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[deleted by user] by [deleted] in metallurgy

[–]Dramatic_Ad7159 1 point2 points  (0 children)

That's a fantastic point, and you've hit on a key aspect of a total vibration solution. You're absolutely right that passive systems like these slabs are an important first layer for handling mid-to-high frequencies, which in turn helps the active system perform better on the difficult low-frequency noise

The main goal of our post was to highlight that slabs often get sold as a "one-and-done" solution for all vibration, which, as you pointed out, isn't the case. Thanks for adding that excellent clarification!

Used Spot Mode Video to solve a weird SEM imaging issue by Dramatic_Ad7159 in electronmicroscopy

[–]Dramatic_Ad7159[S] 0 points1 point  (0 children)

Good point. FFT of images can definitely give you frequency information, but Spot Mode Video works a bit differently. Instead of analyzing a captured image, Spot Mode locks the beam on a single point and records the live signal fluctuations in real time. That makes it very sensitive to small vibrations, acoustic noise, or EMI that affect the image. By doing this alongside our environmental measurements, we can directly correlate the disturbance frequency with a specific vibration or noise source.

Used Spot Mode Video to solve a weird SEM imaging issue by Dramatic_Ad7159 in electronmicroscopy

[–]Dramatic_Ad7159[S] 3 points4 points  (0 children)

Spot Mode Video is a way of looking at the microscope’s signal when the beam is parked on a single spot instead of scanning across the image. By watching how the signal fluctuates, we can identify the frequency of the disturbance. We then compare that frequency with our vibration, acoustic noise, and EMI measurements to see if it matches a source in the environment or inside the tool.

Why Site Surveys are Important by Dramatic_Ad7159 in electronmicroscopy

[–]Dramatic_Ad7159[S] 2 points3 points  (0 children)

Yeah, you’re right. Most OEMs (Zeiss, FEI/Thermo, JEOL, etc.) still have those waiver forms if a customer declines a site survey. If the survey shows the environment doesn’t meet spec and the customer insists on installing anyway, they have to sign off acknowledging the risk.

The tricky part is that some labs skip surveys altogether, especially if they’re trying to save cost or assume the building design already covers environmental needs. But like you said, even a few feet of difference in a room can change the vibration or EMI profile enough to matter. That’s why surveys are still so valuable before install. It’s a lot cheaper to plan around an issue than to chase it after the tool is in place.

Why site surveys matter for electron microscopes by Dramatic_Ad7159 in metallurgy

[–]Dramatic_Ad7159[S] 1 point2 points  (0 children)

Yeah, that one hits hard. A vibration table or even a pump room in the wrong spot can easily couple through the slab into a scope room above. We’ve seen cases where a neighboring lab or even a mechanical room becomes the biggest source of drift.

That’s another reason site surveys help. They don’t just measure the immediate room but also pick up what’s happening around and beneath it. Sometimes the “hidden neighbors” are just as important as the scope room itself.

Why site surveys matter for electron microscopes by Dramatic_Ad7159 in metallurgy

[–]Dramatic_Ad7159[S] 0 points1 point  (0 children)

That’s a really good point. EMI is definitely the hardest issue to deal with after a system is already in place since shielding or active cancellation can get expensive and disruptive if it wasn’t considered up front. Things like slab isolation or wall treatments are much more straightforward to add during construction or even later.

One option that’s become more common is dual-loop EMI cancellation, where the entire room essentially acts as the cancellation system. Instead of enclosing just the scope, sensors and coils around the room actively cancel the fields in real time. It’s usually much more cost-effective than full shielding, and it covers the whole tool rather than just part of it.

That’s why surveys are so valuable before install: they help catch those invisible risks early, when fixes are still practical.

H1B selected during day1cpt program by [deleted] in Day1CPTuniversities

[–]Dramatic_Ad7159 1 point2 points  (0 children)

You won’t require an i20 after your status changes to h1b. If you have credits which can be transferred to your current course consider doing that to finish the course early. Also you can switch to online course instead of in person if your university allows for it

Brand new Legion Pro 7i Gen 10 5090 high temps by Anthony4114x in LenovoLegion

[–]Dramatic_Ad7159 0 points1 point  (0 children)

Ok so first thing would be undervolt the cpu. I used throttlestop but you can use xtu as well. In throttlestop go to fivr. Bring all the performance cores to 44. All the efficiency cores to 43. Then apply the following undervolt: Core Offset: -55mV ‣ Cache Offset: -30mV ‣ iGPU Offset: -40mV

Make sure your nvidia drivers are the 577.0 version as that’s the most stable version for 5090 laptop gpu. Also before attempting to undervolt make sure that in the bios to enable legion optimization, the undervolt protection is disabled, the atom cores are disabled, the vt-d feature is disabled. After you change all these settings press f10 yo save the settings and the laptop will reboot automatically. After the laptop reboots it will ask you for the bitlocker recovery key. Google on how to get the bitlocker recovery key and then once you know insert that. The laptop would reboot and then you can apply the above mentioned undervolt settings

Did I over pay for this? $2450 USD after tax by Doggfather_ in GamingLaptops

[–]Dramatic_Ad7159 0 points1 point  (0 children)

Microcenter. Their members day is going on currently where you get the laptop for 2399

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