Right thermal camera for multi point, and long duration monitoring (computer) - Page 1
Forum section: electronics / general

author: Hend
author_rank: Newbie
timestamp: June 17, 2025, 11:27:15 pm
content: I'm working on a project where I need to monitor and plot the temperature of multiple small points (~1 mm each) in real time on a computer, and ideally over long durations.The key challenge is that the target points are moving, so the camera/software must be capable of tracking temperature across multiple zones even as the object shifts position.I'm currently considering Seek, Topdon, and InfiRay. From user reviews, InfiRay P2 Pro looks the most promising in terms of image quality and sensitivity. However, I'm not sure if it provides radiometric output and supports multi point zone selection with live temperature tracking on a PC.I found a video using Topdon TC001 software with an InfiRay camera, but it’s unclear how many zones it can track or if it’s stable for long term use. I also came across the ThermoVision_JoeC software, which seems to work well for real time multi zone monitoring with Seek cameras, but I haven’t found any confirmation that it works with InfiRay.If anyone has experience with these setups, especially for multizone, long duration monitoring on PC, I’d really appreciate your insights before making a purchase.Thanks!

author: Fraser
author_rank: Super Contributor
timestamp: June 18, 2025, 08:55:13 am
content: Have you also considered IFOV ?Accurate measurements on a target normally require more than one pixel on the cameras microbolometer to be illuminated. The usual recommendation is at least 4 pixels, preferably 9 being illuminated by the target.I detail the IFOV for the P2 Pro in my review of the camera here:https://www.eevblog.com/forum/thermal-imaging/review-infiray-p2-pro-thermal-camera-dongle-for-android-mobile-phones/The IFOV data is repeated here for your convenience….The IFOV for the P2 Pro camera with its 56 Degree HFOV lens and 256 Horizontal Pixels is 3.81792 mRadAt 10cm the pixel size on target is: 0.38mmAt 15cm the pixel size on target is: 0.57mmAt 20cm the pixel size on target is: 0.76mmAt 30cm the pixel size on target is: 1.14mmAt 60cm the pixel size on target is: 2.29mmAt 90cm the pixel size on target is: 3.43mmAt 120cm the pixel size on target is: 4.58mmIf you are trying to measure the temperature of a 1mm target, you will need to get very close to it due to the large FOV lens that is used. Being so close will limit the area that can be monitored.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: June 18, 2025, 09:16:44 am
content: Just having a think about the requirements to track the 1mm targets….There are cameras that have hottest spot tracking and temperature logging. They usually monitor either the whole thermal scene, or a part of it that is contained in an ROI box. The hottest target in the ROI box is measured. It is sometimes possible to have multiple ROI boxes on the screen and all are monitored for their hottest point and this is logged. You have not mentioned the nature of the target that you are monitoring. If it is monitoring of the moving hot spots on a large SoC IC/multiple SoC IC’s, that may be possible. If it is monitoring the temperature of tiny insects running around a Petri dish (!) that is a much harder challenge as the software has to actively identify and track each target as it moves around the scene using a “breadcrumb trail” analysis. Such target tracking is done in thermal people counters. You would need quite a sophisticated piece of custom software to correctly track multiple random movement targets that are moving around the whole thermal scene, whilst also logging their temperatures accurately.Fraser

author: Hend
author_rank: Newbie
timestamp: June 18, 2025, 02:27:01 pm
content: Thank you for the explanation, that really helps!To clarify my setup:The samples (liquid) are placed inside tubes arranged in a circular pattern, and the entire platform rotates slowly at about 10 RPM. The thermal camera is mounted above, covering a circular area of around 15 cm in diameter (sometimes slightly less). Based on your response, if I place the camera at around 15 cm away, the pixel size will be approximately 0.57 mm. In that case, would you recommend using a higher resolution camera for better accuracy?Also, as the tubes rotate, the samples inside them rotate as well, meaning each sample’s position changes over time.My goal is to track the temperature evolution of each sample in real time throughout the rotation. To achieve this, I’ll need real time access to the temperature data of each pixel, not just a few fixed ROI boxes. Since the samples are in motion, monitoring only 10 fixed zones wouldn’t be sufficient. I’d need access to the full radiometric data for the entire frame to dynamically analyze and track each sample as it moves.

author: Fraser
author_rank: Super Contributor
timestamp: June 18, 2025, 03:15:33 pm
content: Hend,Please clarify something.You are placing samples in something like a medical robot sampler carousel and have stated that the target is only 1mm in size. Unless you are using capillary sample tubes I presume you mean you want a resolution for measurement purposes of 1mm diameter on the surface of the sample tube (which is of far greater diameter). I presume that you are aware that the thermal camera will only be able to measure the fluid surface temperatures and not anything deeper in fluid. When positioning a thermal camera in the centre of a rotating test tube carousel you will also need to consider the angle at which the camera views the sample surface as the sides of the sample tubes are opaque at LWIR and can impinge upon that view unless the fluid is at the very top of each sample tube.You have asked about camera resolution. At the moment I am not clear on the requirements, hence the comments above. Normally fluid motion and thermal swirl is monitored with a camera positioned directly above the sample tube and not a single camera monitoring multiple sample tubes as that does challenge the cameras ability to produce fine detail with a large field of view lens fitted.Maybe a sketch of your apparatus would make matters clearer ?Fraser

author: Vipitis
author_rank: Frequent Contributor
timestamp: June 18, 2025, 08:47:10 pm
content: can you also rotate the camera? Would make the measuring points stable again...

author: Hend
author_rank: Newbie
timestamp: June 19, 2025, 09:12:21 am
content: Thanks Fraser, really appreciate your detailed response.I uploaded a sketch to make things clearer. The setup uses a rotating tube holder (~6 cm) with multiple small tubes, each with a 1 mm opened hole (~3 mm deep). The liquid levels will vary, some low, some near the top... and may drop over time.The thermal camera is placed above, but since the holder rotates in a 15 cm circular path at ~10 RPM, the samples won’t always be centered. We want to track surface temperature changes every 0.5 seconds, ideally at around 1 mm resolution.As you pointed out, the viewing angle matters, since the tube walls are opaque in LWIR. So we’re considering two options:Get a better resolution and FOV camera, orMove the camera to follow the rotating holder.Would love to hear your thoughts

author: Hend
author_rank: Newbie
timestamp: June 19, 2025, 09:23:51 am
content: Thank you Vipitis for the great point!I'm not very experienced with mechanics, but full rotation might get tricky with cables (and unfortunately, I can’t use a wireless camera in this setup). So I’m thinking of linear movement instead, since it’s simpler and avoids cable issues. I'm just not sure if that would keep good alignment with the tubes as they rotate. What do you think?

author: Sorama
author_rank: Frequent Contributor
timestamp: June 19, 2025, 09:54:30 am
content: How are you going to measure low temperature correctly when an IR camera has an accuracy of +/- 2 degrees C at minimum plus some percentage ??Even frequency will be way too low.For this, you need highly specialized fast IR camera’s.Not some toy from Aliexpress.

author: Bill W
author_rank: Super Contributor
timestamp: June 19, 2025, 03:24:43 pm
content: I would be concerned that the camera angle of view might not see 'into' the holes as you want.This all seems more suited to some hardware thermometry, maybe logged locally on the moving parts to avoid some/all cable issues.