Well now… let me just get out my credit card, I need one of those…
1 Like
Do you have a suggestion for the low cost hydrometer to put in each box?
I have like 12 of those boxes.
There are three broad categories of cheap monochrome LCD hygrometers that can be found all over the net. They are all powered by LR44/SR44 batteries which is how you can put them into a single class. I’ve tried to reverse-engineer their components and learned that they are all based on the same design and/or possibly made in the same factory.
Those categories are:
- Round
- Rectangular
- Rectangular with and external wired probe
Then they break down into three more broad categories
- Celsius-only
- Fahrenheit-only
- Switchable by a shunt or solder bridge(much rarer to find)
Here are three that I’ve purchased. Note that the round versions also sometimes can be found if one searches for “Humidor Hygrometer”
https://www.amazon.com/gp/product/B07KBW4W12/
https://www.amazon.com/gp/product/B0885TFLZX/
Now the bad news. All and I mean for ALL of these, you have to resign yourself to the fact that they are disposable. I get maybe 6mo to a year of life out of these garbage devices and accuracy is just OK, not perfect. These are all so shoddily made that I find quite often, they battery outlasts the LCD.
Also, they have a bottom end sensitivity of 10% RH.
I prefer the external probe version. This is primarily because these are all made from very low end LCD’s with a max operating temp of 50c which means if they are inside the box, and the box gets too hot, the LCD will go black. Often it will recover after cool-down but the external probe version eliminates this problem.
If you buy them in bulk, I have seen them as low as $0.50ea on places like Ali Express.
Here’s the largest example I’ve seen on Amazon. What’s maddening is that often the Chinese sellers don’t tell you if it’s C or F or they just ship you what they have even if the description says otherwise. Which is why I prefer Amazon as I tend to return about 10% of the ones I buy. I have probably purchased over 50 of these in the last four years. I have purchased higher quality LED based thermometers for my System Builds but now you’re talking anywhere from $15-$20 but those are built to last and when you’re protecting a $3K system build, it’s justifiable. But I mention it solely because I have tried to find that goldilocks zone between price and quality and unfortunately there is a chasm, you can’t get both.
Incidentally, I use the round ones for my more exotic hydroscopic spools like Lime Green ABS or PETG that I don’t use often and therefore store for extended periods. I leave them in the bag. That’s’ because for those filaments, the indicator cards aren’t enough. I want to know before I go to print if the internal RH is under 10%.
3 Likes
These are great and I highly recommend. I have 2 of the 75L containers with each holding up to 22 rolls and desiccant. A little pricey, but worth it.
5 Likes
Perhaps I missed something. Can you be a little more specific as to “these” like part number and place to purchase for others that might want to look into them or get some?
Thanks
1 Like
Sorry, the link was in the post i was replying to. These are the 75L bins from Home Depot
1 Like
thank you for the follow up
Target also has gasket boxes like the one shown above at usually very good prices.
This is key. If RH is less than 10%, they generally read as 10% or 0%. The struggle is to find ones that accurately read all the way down to 0%.
If CNC kitchen ever does his promised video on desiccants. it will probably cover molecular sieves, which will help keep RH levels very low, in the single digit range. I don’t know why more people don’t talk about molecular sieves. They’re readily available. You can even buy them on amazon.
Well if you find one please let me know. I have been searching for a sensor that will perform below 10% and outside of the really expensive >$600 fluke meters, I haven’t found anything outside of laboratory-class devices. I want to build my own Arduino-based Hygrometer that goes below 10%RH and so far have struck out.
I’ll have to try it out when I get home, but my AirGradient AQ meter has a temp/humidity sensor that’s supposed to have a range of 0%-100%. It’s the Sensirion SHT4x and you can use it with an Arduino.
1 Like
I’m using Zigbee temperature and humidity sensors I’ve found on Aliexpress:
They are not realy low cost, but sometimes they are available for less than 4€ per piece. I want some sensors, which have a display but can also integrated into my smart home.
2 Likes
@Olias There you go. Inexpensive wireless sensor with its own display, and evidence it can read below 10%
I’ve been using these:
which are very easy to deploy and use, with free cloud tracking and graphing, and being LoRa have fantastic range, but @print.in.3d solution is more cost effective.
1 Like
I probably should have explained my ask a little clearer.
Unfortunately, that device above does not meet my criteria. Not even close. I am looking for an actual sensor that I can wire into an Arduino not a box communicating over a cell phone app.
Ideally, what I’d want is an I2C protocol and small enough to attach inside an apparatus and run wires externally. This approach is similar to how I use NTC Thermistors or thermocouples in my system builds, where I attach sensors directly onto critical areas using thermal tape or thermal adhesive.
In the example above, the use of a cell phone app is a showstopper right out of the gate. Combined with the size of the sensor device being huge, it is totally outside the scope of my definition of a sensor.
Here is just one of many industry standard examples. Note the contradiction between range and accuracy range. This is typical of the class of product in the category.
https://www.amazon.com/HiLetgo®-Temperature-Humidity-1-5V-3-6V-Compatible/dp/B00XR7CR1I
Well, in that case, the Sensiron sensor that @RandomKhaos referenced above would be a really good choice:
https://www.mouser.com/datasheet/2/682/Sensirion_Datasheet_SHT4x-2936319.pdf
It has the I2C that you want. I’m fairly sure the SHT45 is state of the art. I don’t think I’ve seen any others that can measure RH to +/-1% before. I’ve seen breakout boards for the others in that series on Aliexpress.
Davis Instruments, which makes and sells fairly expensive weather stations, has relied on the sensiron chips for years and years.
1 Like
No brainer. Use 1 gallon zip lock bags (not the ones with the zipper thingamabob) with the desiccant pack that came with the spool. Why spend all that money for containers when you can buy a box of baggies and use the left over money that you would have spent on the containers to buy more filament? You can stack the spools any way you want and have more room because the containers take up a lot of space.
1 Like
Having done it this way before, I prefer the containers with the nice seal, personally.
The boxes help keep things neat and organized.
Plastic baggies wear out pretty quickly once you open them a few times. Also, baggies are fairly permeable compared to well sealed boxes.
The throw away desiccants that come with the spools have no indication of saturation and cannot be trusted to do anything.
I would suggest, at the very least, buy some desiccants that indicate they can absorb moisture.
4 Likes
I live in the desert where the humidity is normally about 20% and never goes over 35% so for me storing things out in the open isn’t a bug deal. So I just bought a couple of these cheap racks from Amazon that a friend recommended. They fit 4 rolls across on each shelf perfectly.
7 Likes
If you can find them, the Lock n Lock 406-Fluid Ounce Rectangular Container with Handle and Drain Grate, Tall, 50-Cup are really great. I managed to get some for around $20 apiece, which isn’t cheap but I bit the bullet. Lock n Locks have really great seals, and the handle on top makes them easy to throw around but folds down for stacking. Each holds 4 standard 1kg spools or 5 750g spools.
When that got too expensive for the number of spools I have, I switched to the vacuum bags, and I just have some IKEA Billy shelves with glass doors. The depth is perfect and the shelf heights of course can be adjusted. It’s very easy to grab the one spool I need. The rack that Dan203 posted might also work well with bagged spools.