Accession Number:

AD0440879

Title:

A THERMISTOR PROBE FOR MEASURING PARTICLE ORBITAL SPEED IN WATER WAVES,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE HYDRODYNAMICS LAB

Personal Author(s):

• Eagleson, P. S.
• van de Watering, W. P. M.

Report Date:

1964-03-01

Pagination or Media Count:

50.0

Abstract:

The development of a thermistor probe and the necessary additional electronic circuitry to measure the temporal and spatial distribution of the magnitude of the orbital velocity vector in water waves is described. The proposed use of this probe gives rise to a number of requirements. These considerations are presented. The thermis tor is assembled into a structural support in such a way as to provide minimum directional sensitivity and adequate insulation from the water. A constant temperature bridge-amplifier circuit is designed with optimized values of resistances and capacitance to match such properties of the thermistor as frequency response and sensitivity. A steady-state calibration is performed. It is proven that this static calibration can be used to measure velocities in an unsteady motion up to at least a frequency of 0.5 cps. The behavior of the instrument is checked in laboratory water waves. Author

Descriptors:

• *ELECTROMAGNETIC PROBES
• *VELOCITY
• THERMISTORS
• FLUID FLOW
• WATER
• CALIBRATION
• WATER WAVES
• ELECTRIC BRIDGES
• SUSPENSION DEVICES
• CIRCUITS
• CURRENT AMPLIFIERS
• EQUATIONS
• INTEGRATORS

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE