Browse Prior Art Database

Velocity Measurement Using Thermal Pulses

IP.com Disclosure Number: IPCOM000085353D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Calise, JA: AUTHOR [+2]

Abstract

This apparatus is utilized for measuring the velocity of a fluid flowing through a channel. A fluid channel 2 has fluid such as water flowing in the direction of arrow 4. A variable-frequency square-wave generator 6 provides a square-wave train to a power booster or amplifier 8, which provides the amplified square-wave as a reference signal to an oscilloscope 10, and to a heating element 12 which is immersed in the fluid channel 2.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 65% of the total text.

Page 1 of 2

Velocity Measurement Using Thermal Pulses

This apparatus is utilized for measuring the velocity of a fluid flowing through a channel. A fluid channel 2 has fluid such as water flowing in the direction of arrow 4. A variable-frequency square-wave generator 6 provides a square-wave train to a power booster or amplifier 8, which provides the amplified square-wave as a reference signal to an oscilloscope 10, and to a heating element 12 which is immersed in the fluid channel 2.

The fluid in the channel 2 is heated by the element 12, and a hot film probe 14 senses the temperature change in the fluid and provides a temperature signal which is proportional to the sensed temperature change, to a constant- temperature anemometer 16.

The anemometer 16 provides a square-wave output to a digital comparator device 18 which provides a 0 output signal when the sensed temperature is below a reference temperature, and provides a 1 output signal when the sensed temperature is equal to or greater than the reference temperature. The output from the comparator device 18 is provided to the oscilloscope 10.

With reference to Fig. 2A, the frequency wave form from amplifier 8 at A is illustrated by the wave shape 20, and the signal output from the anemometer 16 at B is illustrated by the wave shape 22. In Fig. 2B the wave shape 22 is once again illustrated with a wave shape 24 being included, which is the output signal C from the comparator 18. Fig. 2C illustrates the signal output 20 fro...