Instrumentation ITRs document the calibration and functional verification of measurement and control devices. These records ensure process control systems operate accurately and safely.
Types of Instrumentation ITRs
Calibration Records
Document instrument calibration with as-found readings, adjustments made, as-left readings, accuracy verification, and calibration due dates.
Loop Check Records
Verify complete loops from field device through control system including signal path verification, scaling confirmation, and control action validation.
Functional Test Records
Document functional testing of control valves, safety instrumented functions, and control logic.
Calibration Data Requirements
Standard Data Points
- Instrument tag and description
- Manufacturer and model
- Calibrated range
- Test points (typically 0%, 25%, 50%, 75%, 100%)
- As-found and as-left values
- Error calculations
- Pass/fail determination
SIS Documentation
Safety Instrumented System ITRs require additional rigor with SIL verification, proof test documentation, and demonstrated independence.
Best Practices
- Use instrument datasheets as ITR source
- Document test equipment with calibration status
- Include environmental conditions during calibration
- Maintain calibration history for trending
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