C-THERM TCi, Operator'S Manual, Page: 45 / 138

TCi Operator Manual
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A straight end flexible metal putty knife is the recommended tool for applying the thermal grease.
Scrape a very thin uniform layer on the surface of the sensor, just sufficient to fill any pores.
Sweep the putty knife over the sensor surface so that no green is visible. Be cautious to avoid
scratching the sensor’s surface. An excessively thick layer can affect the sensor readings. Try to
be minimal in its application – just enough to provide the necessary seal. (One way to tell if the
layer is too thick is if sample values trend in one direction over many minutes before stabilizing.)
Note: For users unfamiliar with the application of conductive grease as a contact agent,
this can lead to an issue of paste consistency being raised and questions on the impact to
the measurement. How much or how little thermal grease is required for consistent
results? Clients are encouraged to practice using the thermal grease with the Pyrex
reference standard provided with the TCi system prior to commencing sample testing.
Pyrex is optimal in this case as you can actually see the contact occurring at the testing
surface through the material. Results should fall within a better than 5% accuracy of the
expected value for the reference material. (Pyrex = 1.143 W/mK @ 25° Celsius with an
acceptance range of 1.09 to 1.20 W/mK).
Step 2 – Place the sample on the thermal grease.
Step 3 – Perform the test.
Use the general procedure and select the Wakefield Type 120 as the contact agent.
Note: The contact agent correction factors must be entered into the TCi database for
temperatures other than ambient (20-25°C). Values for all other temperatures are above.
Step 4 – Clean the sensor.
Once the test is complete, wipe the sensor with a paper towel or KimWipe to remove most of the
thermal grease.
Place 1 drop of TR-1 Thermal Material Remover on the center of the sensor. Carefully wipe off
the cleaner and any remaining grease after 30 seconds.