THE YTA Series of temperature transmitters from Yokogawa Australia has been upgraded to SIL certification as standard. Improvements have also been made to the transmitters' trimming point and input signal functions.
The YTA Series temperature transmitters range includes YTA50, YTA70, YTA110, YTA310 and YTA320 models. All are certified to SIL 2 for single use installations and SIL 3 for dual transmitter use.
All models accept thermocouple, RTD, ohms or dc millivolts user-selectable inputs and convert the sensor signals to a unified signal, 4 to 20mA signal or Foundation fieldbus. This eliminates the drawbacks of wire resistance and signal noise that are often experienced with conventional temperature instruments, which must be connected by long extension lead wires or three-conductor cables to converters in an instrument panel room.
The YTA Series utilises microprocessor-based sensing technology to ensure high signal accuracy and reliability. All models are manufactured with a dual-compartment housing for high resistance to harsh operating environments.
The Series supports the Hart/Brain communication protocol. According to Yokogawa, the instrument configuration can be changed by site technical personnel, using the BT200 or Hart communicator, to suit local conditions and requirements. An additional feature is that both the sensor type and the measurement range can be selected.
A continuous self-diagnostics capability in each model is designed to ensure long-term performance and lower cost of ownership. A backlit LCD display provides both a digital readout and percentage bar-graph display simultaneously.
Individual models in the range provide additional standard features including RTD sensor functions (on the 310 and 320 models) and dual inputs on the YTA320, which allow a differential or average measurement or utilisation of the second sensor as back-up.
The sensor trimming function on all models has been upgraded to accept only zero point trimming and temperature sensor input. The trimming point now recognises zero or zero and gain (previously zero and gain only) and all YTA transmitters now recognise input signals from dc voltage generators, variable resistors or temperature sensors.