Accession Number:

ADA052261

Title:

On the Feasibility of using Thermistors to Measure Ocean Current Velocities,

Descriptive Note:

Corporate Author:

STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB

Personal Author(s):

Report Date:

1962-01-01

Pagination or Media Count:

22.0

Abstract:

The characteristic of thermistors which makes them useful for measuring fluid velocities is their large negative temperature coefficient of resistance, which can be as high as -5.8 percentdegree centigrade at room temperature, compared to 0.30 percentdegree centigrade for platinum. A thermistor immersed in a stationary fluid can be heated by means of a current to a temperature higher than its surroundings. Thus it will lose heat by steady-state convection. When a thermistor is exposed to a moving stream of fluid, it loses further heat by forced convection. The temperature of the thermistor and hence its resistance depends on the fluid velocity and temperature as well as the heating current. Assuming a constant ambient fluid temperature, a relationship exists between the fluid velocity and the voltage across the thermistor.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE