IR Thermometer DESOMIYE NJTY T600. Tear down, current measurements, and adding new battery switch
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- เผยแพร่เมื่อ 26 ต.ค. 2023
- This IR Thermometer NJTY T600, also known as DESOMIYE T600, cost $10 on Amazon.
amazon.com/dp/B0BFBDX44Q
It has 149 reviews at the time of posting this video, majority of them are positive with over 4.5 star average rating. It measures a relatively wide range of temperatures, from -50C to +600C (-58F to +1112F).
One downside in my opinion is high battery consumption in the OFF state. It consumes constant 6.7 µA when "turned OFF." That is why I added an OFF switch for the batteries. - วิทยาศาสตร์และเทคโนโลยี
how accurate is it ??
The one I got was about 5 - 10% accurate. I tested it with boiling water and with a mix of cold water w. ice cubes. In theory that should be 100 and zero Celsius in normal air pressure, respectively. But it showed 92 - 95 for boiling, depending how I pointed the laser, and 2 degrees on the mix of ice with water. IR could bounce off the water surface or off the pot's walls, so these measurements can vary.
Was it really worth the bother? I mean who expects to use some included low quality carbon zinc batteries for long? I assume they are old to begin with and only use them to not let them go to waste, but then I readily switch to using alkaline or low self discharge NiMH, and in the case of the NiMH, then what I wonder, and wish you had mentioned in your video, is what is the minimum voltage this T600 will tolerate, since the nominal voltage of NiMH is only 1.2V and I have often seen in the past with cheap chinese products that run off 2 x AAA or AA, that they tend to not be able to fully drain the cells before they quit working, so in the case of 2 x AAA, if it quits working before this series of 2 drops all the way to 2.0V, it wasted some of the capacity.
Typically what I find with the poorly designed products using too few cells is they start to malfunction around 1.3V per cell, and while that is tolerable with low drain devices that I seldom use, otherwise that is annoying when using NiMH. Instead of throwing switches into things which won't solve that, I am instead considering finding some little 3V solar panels and just epoxy those onto devices, wired direct to the NiMH batteries. Granted, then I have to store the devices where they are exposed to light a good % of the time, so not a perfect solution. I wish more of them used 1 x 18650 cell instead. Even though that seems like a large battery for a device like this, it wouldn't necessarily contribute that much to a larger handle beyond what is comfortable to hold, and they are so ubiquitous in laptops and power tool batteries, that I could harvest some and not care if they have only a fraction of their original capacity remaining, then if I'm ambitious, just throw a USB charge/BMS circuit in with it.
It all seems like a lot of work for what as stated above, only costs about $4 on Aliexpress since I do have ample LSD, AAA NiMH rechargeable batteries.
This mod was intended for infrequent, occasional use of the tester and a safe long-term storage without the need to pull out the batteries or worry about self-dicharge.
Carbon zinc batteries are not necessarily "low quality." They are preferred for low power equipment. For higher Amps you'd need alkaline. Some major brands (Maxell, Panasonic) keep manufacturing carbon zinc as well as alkaline batteries.
In my experience, carbon zinc batteries don't leak as often and as badly as alkaline if forgotten and left for a longer time in remotes, etc. Rechargeable NiMH or lithium usually don't leak at all, when compared to alkaline.
In this case, AAA NiMH rechargeables would work but they cost extra and self-discharge over time if you forget to keep recharging.
@@tektech1065 Nope, carbon zinc are low quality. They are cheaper to make and have less capacity, are only included for those two reasons. No "good" equipment includes carbon zinc instead of alkaline or rechargeables but if rechargeables then generally integrate a charging circuit.
There is no harm posed by storing this with NiMH batteries which are so rare to leak that it is extremely uncommon from major brand cells. However I do recognize the problem with a device that has parasitic draw when it shouldn't in the most off state the user can set without removing the batteries. It is senseless that they would design it like that, merely to avoid a 2nd switch to latch on the power when the trigger or another button was pressed.
Apples and oranges.