Corrosion data logger: Identify problem situations in real-time

Diagnose process conditions that promote equipment corrosion.
By Control Engineering Staff September 18, 2008

Portable data logger can be moved to multiple locations.
Corrosion data is normally considered a long-term effect, but a new device from Pepperl+Fuchs helps identify and diagnose situations where corrosion potential rises due to process upsets or changes.

The CorrTran corrosion data logging system is a Division 2 / Zone 2 data logger designed to operate with the CorrTran MV online corrosion monitoring sensor and transmitter. Adding the new device to the sensor reportedly allows users to access real-time corrosion data via Ethernet, USB, SD card, or locally via videographic chart recorder. The data logger is packaged in a portable, stainless steel enclosure weighing less than 20 lbs. Operators can leave it in one spot or move it as required among multiple sensors.

“CorrTran MV represents a major advancement in internal corrosion monitoring by detecting and measuring, online and in real-time, the presence of general corrosion, as well as pitting corrosion and conductance,” says Jason Norris, product manager. “The transmitter outputs a 4-20 mA HART signal that is used to scale the corrosion rate in a PLC or DCS system. The key advantage here is that the rate of corrosion can now be evaluated with all other relevant process signals. It has always been known that specific process conditions will cause increased rates of corrosion but often this is known after-the-fact. Imagine controlling corrosion inhibitors, and thus controlling costs, by viewing corrosion data online, and in real time.”

The corrosion data logging system includes Pepperl+Fuchs’ new HART loop converter. The company says this device receives HART data from the CorrTran MV corrosion monitor and delivers three distinct 4-20 mA outputs that represent general corrosion, localized corrosion, and conductance. These three variables can then be recorded and displayed on a paperless data recorder that features a full color touch screen display, up to 16 analog inputs, multiple types of media retrieval, and a Class I / Div 2, Zone 2 Ex-hazardous rating. A Type 4X stainless steel enclosure is suited for severe installations. The lightweight construction also permits easy mobility for the system to be moved from one location to another, where a PLC or DCS might not be available.

—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com ,
Control Engineering Process Instrumentation & Sensors Monthly
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