Solving Temperature Measurement Challenges in Hazardous Zones
Engineers working in oil refineries or chemical plants often face a critical pain point: how to accurately measure temperature in Zone 2 hazardous areas without compromising safety or signal integrity. The ABB AI950B analog input module directly addresses this challenge. It supports Pt100, Pt1000, and Ni100 RTDs in 2-, 3-, or 4-wire configurations, as well as thermocouples types B, E, J, K, L, N, R, S, T, and U. This flexibility lets you handle diverse sensor types with a single module.
Key Technical Specifications and Their Practical Meaning
The AI950B provides four isolated input channels, each electrically isolated from the bus and from power. Channel-to-channel isolation prevents ground loops and cross-talk, which is essential in noisy industrial environments. The module also includes internal or external cold junction compensation for thermocouples, ensuring accurate readings even when ambient temperatures fluctuate. Short-circuit and break detection further enhance reliability by alerting operators to sensor faults immediately.
Rated for an ambient temperature range of -20 °C to 60 °C and a relative humidity of up to 93% at 40 °C, the AI950B withstands harsh conditions. Its G3 coating per ISA-S71.04 protects against corrosive atmospheres, making it suitable for offshore platforms and chemical processing units. The module measures 20 mm wide, 104 mm deep, and 104 mm high, with a weight of only 0.135 kg, so it fits compactly into S900 I/O racks.
Integration with PROFIBUS DP Networks
The S900 I/O system communicates with the control system via the PROFIBUS DP standard. This fieldbus protocol is widely adopted in process automation, enabling seamless data exchange with ABB and third-party controllers. The AI950B supports HART protocol, allowing you to access additional device diagnostics and configuration parameters from smart transmitters. Redundant power and communication options are available, which minimizes the risk of a single point of failure in critical loops.
Real-World Application Example
In a typical petrochemical distillation column, temperature monitoring at multiple tray levels is essential for product quality. The AI950B connects directly to Pt100 RTDs installed in Zone 1 or Zone 0 areas via intrinsic safety barriers. Its channel-to-channel isolation ensures that a fault on one sensor does not affect the others. The hot swap functionality lets you replace a faulty module without powering down the entire system, reducing unplanned downtime.
Why Choose CtrlTechDaily for Your ABB AI950B
CtrlTechDaily stocks the ABB AI950B (article number 3KDE175522L9500) and can provide fast delivery for both new projects and emergency replacements. Our team understands the importance of lifecycle support for legacy systems. Please verify current lifecycle status and availability with CtrlTechDaily before ordering to ensure the module meets your project timeline.
What certifications does the AI950B hold?
The AI950B carries ATEX certification for Zone 2 hazardous locations. It also complies with RoHS Directive 2011/65/EU and WEEE Directive 2012/19/EU. The module is designed for corrosive environments per ISA-S71.04 G3 classification.
Can the AI950B be used with intrinsically safe sensors?
Yes, the AI950B is designed for connecting intrinsically safe field devices installed in Zone 2, Zone 1, or Zone 0. It provides electrical isolation between input and bus, as well as between input and power, which is necessary for intrinsic safety applications.
Does the AI950B support redundancy?
The AI950B itself does not support redundancy at the module level. However, the S900 I/O system offers redundancy options for power and communication. For redundant I/O configurations, you would need to use two separate AI950B modules and manage the redundancy at the system level.
