| Autor: |
Herman, Bruce, Stewart, Harold F. |
| Zdroj: |
Journal of the Acoustical Society of America; 1973, Vol. 53 Issue 1, p341-341, 1p |
| Abstrakt: |
This paper describes a constant temperature environment calorimeter for the absolute measurement of ultrasonic power. This design uses a variation of the classical calorimetric procedure of power measurement as applied specifically to ultrasonic transducers. This measurement technique has advantages over other methods in that it is the least affected by beam shape and pulse duration. The calorimeter consists of a conical shaped calorimeter cup mounted in an outer brass cylindrical container. The calorimeter is placed in a water bath, which provides both a constant temperature environment and an effective medium for the propagation of ultrasound. The calorimeter cup is filled with Dow Corning 710 silicon fluid, which is an effective absorption medium. It has a 112-in. entrance window of gold coated nylon separating the silicon fluid from the water bath. The gold film is used as a resistance heater to maintain quasi-adiabatic conditions between the silicon absorbing fluid and the water environment at the entrance membrane. The temperature difference between the silicon absorbing fluid and the outer brass cylinder is measured with a bank of chromel-constantan thermocouples. This measured temperature difference is a measure of the ultrasonic power. Calibration of the system is accomplished with a constant resistance heating coil immersed in the Dow Corning 710 absorbing fluid. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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