Air velocity measurement

The problem

Air velocity measurement at the certain point within dense construction of electronic cards was always unresolved problem.

There are two main reasons for that:


The first device that got close to the solution was the sensor of Accusense. In plastic plate measuring 5x20mm they place thermocouple and hot-wire within the holes 3mm diameter The main disadvantages of this sensor are:

  • It must be mounted exactly normal to the flow.
  • 5x20mm block within tiny channels of electronic equipment is not negligible. Advanced Thermal Solutions from Boston (USA) want further and succeeded to encapsulate hot-wire and thermistor in single ball 1mm diameter.


    In order to assure best service quality we in Agren use the most professional equipment. Therefore, ATS system was purchased. It allows, among other:

    • Measure Air Velocity and temperature at 8 points at the same time.
    • Screening of Air velocity within a channel in order to calculate flow rate.
    • Discovery and estimation of air leakages.
    • Evaluation of Heat Sink performance in their "natural" environment


    • Velocity readings are not continuous, there are defined periods of time when the same sensor measures temperature.
    • The size of sensor is constant, in order to change its height additional parts are needed.
    • The sensors are very gentle and become dysfunctional very easy. There is no possibility to repair broken sensor, and the new one should be purchased. The price of the sensors is relatively high.