摘要 |
<p>QUARTZ CRYSTAL RESONATOR A method and apparatus utilizing a quartz crystal resonator with an orientation substantially equal to (yxwl) 21.93.degree./33.93.degree. vibrating simultaneously in two thickness modes to accurately measure temperature and unknown frequencies or to provide a stable frequency signal source. By combining a quartz crystal resonator of the above type with either digital or analog compensation, the frequency-temperature deviation of one of the crystal mode frequencies is used as an internal thermometer and the second crystal mode frequency as a reference frequency signal. The frequency signal for the thermometer function is utilized by the compensation network to correct the measurements made with, or to stabilize, the frequency of the reference frequency signal. Additionally, the analog or digital compensation is accomplished by means of either a curve-fitting routine or an interpolation look-up table routine.</p> |