Keep analysers running

What you will be able to do

• Calibrate correctly and know what the adjustment did
• Choose and handle calibration gas without introducing error
• Set a calibration interval you can defend
• Diagnose a reading that is high, low, noisy, slow or stuck
• Plan spares and sensor replacement

Follow these lessons in order

1. Accuracy, precision, repeatability and drift in gas analysersAccuracy is how close a reading is to the true value; precision or repeatability is how closely repeated readings agree; drift is how the reading moves over time.Know what drift is before fighting it.Intermediate3 min
2. How gas analyser calibration works: zero and spanCalibration compares the analyser's reading with a gas of known concentration and adjusts it to match.Zero and span, properly.Beginner4 min
3. Calibration gases: choosing, handling and certificatesChoose span gas near 70 to 90 % of the range in a balance gas that matches the sample, with a certificate stating concentration, uncertainty and expiry.Bad gas makes a bad calibration.Intermediate3 min
4. How often should you calibrate a gas analyser?Set the interval from three things: how much error the process can tolerate, how fast the analyser drifts, and what a wrong reading costs.A risk-based interval.Intermediate3 min
5. Auto-Calibration and validation checks for gas analysersAuto-calibration switches zero and span gas to the analyser by solenoid valves on a timer, keypad or Modbus command, and adjusts or records the result.What to automate and what not to.Intermediate3 min
6. Troubleshooting gas analyser readings: high, low, noisy, slowApply known gas at the analyser inlet.Symptoms to causes.Intermediate3 min
7. Sample system troubleshooting: symptoms to causesMost analyser faults are sample system faults.Most faults are in the sample.Intermediate3 min
8. Sensor life, poisoning and replacement in gas analysersElectrochemical cells are consumed by the gas they measure and last months to years depending on exposure.Know the end of life.Intermediate3 min
9. Maintenance schedule and spares for gas analysersMaintain analysers by routine: a daily look at flow, pressure and condensate; a weekly check of filters and drain; a monthly calibration check; and an annual full calibration, sensor check and leak test.Put it on a schedule.Intermediate3 min

Stuck on a real problem while you learn? Ask an engineer. Every lesson is checked against the figures in our catalogues.