Oscillator detector

Patent · Tue May 13 04:00:00 EDT 1980

OSTI ID:5769929

Potter, B M

An alien liquid detector employs a monitoring element and an oscillatory electronic circuit for maintaining the temperature of the monitoring element substantially above ambient temperature. The output wave form, eg., frequency of oscillation or wave shape, of the oscillatory circuit depends upon the temperaturedependent electrical characteristic of the monitoring element. A predetermined change in the output waveform allows water to be discriminated from another liquid, eg., oil. Features of the invention employing two thermistors in two oscillatory circuits include positioning one thermistor for contact with water and the other thermistor above the oil-water interface to detect a layer of oil if present. Unique oscillatory circuit arrangements are shown that achieve effective thermistor action with an economy of parts and energizing power. These include an operational amplifier employed in an astable multivibrator circuit, a discrete transistor-powered tank circuit, and use of an integrated circuit chip.

• Assignee: IFI; EDB-82-037361
• Patent Number(s): US 4202203
• OSTI ID: 5769929
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020900* -- Petroleum-- Environmental Aspects
520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
DESIGN
DETECTION
EFFICIENCY
ELECTRONIC CIRCUITS
ENERGY EFFICIENCY
FREQUENCY MEASUREMENT
MEASURING INSTRUMENTS
MONITORS
OIL SPILLS
OSCILLATIONS
SEMICONDUCTOR DEVICES
TEMPERATURE DEPENDENCE
THERMISTORS
WATER POLLUTION MONITORS