Enhance Safety Proof Test Intervals (PTI) Safety Instrumented Systems (SIS) perform specified functions to achieve a safe state of process when dangerous conditions occur. It is their aim to mitigate consequential events. Loops of Safety Instrumented Systems consist of • Sensors • Logic solvers (processing the sensor signal and giving outputs) • Final elements (taking action to bring the process to a safe state, e.g. safety shutdown) Regulatory requirements According to the IEC 61511 Lifecycle Concept, many SIS specific monitoring and test activities are required to maintain the desired level of safety integrity, i.e. Safety Integrity Level (SIL). This validation is called Proof Test Interval (PTI) and has to be carried out on a regular basis. Proof tests must be conducted as defined procedures that ensure tests are done correctly and systematically. Failed devices must be repaired or exchanged to achieve completely reliable process safety.
Monitoring rotating equipment The population of rotating equipment in the process industry is huge. Pumps, compressors and auxiliary systems are integral parts of the production process. Many of these are rated as “critical” and call for a reliable and adequate safety protection system. The most commonly used method for condition monitoring and safety protection of rotating machines is vibration analysis with velocity, acceleration and proximity sensors. PROGNOST-SenSim is the first and only product available that is able to simulate sensor outputs, including their electrical behavior producing realistic static and dynamic signals.
PROGNOST-SenSim is a portable device for the simulation of sensor signals. It simulates static and dynamic signals for measuring loop test routines. Sensor simulation capabilities • Simulation of sensors with separate setting for static and dynamic signal components • Simulation of full sensor measuring range • Predefined Sensor library including most commonly used Eddy Current and Acceleration / Velocity Sensor Types • User conveniently apply values in units they regularly deal with (g’s, inch/sec, mil, bar etc). eliminating the need for complex electrical conversion into mV, mA etc. PROGNOST-SenSim simulates sensors with the following signal types: • 4 … 20 mA – Simulates for example pressure, temperature, f l ow, level transmitters. • *ICP/IEPE – Simulation of dynamic ICP/vibration signals. The signal is phase-referenced, i.e. simulated per revolution over 360° crank angle. • Eddy Current – Overlaying static signals with dynamic signals allows to simulate the dynamic piston rod position of a reciprocating com pressor and dynamic shaft position of other rotating equip ment (e. g. centrifugal compressors, gas turbines or pumps). • Voltage – Simulation of +/– 10 V voltage for norm signals in the fi eld of measurement and control technologies. • Trigger – Rotation speed simulation, from 30 up to 65.000 rpm is possible. • Pulse (Lube Oil) – for simulation of lubrication instrumentation, e.g. Loft 600, KIS and Kracht. • Strain Gauge – indirect pressure measurement at high pressure compressors (Hyper). * ICP (integrated circuit piezoelectric) IEPE (integrated electronics piezoelectric)
Realistically testing of safety protection functions and algorithms • 2ooX voting • Signal plausibility check • Counting of consecutive revolutions with safety limit violation (phase referenced signal) Eliminating the risk of sensor damage The testing procedures can be carried out without taking off the sensors. This eliminates all associated risks, such as sensor damage or recalibration issues. Adjustable to any desired frequency and amplitude The defined and precise violation of real safety limit-settings makes the execution of PTI (Proof Test Interval) compliant to IEC regulatory requirements (no manipulation of safety limits to initiate Alert / Shutdown / Unsafe conditions).
VSST (Valid Speed Safety Test) The VSST is especially designed for performing the PTI on systems designed for monitoring reciprocating machinery with Segmented Vibration Monitoring. While PROGNOST®-SILver monitors every revolution subdivided into 36 or 8 segments, this functionality helps to realistically simulate ALERT and SHUTDOWN situations by violating a selected number of segmented safety limits over a defi ned number of consecutive revolutions. Additionally it can simulate a signal out of range situation, important to test the systems capability of detecting UNSAFE conditions of the monitoring system itself. The TDC off set setting helps to confi gure the Trigger signal exactly referenced to the TDC of the cylinder under test.