DeFelsko PosiTector SST
F.A.Q.
Why is salt contamination measurement important?
The presence of soluble salts has been shown to have a significant negative effect on coating performance and leads to premature coating failure. Salts remaining beneath a protective coating create an osmotic force that draws water from the atmosphere through the paint layer. The pressure created by this water underneath the coating overcomes the adhesive bond between the coating and substrate, resulting in corrosion, osmotic blistering and eventual coating failure. It is therefore critical to ensure that a substrate is free from soluble salt contamination before painting.
What is measured with the DeFelsko PosiTector SST?
The DeFelsko PosiTector SST includes a certified and traceable conductivity probe specifically designed for ISO 8502-6,9. Included with each probe is a Long Form Certificate of Calibration. The following parameters are measured by the DeFelsko PosiTector SST:
- Conductivity (μS/cm)
- Sampling Temperature (C° or F°) normalized to 25°C
- Test duration
Using the measured conductivity value and the sample test volume (set within the gage menu), the surface density of the salts (mg/m2 or μg/cm2) is automatically calculated in accordance with ISO 8502-9, saving the gage operator time and eliminating the chance of a calculation error.
What are some typical applications?
The DeFelsko PosiTector SST is ideal for:
- Testing substrates for the presence of soluble salts in accordance with ISO 8502-6,9 (the Bresle Method)
- Testing blast media in accordance with ASTM 4940 and ISO 11127-6 (determination of water-soluble contaminates in abrasives by conductivity measurement)
- Testing the conductivity of water within the range of 0-500 μS/cm
What information does the DeFelsko PosiTector SST save in its memory for each test?.
- Date and time of test
- Test duration (the total time of contact between the solvent and substrate)
- Background sample temperature (°C or °F)
- Final sample temperature (°C or °F)
- Increase in conductivity between background and final sample (μS/cm)
- Calculated surface density of soluble salts (mg NaCl/m2, mg CL/m2, μg NaCl/cm2, or μg Cl/cm2)
