Referred to the current "ultrasonic" kind of instrument, sonicator homogenizer is inseparable from the topic of a transducer ", but "output", ultrasonic heat meter and ultrasonic flow meter as a kind of ultrasonic class instrument, transducer and the output signal is very important for the two plates.
First is the ultrasonic heat meter transducer, ultrasonic heat meter can realize heat metering, there are two important factors, one is ultrasonic heat meter flow metering work can be accomplished, the other is ultrasonic heat meter can realize the temperature measurement. In the process, transducer plays a very important role.
As the basis of ultrasonic heat meter flow measurement, the role ultrasonic molten metal of the ultrasonic transducer is to convert electrical signals into ultrasonic signal or the ultrasonic signal into electrical signal. Currently using piezoelectric ultrasonic transducer, ultrasonic transducer is mainly using piezoelectric effect and inverse piezoelectric effect produce and receive ultrasonic signals. The flow measurement of ultrasonic heat meter transducer often do is done using the transmitting transducer and receiving transducer is used, called transceiver combined type transducer, the design of this kind of transducer and the performance parameters of the characterization to juggle and reflect the characteristics of transmitting and receiving.
For now, the ultrasonic heat meter transducer used in piezoelectric materials is a piezoelectric ceramic, the piezoelectric material not only excellent piezoelectric properties, but also can exert or absorb a certain amount of stress, and the price is ultrasonic spray nozzle relatively cheap, occupy the dominant position of piezoelectric materials.
Followed by the output signal of ultrasonic flowmeter, ultrasonic flowmeter is currently used in industry site very much flow meter, flow meter voltage signal is not stable, sometimes in long distance transmission by simple interference, and the current signal is relatively stable. So choose the current signal transmission process, at the same time, choose to voltage signal (voltage) is used to control the instrument (accumulator) and DCS control in detail.
Normally, because 0 ~ 20 ma range of the signal cannot be apart from the fault signal is less than 4 ma said line is faulty, or suspected of zero drift, so the birth of two-wire meter driven by the great changes in specifications, new specifications for 4 ~ 20 ma current signal.
Dual sensor set the ultrasonic welding transducer specifications of 4-20 ma, during this period 0 to 4 ma current is needed to provide the minimum working current sensor itself. If you choose to 0 to 20 ma, when the signal is very small, the sensor will not be able to obtain satisfactory work energy. In fact, in about 4 ~ 20 ma signal, the DCS system usually count is greater than 20.2 ma is less than 3.8 milliampere as failure.