Thus, conventional transmitters and switches can severely compromise a system's integrity. The Moore XTC critical transmitter is TöV certified for high availability and safety applications.
The critical transmitter combines Moore's proven Quadlog safety PLC (since 1995) with the capsule and sensor technology proven in XTC transmitters (since 1990). As such, the transmitter's critical pressure measurements provide a proven method to reduce downtime in specialty chemical and pharmaceutical applications and increase protection for the chemical, petrochemical and oil and gas industries in a variety of control and safety applications.
Quadlog features for failsafe operation include hardware and software redundancy, a comprehensive self-testing system and primary and secondary current sources to ensure safe fault indication. The critical transmitter includes the XTC family's patented MycroSENSOR for high accuracy. These capabilities minimise cost of ownership via reduced installation and maintenance costs. The transmitter's TöV certification ensures that it meets the world's toughest safety standards.
Because the transmitter is a member of the XTC family, it also seamlessly integrates with the APACS+ process automation system and the companion Quadlog safety PLC to provide a total plant solution.
Exploiting proven technology
The XTC critical transmitter is based on Quadlog's proven architecture which includes dual processors with comprehensive self-tests and a secondary shutdown path controlled by diagnostics. The critical transmitter includes both sense and reference sensors to compare and verify the pressure capsule's health. It also features diverse microprocessors, two microprocessors using dissimilar technology to avoid common cause which calculate and verify pressure range for failsafe operation. The transmitter automatically switches to its built-in secondary current source when its diagnostic circuitry detects any number of internal or external failures. These features which are specific to the XTC critical transmitter, appear in red in the diagram below.
The transmitter's unique capabilities allow a single critical transmitter to be installed where two conventional transmitters are usually installed in a critical application (or two critical instead of three conventional) which reduces installation and maintenance costs.
Agency approved for greater confidence
To provide greater confidence, the transmitter carries all standard XTC certifications, plus functional safety approval from Germany's TöV organisation. TöV is the only international agency that approves safety systems and instrumentation design for avoidance and control of errors, faults and human mistakes. It rates this equipment for requirement class levels (AKs) to specify the amount of safety risk reduction required by a particular application. TöV AK levels range from a 0 (no safety provisions required) to an 8 (most dangerous processes); these are roughly parallel to ISA S84.01 safety integrity levels (SILs) 1-4, TöV AK levels compare to S84's SIL levels as follows:
* AK 1-3 to SIL 1.
* AK 4 to SIL 2.
* AK 6-5 to SIL 3.
* AK 8-7 to SIL 4.
Integrating for a total solution
The XTC critical transmitter can operate standalone or within a plant automation or safety system. As a member of the XTC family, it does not require any communication interfaces to be used in conjunction with Moore's other instruments and systems. This allows APACS+ process automation system and Quadlog safety PLC users to simply configure and install the critical transmitter, enhancing the systems' ability to deliver a comprehensive solution for critical processes.
Minimising total cost of ownership
Because a single XTC critical transmitter provides the same level of protection as two conventional transmitters, it reduces cost of total ownership by over 50%. In addition, the XTC transmitter's self testing capabilities eliminate the need for calibration maintenance which is typically performed twice a year on a conventional transmitter.
The no-drift silicon sensor and extensive self-checks via redundant processors deliver a high level of confidence. This confidence which is fortified by the transmitter's ability to provide complete loop integrity via output checking and verification, means increased system availability.
| Tel: | +27 11 466 1673/9 |
| Email: | [email protected] |
| www: | www.moore.co.za |
| Articles: | More information and articles about Moore Process Controls |
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