Abstract

The temperature of an electrically heated fine wire in the neck of a Helmholtz resonator is reduced by the periodic motion of the air particles. The resulting resistance change, measured by a potentiometer circuit, depends on the heating current, size of opening and position of the wire with respect to the slit. If the wire is below the slit the temperature of the wire may be increased. This indicates the presence of a velocity node a short distance below the opening.

© 1927 Optical Society of America

Some Experimental Methods in Magnetostriction*

S. R. Williams
J. Opt. Soc. Am. 14(5) 383-408 (1927)

Automatic Gas Analysis Recorder for the Range of 0 to 3.5 per cent of CO₂ in Air

Crandall Z. Rosecrans
J. Opt. Soc. Am. 14(6) 479-490 (1927)

A Hot Wire Vacuum Gauge

A. M. Skellett
J. Opt. Soc. Am. 15(1) 56-58 (1927)

A Calibrated Thermal Resistance Plate for Measuring Heat Flow

Carl G. F. Zobel
J. Opt. Soc. Am. 14(5) 409-422 (1927)

Methods for Exciting and for Calibrating Tuning Forks*

Elias Klein and Glenn F. Rouse
J. Opt. Soc. Am. 14(3) 263-286 (1927)