A small trick that allows Seek thermal to perform better in hot days - Page 1
Forum section: electronics / general

author: Ackley Connor
author_rank: Newbie
timestamp: May 19, 2019, 12:43:05 pm
content: Hello, that's my first topic in this forum, after I received my Seek Compact pro several days ago.Inspired by frenky's idea and my own observation, I found that cooling down the fuselage of Seek really helps, especially in hot summer days. The two following pictures took with or without cooling down under the vent of the air conditioner:So I considered how to cool it down by simplest method, and here is my solution to utilize the latent heat of vaporization:I use a small piece of aluminum heat sink as the scaffold and cover it by bandage, the material chosen by me for its porous structure to vaporize water and the easy accessibility in daily life. At first I only come up the idea with bandage until I realized integrating a piece of heat sink can strengthen its shape and expand the contact vaporization surface.The result is out of my expectation that the simple structure can bring down the temperature for almost 8 ℃, and thus the image captured by Seek's sensor becomes way more cleaner.Although the temperature reading is reversely higher than normal due to I cool down the sensor externally, the improvement of image quality already makes my very happy.Furthermore, I have a thought of using other more volatile solvent like acetone with a compact designed cooling system without eroding Seek's case or causing fire

author: Ackley Connor
author_rank: Newbie
timestamp: May 19, 2019, 12:44:35 pm
content: here is the simple cooling device

author: Ackley Connor
author_rank: Newbie
timestamp: May 19, 2019, 12:47:09 pm
content: And I'm also trying to make a small cooling device with a 2*2cm semiconductor cooling core. If I find any thing interesting I will show you at that time.

author: Ackley Connor
author_rank: Newbie
timestamp: May 19, 2019, 12:55:57 pm
content: the temperature of the saturated bandage with heat sink, and the surrounding temperature:

author: Spirit532
author_rank: Frequent Contributor
timestamp: May 19, 2019, 05:37:27 pm
content: Peltier cooling the seek has been done already on this forum, and it works very well if you can avoid condensation.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 19, 2019, 09:17:08 pm
content: Welcome..and congrats with your Seek Pro. and look forward to seeing more result of your DIY cooling solution.(numerous tear-apart videos on yt if you lack info on how Seek have seed their internal heat dissipation-pad to aluhousing)If you havent notice, in regards to your Seek pro.. please have in mind you have a so-call easter egg. feature in Seeks App.Press the "version" field under about numerous times, and it will open up an easter egg with some advanced features.to fx get live framerate etc. Im on iOS so this feature is not 1 to 1 hence users on Android.

author: IwuzBornanerd
author_rank: Frequent Contributor
timestamp: May 20, 2019, 12:04:50 am
content: I believe that all you are doing when you cool the camera down is simply finding the camera temperature at which the non-uniformity correction (NUC) factors stored on the camera were created. This notion is all the more likely if it is true that, as @frenky said [it might be] that it got worse again as he went colder than 15*C (seehttps://www.eevblog.com/forum/thermal-imaging/seek-thermal-hardware-modification-to-improve-image-quality/msg946689/#msg946689).Most of the garbage in the image would then be due to the adjustments in individual pixel bias that the camera does as its temperature changes. Whenever it changes the pixel bias a notch it causes about a 5% change in the correction factor for that pixel. The effect on the image is pretty bad only a few degrees Fahrenheit off from the temperature at which the NUC was done. You can see this effect in the difference between the 7th & 8th images I posted here:https://www.eevblog.com/forum/thermal-imaging/latest-seek-compact-(non-pro)-has-significantly-reduced-noise/msg1312544/#msg1312544. The right-hand half of the images are from the new, cleaner Seek & the 7th image has correction for the bias changes while the 8th image does not. I have my pixel averaging on there also, so it is comparable to what you would see in the Seek app. The 2nd & 3rd images in reply #7 on that page show you what it looks like with the averaging off and bias correction on vs off. The averaging makes it more "splotchy" like you see with the app.If their app would allow a user-initiated NUC you would not "need" the cooling, IMO.

author: Spirit532
author_rank: Frequent Contributor
timestamp: May 20, 2019, 12:23:38 am
content: Quote from: IwuzBornanerd on May 20, 2019, 12:04:50 amThis is incorrect. Cooling helps reduce sensitivity by means of faster heat dissipation through the legs of the pixels, as well as reducing thermal(ironically) noise.Otherwise there wouldn't be a need for cooled cameras in the first place. You can use an InSb, MCT, SLS, or other detector at room temperature - but good luck seeing anything colder than the sun.

author: IwuzBornanerd
author_rank: Frequent Contributor
timestamp: May 20, 2019, 06:46:38 am
content: Quote from: Spirit532 on May 20, 2019, 12:23:38 amI'm sorry I should have been more clear that I was speaking specifically of the Seek cameras and in regard to my experience with their behavior. I certainly was not referring to cooled cameras and I'm not trying to argue that cooling won't reduce noise. I probably should have said that I think the majority of the improvementin this caseis because the NUC was done with a cooler camera.Looking closer at my samples vs. the op's sample, however I see that I don't get images that clean even with a fresh NUC (about that good at 6*C span, running the Pro right now).I'll still be surprised, though, if it would be that clean if the NUC was done at a temperature more than a few degrees off from the cooled temperature. I guess I need to try that someday.Edited to add a comparison photo showing an image from my Pro with fresh NUC at 79*F and 6*C temperature span along with the same on a 3*C span with the o.p.'s 3*C span image in-between. I think the 6*C span looks a little cleaner than the o.p.'s cooled image so perhaps it's not a 2:1 difference, but I think a fresh NUC is good enough for me. These are as good as they get on the Seeks but sadly the image degrades a bit with the very next shutter frame so it's hard to get the absolute best image.If one is stuck with the Seek app, though, one cannot get a fresh NUC...

author: Spirit532
author_rank: Frequent Contributor
timestamp: May 20, 2019, 08:25:18 am
content: Cooling the sensor to -10 to -100C will definitely improve performance, though one thing I'm not sure of is how the on-die reference temperature sensor will take being chilled way beyond specification.I can almost guarantee that the noise will be all but gone at ~-100C,ifit works.

author: Ackley Connor
author_rank: Newbie
timestamp: May 21, 2019, 11:52:44 am
content: Sorry I have seen your topic before whereas didn't click it because I thought you're talking about the noise soundIt's inspiring to find the huge difference between these two "generations" of seek camera. But as I novice I am concerned about whether I can open it safely. So dose anyone have ideas to verify the versions of two different seek via serial code? Or the tips to open it up intact. By the way I bought it from a bargain seller and have no idea of its version.

author: Ackley Connor
author_rank: Newbie
timestamp: May 21, 2019, 12:02:34 pm
content: here I have a new cooling chip that can create almost 58 Celsius difference in temperature. I gonna test it out another day with a pwm controller, to replicate frenky's experiment.Though I regard cooling it down to a extra low temperature as a intriguing idea, I also have some doubt that will the huge temperature difference tear the moveable part in seek, or the integrity of lens? Will cooling it down gradually and with dessicators be safer? I do have these preparations and hope it works.

author: Ackley Connor
author_rank: Newbie
timestamp: May 21, 2019, 12:28:58 pm
content: a lot of thanks to your work and as far as I understand, have you or other guys figured out the approximate temperature of factory NUC? I even have a thought that - isn't seek manufactured in Santa Barbara? 😂 Looks like nothing mentioned in seek's homepage about their best operation temperature.

author: Ackley Connor
author_rank: Newbie
timestamp: May 21, 2019, 03:18:55 pm
content: I comeback so soon! I buried my seek in a box of dessicator and managed to freeze it below 0 Celsius. it's true that the image get worse - like frenky did. and in this picture there is an ominous stain at the bottom - I assume that's was dew though I tried to dessicate it. I cut down power and gradually up the temperature, soon the best quality achieved at about 20 Celsius.Be advised, the len is very fragile and I regretted to directly put it in silicon desscicators for a tiny scratch I found afterwards.

author: Ackley Connor
author_rank: Newbie
timestamp: May 21, 2019, 03:26:26 pm
content: maybe a good thing is that I can carried it outdoors with a small battery and power controlled 2*2cm cooling chip. No more necessary to cooling it down excessively, save much effort for the heat preservation as well as huge power consumption.I guess I have a neat temperature control design, I will try to post it a few days later.

author: Spirit532
author_rank: Frequent Contributor
timestamp: May 21, 2019, 06:11:15 pm
content: The issue might be with the way they sense the temperature.As I've said, the sensor calibration might go sour if it can't determine/interpolate the right temperature.

author: IwuzBornanerd
author_rank: Frequent Contributor
timestamp: May 22, 2019, 01:03:20 am
content: Quote from: Ackley Connor on May 21, 2019, 11:52:44 amYou have a Seek Compact Pro and I don't know if any of the Pro units were high noise. My thread on the new vs. old was comparing the newer NON-pro units with the early units, specifically one I bought in 2015 vs. the 2 I bought in January of 2017. Myguessis that whatever change they made to make the Pro quieter they also implemented in the NON-Pro units at about the same time, because the image quality from the new NON-Pro units is the same as that of the Pro as far as I can tell.The part number and revision level marked on the pcb is the same in the 2015 & 2017 units I have and the Seek app reports the same software & hardware revision levels for both, but some of the data stored on the cameras is different, such as the extended curve in frame 9. I have tried measuring resistor values & found no difference there either so I have not determined what exactly is different that makes the newer ones better.The lid is spot-glued onto the base of the camera in a few places on each side & the easiest way I found to pop them open is to take a thin strip of metal (I used a piece of a "door" off a 3.5" floppy disk) & insert it into the crack between the lid & base & pry on it at various places around the perimeter. Beware that there are exposed bond wires on the sensor chip and the "tunnel" in the lid is very close to those wires.

author: ir.ukrm
author_rank: Contributor
timestamp: August 06, 2019, 06:48:27 am
content: There is a problem with Seek Thermal PRO, the temperature is not registered correctly, about 18 degrees lower than the actual one, what could be the problem, and is it possible to fix this. Emissivity 0.96.Фото 06.08.2019, 9 37 25.jpg(66.56 kB. 640x480 - viewed 264 times.)Фото 06.08.2019, 9 37 25.jpg(66.56 kB. 640x480 - viewed 264 times.)

author: Valon
author_rank: Newbie
timestamp: August 08, 2019, 12:39:09 am
content: Hi ir.ukrm, i got today my thermal seek compact and the temperature readings are 15 to 20 degrees C higher. I am a beginner and I am sorry I am not able to answer your question, but whne I saw you have a similar problem I just wanted to add mine so maybe someone more experienced can answer.