Abstract: A wireless equipment diagnosis system which can perform inspection and maintenance precisely and accurately, and which comprises sensors which measure information on each equipment being diagnosed, a transponder which transmits measured data from the sensors after modulating the measured data; a portable interrogator which acquires the measured data by receiving transmitted signals from the transponder; and a host computer which diagnoses each equipment by implementing predetermined signal processing using information stored in advance and data transferred from the acquired data.

Abstract: A small-sized antenna device is used for portable telephone equipment and is capable of preventing the receiving strength from being degraded due to a change in the application environment as well as the mounting thereof onto a small radio equipment case. The antenna device has a linear antenna for producing an electric current flux and a coil-shaped antenna for producing a magnetic current flux including a plurality of half-wavelength helical coils connected in series so as to have two adjacent coils coiled in opposite directions with respect to each other, and carries out polarization diversity. Degradation in the characteristics of both antennas due to differences in operational principle can be prevented from taking place simultaneously, resulting in realizing a good reception of a radiowave. In addition, the antenna axes of both antennas can be disposed in parallel and close to each other, thus miniaturizing the device itself.

Abstract: An electromagnetic flowmeter is energized by a tri-state excitation system having a first quiescent period, a first excitation period, a second quiescent period, a second excitation period for excitation with a polarity opposite to that of the first excitation period, and a third quiescent period. The electrode signals are sampled at equal intervals in each period except the second quiescent period and combined to provide an output which eliminates noise due to residual magnetic flux, electrochemical effects and commercial frequency.

Abstract: A signal generator for an electromagnetic flowmeter provided with a flow tube having an insulated liner through which a fluid to be metered flows to intercept an electromagnetic field established therein to induce a signal depending on flow rate in a pair of electrodes mounted at diametrically-opposed positions on the tube. The field is created by an excitation coil to which is applied an excitation current derived from an external power supply. This signal generator incorporates a current-setting circuit for setting the excitation current to a value establishing a constant relationship between the flow rate of the fluid and the signal yielded by the electrodes.