๐ CALIBRATION GUIDE: Salwico SW2020 Fixed Gas Detection System
Complies with SOLAS, ISM, PSC requirements • Ready to follow step‑by‑step
⚠️ BEFORE YOU START
- Safety first: Work in ventilated area; wear PPE; isolate alarms if needed; inform bridge/engine control
- Tools & gases required:
✅ Zero gas: Clean dry air (for flammables) or 100% Nitrogen N₂ (for O₂)
✅ Span gas: Certified mix matching target gas (e.g., 50 %LEL Propane, 20 ppm H₂S, 20.9 % O₂) — within expiry date
✅ Calibration kit, sample tubing, flowmeter, system manual, logbook
- Frequency: Per Company PMS / SMS — typically every 3–6 months, or after service/repair, or before PSC inspection
Refer to you ship Specific Equipment Manual and Company Management System.
๐️ STEP‑BY‑STEP CALIBRATION (From Control Unit)
1. Enter Calibration Mode
- Power ON, system stable; navigate to Main Menu → Service → Calibration
- Select Span Calibration (Menu 13) first, then Zero Calibration (Menu 14)
2. Span Calibration (Adjust Sensitivity)
1. Choose detector number (1–4) → press F1 CONTINUE
2. Enter exact span gas concentration printed on cylinder → F1
3. Connect test gas line to analysing unit test port; set flow to ~0.5–1 L/min
4. Open cylinder valve → F1 START; wait 2–3 minutes for readings to stabilize
5. When steady: press F1 CALIBRATE → confirm success message
6. Close gas valve; disconnect line → F1 EXIT
7. For O₂: Use 20.9 % O₂ span gas; follow same path — menu labels differ slightly
3. Zero Calibration (Set Baseline)
1. Go to Menu 14 Adjust Zero → select detector → F1
2. Flammable/Toxic: Use clean air; O₂: Use N₂ only
3. Open zero gas supply → F1 CONTINUE; wait for reading to settle
4. Press F1 ADJUST → confirm → close valve → F1 EXIT
5. Final step: Return to Menu 11 Save Setup — always save after calibration!
4. Manual Calibration (For 4–20 mA Detectors)
- Disconnect sampling; connect multimeter to terminals M1(+) / M2(–)
- Zero: Apply clean air/N₂ → adjust P2 to 4.00 mA
- Span: Apply certified gas → calculate target:
Target mA = (16 mA ÷ FullScale) × GasValue + 4 mA
Adjust P1/P3 until matched; secure cover
✅ VERIFY & RECORD
- Test with known gas; confirm alarms trigger at correct levels
- Log mandatory details: Date, time, gas used, concentrations, readings before/after, technician name, expiry date of gases
- Keep certificates & logs ready for PSC / Class inspection
❌ IF CALIBRATION FAILS
- Check gas cylinder not empty, tubing not blocked/leaking, filters clean, pump flow normal
- Verify sensor not expired or contaminated; replace if needed, then retry
๐ PSC COMPLIANCE TIPS
- Calibration must be current; logs complete; system shows no faults
- Crew must demonstrate how to calibrate and test — inspectors may ask
- Alarms, sampling sequence, and valve operation must work correctly