length Custom
Min. tip diameter Standard 3-4 mm (down to 1 with Micro-Printing techniques)
Shaft Diameter 15 mm (standard)
Tip geometry Conical, spherical or custom
Material stainless steel, titanium, inconel, plastics
Fixture Square, hexagonal, one-sided flattened cylinder or custom
Reference reference surface normal to z-axis
Pressure sensors Custom (>1PSIG)
Acquisition Hardware 2x NI 9237; 1x cDAQ 9181 (Chassis); or custom
Acquisition & Postprocessing Software Included (Labview based)
Temperature range up to 100 °C (higher with water cooling)
Angle range ± 60° (depending on number of holes)
Angle accuracy < ± 1°
Velocity range 3 m/s up to Mach 1
Velocity accuracy < ± 1 m/s

Download the datasheet for unsteady measurement systems

Frequency Calibration

Calibration System Acoustic Calibration
Frequency Range <25 kHz (depends on Probe geometry)
Transfer function frequency step size Custom