Vibration densitometer apparatus

Claim 1

A temperature compensated densitometer comprising: a probe including support means and vibratable structure mounted thereon; first means mounted on said support means to vibrate said structure, said first means having an input lead and being actuable in response to receipt of an input signal on said first means input lead; second means having an output lead, said second means being adapted to sense vibration of said structure and to produce an A.C. output signal on said output lead thereof in synchronism with vibration of said structure; a bonding agent substantially fixing said second means to said structure to transmit the vibration of said structure to said second means; an output junction; third means including a preamplifier having input and output leads, said preamplifier input lead being connected from said second means output lead; fourth means connecting the output lead of said preamplifier to said output junction; fifth means connecting said output junction to said first means input lead, said structure and said first, second, third, fourth and fifth means forming a closed loop electromechanical oscillator having a gain adequate to sustain oscillation of said structure; and utilization means connected from the output of said third means, said bonding agent being adapted to soften as its temperature increases and to damp vibration of said second means, said second means producing an A.C. output voltage the amplitude of which increases with increasing temperature.