Measuring the interface between two liquids in a tank presents unique challenges Finding the interface between two liquids in a tank is critical for some processes. A common measurement in the oil & gas, chemical, and petrochemical industries is detecting the interface level between two liquids in the same tank or vessel, such as oil [...]
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Steam temperature controls standard reaffirmed for 2012
The power industry has seen various steam temperature control systems developed over the years to fit the needs of particular applications in the fossil fuel power industry. Plants must consider operating philosophy, plant layout, and type of firing before they ultimately select a system. They do not need a standard that limits the complexity or [...]
Fossil Fuel Committee Publishes Functional Requirements
Organizations that operate fossil fuel plant control room simulators deal with different operator and training practices. Yet they share common goals when it comes to personnel safety, maximum equipment availability and lifetime, and ensuring efficient operations. When the ISA77.20 subcommittee reviewed the existing standard, ANSI/ISA77.20.01, Fossil Fuel Power Plant Simulators: Functional Requirements, they updated many [...]
ISA12 Hazloc Standards Members Gather for Intensive Week of Meetings
Veteran and novice ISA12 (Electrical Equipment for Hazardous Locations) Members will gather in Orlando, Florida March 12-16 to cover topics such as intrinsic and increased safety, encapsulation, gas detectors, fiber optics, and installation, maintenance, and repair. ISA12 covers the work of 40 standards, including 25 adoptions of IEC standards. The week will include review of [...]
Uninterruptible power supplies, cybersecurity
… Once a hacker has gained access to a moderately secured network, they can easily determine the IP addresses of every device on the network. Using port scans, they then can determine if the device communicates through HTTP, SNMP, Telnet, MODBUS, etc. Once the communications protocol has been established, the hacker will first attempt to [...]
Making Sense of MEMS
Micro Electro Mechanical Systems (MEMS) describe a type of device or sensor as well as a manufacturing process. MEMS sensors incorporate tiny devices with miniaturized mechanical structures, typically ranging from 1-100 μm (about the thickness of a human hair), while MEMS manufacturing processes provide an alternative to conventional macro-scale machining and assembly techniques. … MEMS [...]
Guide lines for the tuning and the evaluation of decentralized and decoupling controllers for processes with recirculation
Abstract: This paper gives guidelines for the pairing, the time response specification, and the tuning for processes with recirculation when decentralized controllers are used. This selection is based on the condition number, which is an indicator of the process directionality, and on the generalized dynamic relative gain (GDRG), which is a measure of the interaction. [...]
Security standards committee completes ballot
The ISA99 committee recently completed a ballot on the standard, ISA-62443.03.03 (99.03.03), Security for Industrial Automation and Control Systems: System Security Requirements and Security Assurance Levels. Closing on October 27, 2011, the ballot passed with 18 approval votes and five disapproval votes. Reflecting the widespread interest in the draft, more than 500 comments were received [...]
New Enterprise-Control System Integration Standard Issued for Review/Voting
A new draft standard in the widely used ISA-95 series has been issued for ISA95 committee balloting, as well as ISA and ANSI public review. ISA-d95.00.04, “Enterprise-Control System Integration: Part 4: Objects and Attributes for Manufacturing Operations Management Integration,” defines business-to-object models and attributes of the object models that define some of the information exchanged [...]
AD Converters
AD Converters AD Converters are necessary to convert an analog signal to a digital one that our computers can understand. The output of an AD Converter is a binary number.Digital instruments most commonly use 12, 14, and 16 bit converters, although there are much higher bit converters available. The following is a practice [...]