Eine Metallfilmsonde zur Messung von kleinen und schnellen Strömungstemperaturschwankungen

Measurements of the temperature fluctuations in flows are restricted to low fluctuation frequencies, if the temperature probes which have been available and which have a relative high thermal inertia are used. A newly constructed metalfilm probe, which works in principle as a resistance thermometer, overcomes this restriction to a large degree so that temperature fluctuations in the order of 0.01 °C can be measured up to fluctuation frequencies of about 5 kHz. The construction, the procedure of manufacture, and a method of calibration are presented for the newly developed probe, and its applicability for the measurement of temperature fluctuations in flows is demonstrated by some examples (measurements of the natural temperature fluctuations in the wake of a circular rod in air flow at a Reynolds number of about 5 · 10⁴). Some further applications of the probe are mentioned, in which its high sensitivity and its low thermal inertia is especially advantageous (measurement of flow velocities and measurement of fast temperature variations by infra-red detectors).