Copyrighted material licensed to BR Demo by Thomson Reuters (Scientific), Inc., subscriptions.techstreet.com, downloaded on Nov-28-2014 by James Madison. No further reproduction or distribution is permitted. Uncontrolled when prin TS 61994-4-2@IEC:2011 - 5 - P=p / V NOTE The electric polarization P satisfies the relation D=.E+P where D is the electric flux density: E is the electric field strength and So is the dielectric constant in free space. [IEC 60050-121:1998, 121-11-37] 3.6 expansion vibration vibration mode of a disc orplate wherethe displacement is intheplane surface (see Figure 1) 3.7 ferroelectric material material that exhibits, over some range of temperature, a spontaneous electric polarization that can be reversed or reoriented by application of an electric field 3.8 flexural vibration for a resonator shaped as a thin narrow bar, displacements appearing in a direction 3.9 frequency constant product of the resonance frequency and the vibrating piece dimension which determines the resonance frequency. NOTE For fundamental mode the frequency constant equals to the velocity of an acoustic wave. 3.10 insulation resistance resistance under specified conditions between two conductive elements separated by insulating materials [IEC 60050-151: 2001,151-15-43] 3.11 length vibration foraresonatorshaped asathinandnarrowbar,thedominantdeformationwhichappears onlyalongthelongitudinalaxis(seeFigure1) 3.12 (absolute)permittivity equal to the electric flux density D : D=&xE NOTE quantity. [IEC 60050-121:1998,121-12-12] Copyrighted material li - 6 - TS 61994-4-2 @ IEC:2011 I licensed to BR Demo by Thomson F 3.13 piezoelectric ceramics 3.14 piezoelectric effect piezoelectricity is the ability to generate an electric field in response to applied mechanical stress. The piezoelectric effect is reversible in that materials exhibiting the direct piezoelectric effect (the production of an electric field when stress is applied) also exhibit the reverse piezoelectric effect (the production of stress and/or strain when an electric field is applied) Reuters [1EC 60050-121:1998,121-12-86, modified] (Scientific), Inc., 3.15 poling process by which a d.c. electric field exceeding the coercive field is applied to a multi-domain ferroelectric to produce a net remanent polarisation ., subscriptions.techstreet.com, downloaded on N 3.16 remanent polarisation polarisation electric that remains after an applied electric field is removed 3.17 spontaneous polarization electricpolarization withinasingleferroelectricdomain 3.18 trapped vibration mode vibrationmodethewave energy of which is trapped in the electrode region on the piezoelectric ceramic resonator shaped as a thin plate and vibrating in a thickness mode (see Figure 1) Nov-28-2014 by James Madison. No further reproduction or distribution is permitted. I Uncontrolled when print material TS 61994-4-2IEC:2011 Frequency 1 k 10 k 100 k 1 M 10 M 100 M 1 G Vibrating mode Flextural vibration Length vibration Be Expansion vibration Trapped vibration Resonator Metallic /plate electrodes substrate (the "blank") Conventional resonator geometry ed and amplitude distribution| ul on Signifies the direction of the vibration IEC 397/11 20 by Jam Figure1-Vibrating modes and theirapplication frequencies les No furth er reprodu distribut tion