New MPC Test Procedure
Technical Bulletin
New Membrane Patch Colorimetry Test Procedure
TESTOIL is modifying its Membrane Patch Colorimetry (MPC) test procedure to a newly proposed ASTM standard.
Test Revisions
The proposed ASTM standard for the Membrane Patch Colorimetry test requires a sample to be heated for a period of 24 hours at the lab to allow any insoluble materials to return into the solution. This effectively "resets" the sample to account for inconsistencies in shipping times or storage time prior to shipping. The sample is then held at room temperature for 72 hours before being analyzed.
Other Improvements
Along with this change, we will also be replacing our spectrophotometer with an improved instrument. These two changes are expected to improve data quality, but future results will be lower than historic data. Our alarm limits will be adjusted accordingly. The new critical limit will be 33 dE and the marginal limit will be 23 dE.
