flir boson  reading body temp at 160chttps://www.eevblog.com/forum/Smileys/defau - Page 1
Forum section: electronics / general

author: tommyd
author_rank: Newbie
timestamp: July 26, 2021, 08:48:43 pm
content: Hi allCan anyone shed a bit of light or point me in the right directionBought a used flir boson 640 bit bashed (probably drone crash) attached it to a rhp interface pic is ok but when I look at the files in thermal studio the body temps are coming in at 160c pic attachedAny help greatly appreciatedCheersTommy

author: Fraser
author_rank: Super Contributor
timestamp: July 26, 2021, 09:13:16 pm
content: Sounds like an issue with the ambient temperature sensor circuit. This can cause a huge offset in the measurements. If an FFC flag is in use the ambient/chassis temperature measurement error will be transferred to the FFC calibration, so causing the offset in readings. The ambient temperature sensor can be as simple as a biased diode feeding an ADC input or it can be more complex, such as a self contained temperature sensor with I2C output. I do not know the type of environmental temperature sensor used in the Boson design but it is likely known from information on the internet.

author: tommyd
author_rank: Newbie
timestamp: July 26, 2021, 09:18:01 pm
content: thanks for the reply is there any way to fix it?

author: tommyd
author_rank: Newbie
timestamp: July 26, 2021, 09:22:16 pm
content: think you may be right the suplimental ffc when activated has an overlay image on it is there anyone who can do the lens calibration

author: Fraser
author_rank: Super Contributor
timestamp: July 26, 2021, 09:30:14 pm
content: This thread may be of interest……https://www.eevblog.com/forum/thermal-imaging/flir-boson-32060hz-teardown/The temperature sensor is likely to be in contact with the metal chassis of the Boson or it could be adjacent to the microbolometer in order to provide an accurate temperature for the FFC flag. In the Lepton core a thermistor is used and an intermittent connection of the thermistor to the monitoring circuit causes measurement errors. It would be worth checking for a thermistor on the microbolomter PCBA and then testing the continuity of it to the PCB traces and also to the monitoring circuit it connects to.Not sure what you mean about an overlay image on the FFC. If any latent image appears after the FFC event, it is likely that the FFC flag is not deploying correctly and is stuck in its housing. This causes the camera to see a thermal scene whilst it is trying to configure a flat field and a ghost image is introduced to the following thermal scenes.

author: tommyd
author_rank: Newbie
timestamp: July 26, 2021, 09:34:22 pm
content: cheers for the info well out of my depth with this 1 lol

author: Fraser
author_rank: Super Contributor
timestamp: July 26, 2021, 09:35:21 pm
content: These cores are not easy to work on due to their small size. Be warned that they are easily damagedFraser

author: Fraser
author_rank: Super Contributor
timestamp: July 26, 2021, 11:23:07 pm
content: I just had a thought. Are you certain that your Boson was configured for temperature measurement ? These cores are to be found in CCTV camera applications that do not need the temperature measurement capability so it is not calibrated. There have been many such Boson camera cores on eBay recently. I have not see a camera that is not configured for measurement giving an incorrect temperature rather than just a RAW ADC “Counts”, but I have not worked on a Boson so it may behave differently. If the core is not intended for temperature measurement it will still work fine as an imaging core and the fact that it is providing decent thermal images suggests to me that the NUC/FFC and auto ranging is working fineFraser

author: tommyd
author_rank: Newbie
timestamp: July 27, 2021, 07:22:09 am
content: hi Fraser,Thanks again for the detailed info its much appreciated, think you may be right as I contacted flir with serial numbers and they said its not possible to calibrate the boson.it is being refundedcheers againTommy