Overview
The design of the PTC1™ Part No. 990-197) is very simple in order to keep cost down, since most users will require many cells for testing. The flat sample under test is clamped between a glass tube with an O-ring seal and the PTFE base. The tube is partly filled (20-50 mL) with the test electrolyte and sealed with a rubber stopper. A reference electrode (possibly Saturated Calomel) and a graphite rod counter electrode are mounted through the stopper.
For users concerned about graphite particles from the counter electrode contaminating the solution, then use the Counter Electrode Bridge Tube (990-194) with a Platinum wire counter electrode. The platinum counter electrode is isolated from the sample electrolyte by a glass frit.
Recommended Uses
Paints and Coatings
The PTC1™ is perfect for testing of painted metal specimens using Electrochemical Impedance Spectroscopy. The exposed area of almost 15 cm2 is sufficiently large to incorporate a statistically significant number of defects in the coating. The large area is also a positive attribute from the data acquisition standpoint, since high impedance samples such as coatings are characterized by low current densities.
The PTC1™’s low cost becomes important for this application since high sample throughput and long-term exposure may require many cells setup at any given time. This type of testing is made most cost effective when combined with a multiplexer.
Corrosion Testing
The PTC1™ can also serve as a low cost flat cell for corrosion testing. It does not possess the larger volume necessary for longer tests or faster corroding materials, but for running a quick open circuit and polarization resistance test it can serve quite well. It will also work well for very low corrosion rate measurements since the exposed area can be large. For most corrosion testing of flat specimens, however, consider a ParaCell™ or, if crevice corrosion is a major problem, a FlexCell™.
METAL SPECIMEN
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Disk Shape |
Diameter at least 70 mm |
Square Shape |
at least 60 mm on a side |
Thickness |
1- 10 mm |
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VESSEL DIMENSIONS
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Volume |
20 ml ( minimum volume ); 50 ml ( maximum volume ) |
Inner Diameter |
30 mm |
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TEMPERATURE RANGE
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Operating |
-25ºC to 140ºC |
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CHEMICAL COMPATIBILITY
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Materials |
Pyrex™, PTFE, Viton™, silicone rubber |
Replacement O-Rings for PTC1
Replacement O-Rings can be purchased from Kontes. The Part Number is 758292-0223. The dimensions of the O-Ring are: i.d. 40.87 mm, cross-section 3.53 mm.