DRY&DRY DRY&DRY Premium Humidity Indicator Cards (12 Cards) - 10-60% 6 Spot(Reusable)

Etwas schlecht zu erkennen der Farbwechsel.

I have a host of 3D filament spools and like to store them all in dry storage boxes, some are used infrequently and I'll store unopened spools as well. I bought the cheap $2 humidity sensors but they won't register below 20% and can't be used for really dry environments. These moisture indicating strips are cheaper and more accurate. They are really designed for dry storage measurements. The only downside is they are hard to read and it takes some "practice" to translate the lavender color to moisture value. I initially used a lab grade sensor as a reference and added it to some boxes with a strip to help me understand the color shift. I'm used to seeing the mostly blue dots and can pretty easily tell when the desiccant needs to be recharged. These are much better at monitoring dry storage than the cheapo humidity gages and I highly recommend.

I understood this product to be able to change colour back multiple times. However when I removed it from its packaging all dots turned pink and never returned back to blue again.

the first oreder 'got lost' but i received a credit and ordered again...but the price had gone up! the spots eem to react to the humidity quite well, but the colour change is not terribly clear, quite suntle really.

This were not that expensive way to test humidity on my 3d filament spools. I have them inside the automatic feeder, and on clear bags with my filaments. I have used these types of testers when working as a quality inspector, to make sure the packaging was not affected and still protected the product from humidity. However, these strips, are not very strong on identifying the level of humidity, since the color is hard to distinguish if it is one or the other. So it is difficult to read if they are working fine or not.