Ultrasonic instruments

Ultrasonic insturments use ultrasonic sounds to generate desired results.

Ultrasonic sounds are the sounds that human ear cannot hear. Our ears cannot read these sound waves.

Ultrasonic thermometers are based on the effect of the temperature on the velocity of sound waves in hte medium transmitting hte sound waves. Temperature dependence of velocity in an ideal gas.

Ultrasonic thermometers can be used at temprature extremes, in high electric fields, or when the medium being measured is inaccessible. It is also useful for averaging the temperature of bulk materials or for profiling furnace temperatures.

Advantages

• Acoustical temperature sensors can measure temperature from the cryogenic range to plasma level (20,000 degree)
• This sensor has high accuracy.

Disadvantages

• Ultrasonic thermometer has high cost.
• Ultrasonic thermometer have non-ideal gas behavior.
• These require pressure corrections.