To establish a temperature measurement system, electronic temperature instrument needs to be wired to control system . RTD and thermocouple can be directly connected to control system I/O card or through Temperature Transmitter for signal conversion. In most application, temperature transmitter is used to convert RTD/Thermocouple signal and transmit 4-20mA signal, rather than directly wired the RTD or themocouple to I/O card.
Advantages to Use Temperature Transmitter
The choice of using temperature transmitter over direct wiring of RTD or thermocouple to control system provides many advantages:
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The signals generated by Resistance Temperature Detector or Thermocouple are categorized as low-level signal hence it is more susceptible to noise compared to conventional 4-20mA signal generated by transmitter.
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Reduce instrument cable type. It also means less type for cable spare.
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The junction box for thermocouple temperature transmitter cables can be combined with those from other 4-20 mA transmitters.
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No need to provide special I/O card for thermocouple/RTD. Just connect the Transmitter to the Analog Input I/O card.
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Provided maintenance facilities such as diagnostic feature in smart transmitter.
