Petroleum testing
Copper Strip Corrosion Bath
A thermostatic bath that holds a polished copper strip immersed in a fuel or oil at a set temperature (for example 50 °C or 100 °C) for a set time. The tarnished strip is then compared with the ASTM colour standards to grade corrosiveness.
- Petroleum refining
- Fuel terminals
- Lubricant blending
- Aviation fuel quality
- Independent testing laboratories
TROUBLESHOOTING
Common problems, causes and fixes
Stains or uneven colour on strip
Likely causes
- • Fingerprints
- • Poor polishing
- • Water in the sample
- • Strip not fully immersed
What to do
- • Handle only with forceps
- • Repolish carefully along the length
- • Dry or note water in the sample
- • Use the correct sample volume
Results vary between repeats
Likely causes
- • Bath temperature unstable
- • Different polishing technique
- • Timing errors
What to do
- • Check and adjust bath control
- • Standardise polishing procedure
- • Use a timer for the 3 h period
Sample lost from pressure vessel
Likely causes
- • Worn seal
- • Cap not tightened
What to do
- • Replace seal
- • Tighten to the manufacturer's instruction and recheck
Unexpected high class for a normally good product
Likely causes
- • Contaminated wash solvent
- • Contaminated test tube
- • Genuine active sulphur
What to do
- • Use fresh sulphur-free solvent
- • Use clean glassware
- • Repeat; investigate the product batch if confirmed
In LimsPulse · Calibration Management
Keep every Copper corrosion bath in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.