Pressure Calibrator Troubleshooting and Accuracy Verification Guide
Maintaining the accuracy of pressure calibrators is essential as they serve as the reference standard for calibrating field instruments.
I. Accuracy Verification
- Cross-Comparison: Compare the calibrator against another calibrated reference standard of equal or better accuracy at multiple pressure points.
- Deadweight Tester: For pneumatic calibrators, use a deadweight tester as the primary pressure standard. This is the most accurate method for pressure calibration.
- Verification Frequency: Perform accuracy verification at least quarterly if the calibrator is used regularly. Increase frequency if used in dusty or high-vibration environments.
II. Common Problems
Pressure Drift: Check for internal leaks in the pump or manifold. Verify that the reference sensor is not damaged from overpressure. Allow adequate warmup time.
Cannot Build Pressure: Check that the vent valve is closed. Inspect for external leaks at fittings and connections. Verify pump seals are intact.
Display Errors: Check battery level on portable units. Verify that the calibrator is within its specified operating temperature range.
III. Preventive Maintenance
- Replace seals and O-rings annually or per manufacturer schedule
- Clean or replace filters on pneumatic calibrators monthly
- Store in a clean, dry environment when not in use
- Use protective carrying cases for portable calibrators during transport
