English explanation
Crystal Element A piece of quartz crystal cut as specified in terms of shape, dimensions and cutting angles.
Electrodes A conductive thin film vacuum-evaporated onto both sides of a crystal wafer to allow AC voltage to be
Enclosure A case housing a crystal wafer, electrode and support system, which prevents outside conditions from
having any mechanical or environmental effect on its contents. The case also has terminals permitting
the electrical connection of the electrode to an outside circuit.
Crystal Unit A mounted crystal wafer provided with electrodes and housed in a holder.
Overtone Order Overtone order : A number assigned from sequentially increasing integers for successively occurring
overtone frequencies with a fundamental wave oscillation of 1 in a specified oscillation mode. An
overtone frequency in a slide or extension mode can approximate the value obtained by multiplying
the fundamental wave frequency by an integer.
Resonance Frequency Series resonance frequency : Lower frequency of the two given when the electrical impedance of a
crystal unit becomes resistant near its resonance point.
Load Capacitance Effective series capacitance measured from the terminals of a crystal unit to the oscillation circuit and
determined as a condition when using a crystal unit in an oscillation circuit. The operating frequency is
determined by the electrical characteristics of a crystal unit and the load capacitance.
Nominal Frequency Nominal value expressed in terms of frequency.
Series resonance state Condition of resonance in the case of limitless load capacitance
Frequency Tolerance Deviation from the nominal frequency expressed as a ratio to nominal frequency.
Equivalent Series Resistance Equivalent resistance for series resonance frequency. Simply called equivalent resistance when no risk
of confusion is possible.
Load Resonance Resistance Resistance for the lower frequency of the two given when the electrical impedance becomes resistant
near the resonance point of a circuit, with the load capacitance connected to a crystal unit in series.
Operating Temperature Range Temperature range within which crystal units operate under specified conditions.
Level of Drive Electric-power or current level under the specified conditions of a crystal unit.
Main Mode / Unwanted Response When there are some resonance frequencies near the nominal frequency, main mode indicates the
most prominent resonance frequency and unwanted response indicates other resonance frequencies