Abstract: Provided is a PLL apparatus outputting a frequency signal from a voltage-controlled oscillation unit in synchronization with an external reference frequency signal, in which the fluctuation of the frequency is reduced even when the external reference signal has a trouble For solving the problem, as a result of monitoring the signal level of the external reference frequency signal, when its signal level falls within a set range, data regarding a phase difference created by a phase difference data creating means is used for the PLL control, but when the signal level does not fall within the set range, it is recognized that the supply of the signal has been stopped or the supplied signal has abnormality and the data regarding the phase difference stored in a storage unit, for example, the stored latest data or the pre-created data is used instead for the PLL control.

Abstract: An object of the present invention is to provide a sensing device capable of easily and collectively displaying, based on pieces of time-series data of frequencies of piezoelectric resonators obtained for each concentration of a substance to be absorbed in solutions, pieces of variation data of the frequencies for each concentration caused by an absorption of the substance to be absorbed, in a state of aligning absorption start points. A main structure of the present invention is composed of a unit for setting an absorption start point of a substance to be absorbed in pieces of time-series data, and an editor for performing processing to combine and display at least frequency variation regions in the pieces of time-series data in a state of aligning the absorption start points of the substance to be absorbed.

Abstract: To provide a Colpitts oscillation circuit formed with a quartz resonator and a transistor amplifier circuit, which can secure sufficient negative resistance, obtain stable oscillation, negate the need for an amplitude control circuit, and realize stabilization against temperature variations. In order to solve the problem, a structure in which the impedance of a tuning circuit provided in a collector of the transistor exhibits inductivity at the oscillation frequency is provided. The impedance ratio at the oscillation frequency of a capacitor C2 connected between a base and an emitter to a capacitor C3 connected between the emitter and a ground, of the transistor is set at 3 to 1 or more. Furthermore, the impedance of capacity C2 connected between the base and the emitter at the oscillation frequency is set at 300 ? or more. A bias resistance R1 connected between the collector and the base of the transistor is set at 3 k? or less.

Abstract: Provided is a Angevin type quartz sensor which is high in measurement sensitivity, suppresses the influence of the surface tension of a sample solution during measurement, and enables an installed quartz resonator to stable oscillate. An opposing surface portion opposes one surface side of the quartz resonator via a housing area and a pouring opening formed in the outside area of the opposing surface portion. Measurement is conducted in a standstill state where the sample solution is filled in the lower side of the opposing surface portion. Since stress due to the surface tension of the sample solution does not act in this state, the quartz resonator can oscillate with reliability. Therefore, the quartz sensor can reduced the thickness of the quartz resonator, which realizes highly sensitive and highly accurate measurement.

Abstract: An object of the present invention is to provide a sensing device capable of easily grasping whether or not a concentration of a sensing target is equal to or less than a standard value.

Abstract: A sensing instrument includes: a reference sensor including a reference piezoelectric resonator not adsorbing a substance to be sensed; a reference oscillator circuit oscillating the reference piezoelectric resonator; a measuring unit receiving an oscillation output of a sensing oscillator circuit and an oscillation output of the reference oscillator circuit in a time-series manner to measure frequencies of the oscillation outputs of the oscillator circuits; and a data creator creating time-series data of a difference between a frequency in a sensing sensor and a frequency in the reference sensor, based on the frequencies of the oscillation outputs of the oscillator circuits obtained by the measuring unit. Therefore, a frequency changed due to a factor other than the adsorption of the substance to be sensed is cancelled.

Abstract: In a sensing instrument using a quartz sensor on whose front surface an adsorption layer for adsorbing a substance to be sensed is formed and which changes in natural frequency by the adsorption of the substance to be sensed, the present invention has an object to quickly detect a trouble of the quartz sensor to prevent an operator from recognizing an incorrect measurement result. In the present invention, a level detecting circuit detecting a signal level of an oscillation output of an oscillator circuit is provided, and after the time for stabilization passes after the power-on time, a computer takes a level detection value therein to compare the signal level and a threshold value. Then, when the signal level is lower than the threshold value, the signal level is determined as abnormal and, for example, the abnormality notification is displayed on a display unit, whereby an operator is notified of the occurrence of the abnormality.

Abstract: To enable successive measurement of samples by using one piezoelectric sensor. An adsorption layer provided in a piezoelectric sensor is an adsorption layer in which protein and an immunoglobulin are stacked in this order from the bottom. The immunoglobulin has a property of separating from protein when coming into contact with an acid liquid, and therefore, when the immunoglobulin as the adsorption layer is brought into contact with the acid liquid after capturing a substance to be sensed, the immunoglobulin is separated from the protein. Then, the adsorption layer is again formed by the supply of a new immunoglobulin, which enables the successive measurement of samples.

Abstract: In adopting a structure in which an oscillator circuit unit and an instrument main body including a measuring unit are separately formed in a sensing instrument measuring the concentration of or determining the presence/absence of a substance to be sensed by using a quartz sensor, the present invention has an object to enable the instrument main body side to know an oscillation frequency of the connected oscillator circuit unit.

Abstract: It is an object of the present invention to provide a PLL apparatus realizing extremely high frequency stability. As a concrete means for solving the problem, an A/D (analog/digital) conversion unit samples a standard signal based on a 40 MHz frequency signal, which is a rectangular wave, from an oven-controlled crystal oscillator (OCXO), and an orthogonal transformation unit applies orthogonal transformation to a digital signal from the A/D conversion unit to extract a real part (I) and an imaginary part (Q) which are complex expression of a phase vector equivalent to a phase difference between the standard signal and the frequency signal from the OCXO. An angular velocity of this vector is detected and a direct-current voltage according to the angular velocity is generated and supplied to the OCXO via a PWM control unit.

Abstract: An object of the present invention is to provide a highly sensitive Langevin type quartz sensor which is easy in assembling, is less likely to cause damage to a quartz resonator during the assembly work, and is easy to perform a measurement work. As a specific means to solve the problem, a recess is formed in a quartz holding member made of, for instance, rubber, and an airtight space is formed by holding the quartz resonator with the quartz holding member so as to cover the recess. In the meantime, a hole is provided in a circuit board and a projected portion which projects toward back side of the recess in the quartz holding member is fitted into this hole.

Abstract: An object of the present invention is to perform measuring work easily when detecting the presence or absence of an object to be measured or the concentration thereof using a plurality of quartz sensors equipped with a Langevin type quartz resonator. As a concrete means for solving the problem, a quartz sensor 3 equipped with a quartz resonator 30 forming an adsorbing layer to adsorb a target component to be measured on one surface side and coming into contact with an airtight space on the other surface side is installed in a printed circuit board 4 via a base 5. A plurality of quartz sensors 3 is detachably installed respectively in a plurality of connecting terminal units provided in a horizontal arrangement on a side surface 21 of the measuring device main unit 2 via a connecting terminal unit 41 formed on an end of the printed circuit board 4 in a state that the above-described adsorbing layer faces upward.

Abstract: It is an object of the present invention to provide a PLL apparatus outputting a frequency signal from a voltage-controlled oscillation unit in synchronization with an external reference frequency signal, in which the fluctuation of the frequency is reduced even when the external reference signal has a trouble. As a concrete means for solving the problem, as a result of monitoring the signal level of the external reference frequency signal, when its signal level falls within a set range, data regarding a phase difference created by a phase difference data creating means is used for the PLL control, but when the signal level does not fall within the set range, it is recognized that the supply of the signal has been stopped or the supplied signal has abnormality and the data regarding the phase difference stored in a storage unit, for example, the stored latest data or the pre-created data is used instead for the PLL control.