Lovibond ICx Operator Instruction Manual
PDF · Manufacturer document
Clear-liquid colour measurement depends on the instrument and on the cell and sample through which the light passes. Fingerprints, residues, bubbles and turbidity can affect transmission and bias readings. Consistency is especially important at low colour levels.[1]
The example is Pt-Co measurement in the Lovibond ICx operating manual. The path length, orientation and baseline requirements below apply to the specified instrument and method, not to all colour instruments or scales.
Confirm the path length first
The ICx manual specifies a Lovibond 100 mm path-length cell for Pt-Co measurement and advises against using another path length for this scale. A cell fitting into the chamber does not establish method suitability.[1]
Keep the same cell and orientation
Use the same cell for the baseline and subsequent sample measurement to reduce cell-to-cell differences. Insert the 100 mm cell with the Lovibond marking facing the operator and gently position it forward and left against the chamber guides.[1]
Handle the frosted sides rather than the clear end windows. Clean a new cell before first use; packaging does not ensure film-free optical surfaces. Follow the manual for damaged or discoloured cells rather than relying on the baseline to compensate.
A baseline is not permanently valid
For sample measurement, the ICx baseline uses the same cell filled with purified water. The manual recommends repeating the baseline before each sample where possible; below 30 Pt-Co, it specifies at least every two hours as a minimum precaution.[1]
This interval is an ICx requirement, not a universal frequency. Measure samples that discolour rapidly on environmental exposure promptly rather than leaving them open. Follow instrument status indications; the manual recommends waiting until the Measurement Optimiser indicator is no longer red before the next measurement.
Investigate distinct interference sources
- Bubbles or particles: interference with transmission is not necessarily increased sample colour.
- Turbidity or crystallisation: establish method suitability; do not filter, heat or otherwise alter a sample and report it unchanged as the original.
- Fingerprints and films: inspect end windows, cell walls and the measurement area.
- Residual water: dry the cleaned cell adequately as instructed to prevent sample dilution.
- Mixing and temperature: uneven mixing and temperature gradients can affect light transmission.
Consult the sample SDS and check cleaner–cell compatibility. Treatments that change sample properties must be addressed in the method and record, not used silently to remove optical interference.
Three checks with different purposes
| Check | Main purpose | ICx distinction |
|---|---|---|
| Purified-water baseline | Establish the reference for sample measurement | The same 100 mm cell as the sample |
| Glass reference filter | Check instrument performance with less sample-handling involvement | Empty-chamber baseline, then the specified filter orientation |
| Pt-Co liquid reference | Check the instrument and cell, cleaning and positioning | 100 mm path length, water baseline, same clean cell and certificate comparison |
Evaluate each reference using the applicable scale and certificate tolerance. Never return used liquid standard to its bottle. A satisfactory filter check does not prove the sample cell or handling procedure is free of problems.[1]
Key points
Keep cell, orientation, path length, baseline and sample state consistent. Investigate these first, then assess maintenance or further performance checks; do not adjust the instrument from one anomalous reading.
References
- [1] Lovibond ICx Operator Instruction Manual, PDF page(s) 18–19、36–41 (file page order). View reference resource