Back to results
US 4,349,881 AGranted
Vibration instruments
AssigneeInternational Telephone and Telegraph Corporation
InventorsMilton H. November, LaVern D. Lyon, Joseph J. Ponzi
Life of this patent
Estimating the term…
Abstract
A quartz tuning fork is provided which may be employed in several instruments for measuring the properties of fluids. The tuning fork may be employed, for example, in a gravitometer, a barometer, an altimeter or a temperature sensor.
Claims17
A vibration instrument comprising:
- a base;
- a housing sealed to said base to define a first space;
- vibratable tuning fork means in said first space including two substantially parallel legs connected at one pair of mutually adjacent ends by a bight portion, said tuning fork means having a variable frequency of vibration f;
- a longitudinal magnetostrictive member having first and second opposite ends on an axis fixed relative to said base and said bight portion, respectively, said parallel legs extending in a direction from said bight portion away from the said second end of said member in positions approximately symmetrical about said axis;
- a piezoelectric crystal fixed relative to said bight portion to produce an output signal of said frequency f equal to the said vibrational frequency of said tuning fork means;
- first driver means including a first driver coil mounted around said member, said first driver means also including an amplifier connected from said crystal to impress a signal upon said first driver coil of the same said frequency f to cause said tuning fork means to vibrate at said frequency f, said first driver means having an output at which an output signal is produced, said output signal having said frequency f;
- and first computer means connected to receive said crystal output signal for producing an output signal directly proportional to the first expression:
- ##EQU16## where f.sub.g =f, and A.sub.g and B.sub.g are constants, said constants A.sub.g and B.sub.g having first and second sources, respectively, to provide first and second signals, respectively, to said first computer means directly proportional to said constants A.sub.g and B.sub.g, respectively, and where the said first expression is directly proportional to the density of a fluid in which said vibratable tuning form means is immersed.
5 more elements
A gravitometer comprising:
- first means for providing a first enclosed space to hold air of a temperature T.sub.a ;
- second means for providing a second enclosed space to hold a gas of interest of a temperature T.sub.g ;
- first vibrator means in said first enclosed space having a member to vibrate at its resonant frequency f.sub.a ;
- second vibrator means in said second enclosed space having a member to vibrate at its resonant frequency f.sub.g ;
- means to cause the pressures in said first and second enclosed spaces to be equal;
- first and second sensors in said first and second enclosed spaces to produce output signals directly proportional to T.sub.a and T.sub.g, respectively;
- first and second pick-offs connected from said first and second vibrator means to produce output signals of frequencies f.sub.a and f.sub.g, respectively;
- computer means responsive to said first and second sensor output signals and both of said pick-off output signals for producing an output signal proportional to the gravity G of the gas in said second enclosed space.
5 more elements
A barometer comprising:
- chamber means for providing a partially enclosed space to hold air at a temperature of T.sub.p ;
- a first sensor for producing an output signal directly proportional to T.sub.p ;
- said chamber means having an opening therethrough to admit air from the atmosphere thereinto;
- vibrator means in said enclosed space having a member to vibrate at its resonant frequency f.sub.p ;
- a pick-off for producing an output signal of frequency f.sub.p ;
- and computer means connected to receive said first sensor output signal and said pick-off output signal for producing an output signal proportional to atmospheric pressure P.sub.p.
3 more elements
An altimeter comprising:
- chamber means for providing a partially enclosed space to hold air at a temperature of T.sub.p ;
- a first sensor for producing an output signal directly proportional to T.sub.p, said chamber means having an opening therethrough to admit air from the atmosphere thereinto;
- vibrator means in said enclosed space having a member to vibrate at its resonant frequency f.sub.p ;
- a pick-off for producing an output signal of a frequency equal to f.sub.p ;
- and computer means responsive to said first sensor and pick-off output signals for producing an output signal proportional to altitude y.
2 more elements
Temperature sensitive apparatus comprising:
- enclosure means providing a sealed vacuum chamber;
- vibrator means in said vacuum chamber having a member to vibrate at its resonant frequency f;
- a pick-off for producing an output signal of said frequency f;
- means to provide a heat conductive path mounted through said enclosure means extending to a position in contact with said member;
- and computer means connected to receive said pick-off for producing an output signal directly proportional to the temperature T.sub.x of said member.
2 more elements
Dependencies are inferred from the claim text.