Choosing & Installing Best Temperature Monitoring Device and How it Works

A wrong or doubtful Temperature Monitoring Device can have very costly consequences.

The transmitter is directly linked to the thermocouple, or RTD leads, converting the input signal to an output signal with a range of 4 to 20 mA, 0 to 10 Vdc, or a digital output signal like RS232, RS485. This is sent via a twisted pair wire wherever it has to be shown or recorded.

There are many different types and levels of sophistication for temperature transmitters, ranging from small, DIN rail-mountable units to programmable, "smart" devices with diagnostic capabilities.

The Benefits of Temperature Transmitters

Direct connecting of Temperature Monitoring devices to data logging or display equipment was customary in the past. Engineers are starting to understand the advantages of employing temperature transmitters, though.

• Less costly wiring. 

Thermocouple extension cables are typically more expensive and more delicate than regular twisted pair cables since they are typically composed of the same material as the device itself. Since twisted pair is simpler to install and costs less per meter overall, there are significant long-term benefits.

• Easier maintenance. 

Cable breaks and shorts are less frequent and clearly identifiable when they do happen with twisted-pair cables because they can endure severe environments better. Since "smart" transmitters may transmit diagnostic data, issues can be identified before a technician begins tracing wires and searching for problems.

• Flexibility in updating and improving. 

If the process changes after the temperature transmitters are placed, and new thermocouples are required, only the sensor itself needs to be changed. On the other hand, existing direct cable connections can be used to establish a transmitter (although EMI immunity would be lower).

How to decide on a temperature sensor device?

• A meeting spot. 

Will it be repaired? Will it be a public area? Will it be a risky area?

• Value of maintaining signal integrity. 

If a measurement mistake has the potential to be expensive, seek for a transmitter with good isolation.

• The requirement for programming ability. 

Find this type of transmitter if set points and scaling are critical considerations.

• A requirement for "smart" abilities. 

These temperature transmitters have the ability to generate alarms in the event of abnormal circumstances and offer diagnostic data that facilitates quick maintenance.

Conclusion: A temperature transmitter is an amplifier that filters, conditions, and amplifies the signal's power to improve reception at the place where the temperature is being measured.