DIN RAIL MOUNTED TEMPERATURE TRANSDUCER
DIN rail replaces 19-inch technology
Temperature is one of the most important process parameters for refining crude oil. Replacing the temperature transducers installed in the 1980’s has been a topic at the BP refinery in Lingen, Germany. In contrast to the 19-inch transducers used during its time in the control room, in this project, BP Lingen is upgrading to modern interface devices for DIN rail assembly. “The 19-inch technology is disappearing from our plants more and more because a DIN rail solution in our case is simply more cost effective and the assembly time considerably lower,” says Nitschke. “When necessary, I can replace devices from different manufacturers without any problem – I simply remove the old device from the rail and place the new one on it, add voltage supply, signal input and output, and finished.”
Despite the many products to choose from, when replacing their 19-inch technology, the BP specialists intentionally selected the IM34 temperature transducer from Turck: “At that time, we looked at the products from leading suppliers and subsequently decided in favor of Turck,“ explains Holger Nitschke. “In addition to an excellent cost/benefit ratio, the compact design and the simple assembly were important for us because space in the control room is becoming increasingly expensive.”
Modernizing temperature measurement technology does not necessarily have to mean a completely new installation, as the example of the Lingen refinery shows. With the right technology, today’s requirements can be met by simply replacing the temperature transducer. “In the past, we performed many temperature measurements via type K thermocouples. That is why even in the older plants there is a high number of nickel-chromium/nickel cables between the control rooms and the plant. All of the existing wiring in the plant – including the sensors – can continue to be used,” explains Nitschke.
IM34 processes various input signals
In addition to thermocouples, Pt100 temperature sensors, based on the resistance change in platinum under the influence of temperature, are being increasingly used in process automation today. As a resistance thermometer for the temperature range of -200 to 500 °C, the Pt100 is more precise than a thermocouple. In contrast, the thermocouple, is suitable for a larger temperature range. Regardless of which measurement process is used, as a universal temperature transducer, the IM34 processes input signals from Ni100/Pt100 resistances, as well as thermocouples or millivolt signals. The device combines this universal capability with the high functionality of a freely parameterizable data logger and a PC interface for simple programming. The DTM (Device Type Manager) for the IM34 was developed in accordance to the current design guidelines of the FDT group.