Thermally & Electrically Isolated Ø1" (Ø25 mm) Posts
- Enhanced Thermal and Electrical Isolation of Components
- G10/FR4 Fiberglass Posts and Glass-Mica Ceramic Pedestal Post Available
Ø1" Ceramic Pedestal Post,
1/4" (M6) Counterbore
Ø1" Pillar Post
Ø1" Mirror Mount
Ø1" Fiberglass Post,
Ø25.0 mm Fiberglass Post,
|Ø1" (Ø25 mm) Post Material Comparison|
|Material||G10/FR4 Fiberglass||Glass-Mica Ceramic||303 Stainless Steel|
|Thermal Conductivity||0.29 W/m•K||0.87 W/m•K||16.2 W/m•K|
|Electrical Resistivity||1.00 x 1011 Ω•cm||1.00 x 1010 Ω•cm||7.2 x 10-7 Ω•cm|
- Insulating Ø1" (Ø25.0 mm) Pillar and Pedestal Posts
- Ultra-Low Thermal Conductivity and Ultra-High Electrical Resistivity
Thorlabs' Ø1" (Ø25.0 mm) fiberglass pillar posts and ceramic pedestal posts are designed to provide high levels of thermal and electrical isolation. The fiberglass posts feature threaded steel inserts and torque holes for tightening leverage, while the the pedestal post features a bottom-located counterbore for attachment to Ø1" (25.0 mm) pillar posts.
In order to demonstrate the superior thermal isolation of our RS04PC(/M) Ø1" (Ø25 mm) ceramic pedestal posts, we performed an experiment using the apparatus shown below left. A breadboard was placed on top of a standard portable electric burner. Two RS2 posts were tested. One was attached to our standard stainless steel RS05P pedestal post, while the second was attached to our ceramic RS05PC pedestal post. A CF125 clamping fork was used to secure each pedestal base. In the experimental setup image below, the stainless steel base is to the left, while the insulating ceramic base is to the right.
The electric burner was turned on to its highest setting, and the breadboard and posts were allowed to heat, while the temperatures of the two RS2 posts were recorded. The results are shown in the graph below right; after 30 minutes, the post with the insulating ceramic base was significantly cooler than the post with the standard stainless steel base.
IR Camera Demonstration
The test was then repeated, using an IR camera to view the temperature change of the system. During this test, the front surfaces of the posts facing the camera were covered with tape to limit specular reflection and to get an accurate temperature measurement. Therefore, only temperature readings along the front of the posts (where the tape is present) are valid. The crosshairs shown in each image represent the warmest portion in the frame that the camera detects. The test setup, with the IR camera, is shown to the right. The images below, taken every 2 minutes over 20 minutes, show how the temperature across the posts varies with time, and how the stainless steel post mounted using the ceramic pedestal post remains much cooler than that with the stainless steel pedestal. Please note that the the color scale changes between images, and the maximum temperature that can be recorded by the IR camera is 170 °C.
Start of Test
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Comparison of thermal conduction in stainless steel and fiberglass pillar posts.
- Ø1" (Ø25.0 mm) Pillar Posts Made from G10/FR4 Fiberglass
- Low Thermal Conductivity: 0.29 W/m•K
- High Electrical Resistivity: 1.00 x 1011 Ω•cm
- Max Operating Temperature: 70 °C
- 1/4"-20 (M6 x 1.0) Threaded Inserts in Both Ends
- Torque Hole for 1/8" (3 mm) Balldriver Provides Extra Leverage During Tightening
- Max Torque: 75 lb-in (8.4 N•m)
Thorlabs' Ø1" (Ø25.0 mm) fiberglass posts provide thermal and electrical isolation between the mounted device(s) and the breadboard surface. Each post end features threaded steel inserts and a machined dot on top of each metric post denotes a metric threaded insert. The G10/FR4 fiberglass construction features excellent insulation compared to stainless steel, as detailed in the table above. These posts have the same profile as our Ø1" (Ø25.0 mm) stainless steel pillar posts (Item #s RS1, RS2, RS25/M, and RS50/M).
The plot to the right depicts the measured temperatures of a heated breadboard and the tops of four attached Ø1" posts, including stainless steel and fiberglass variants. The data illustrates the increased thermal insulation of our G10/FR4 fiberglass pillar posts compared to stainless steel posts.
Click to Enlarge
A ring around the counterbore denotes the RS05PC/M as a metric item.
- Ø1" (Ø25.0 mm) Pedestal Posts Made from Glass-Mica Ceramic
- Low Thermal Conductivity: 0.87 W/m•K
- High Electrical Resistivity: 1.00 x 1010 Ω•cm
- Bottom-Located 1/4" (M6) Counterbore for Attaching Our Ø1" (Ø25 mm) Pillar Posts
These Ø1" (Ø25.0 mm) ceramic pedestal posts are designed to provide high levels of thermal and electrical isolation. These are ideal for mounting components that may be sensitive to heat or sources of electrical noise. The glass-mica ceramic material used to manufacture these posts has a similar coefficient of thermal expansion to that of the stainless steel used in our standard Ø1" (Ø25.0 mm) posts but lower thermal conductivity. In addition, the high electrical resistance makes our ceramic posts ideal for mounting sensitive electronic measuring devices, such as position sensing detectors. The table above details the differences between the thermal conductivity and electrical resistivity values for the ceramic used to fabricate these posts compared to our standard posts.
These insulating ceramic posts are 1/2" (12.5 mm) tall and have a pedestal design with the same profile as our Ø1" (Ø25.0 mm) stainless steel pedestal posts. They are designed to be used as a base to our Ø1" (Ø25 mm) pillar post extensions. A 1/4" (M6) counterbore on the bottom of the ceramic post allows a 1/4"-20 (M6) cap screw to pass through the ceramic post and thread into the pillar post; both a cap screw and a washer are included with the RS05PC.
Extensive testing was performed under harsh conditions to demonstrate the isolation properties of the ceramic material. For details, please see the Test Results tab.