4Pcs Thin Film Pressure Sensor 20g-2Kg High Sensitivity Force Sensitive Resistor Force Sensor Pressure Sensors for Arduino DIY Industrial Precise Measurement Control

My daughter used them for school engineering project

Great package, good sensitivity and range.

As a DIY enthusiast dabbling in Arduino-based projects, I was on the hunt for a reliable and sensitive pressure sensor for another home automation project. The RP-C Thin Film Pressure Sensor caught my eye with its high sensitivity and ultra-thin design, perfect for integrating into compact designs and shrinkifying my projects! The responsiveness is crazy quick!! The durability claim is very interesting, they claim that it's engineered to withstand over a million uses with less than 3% variance in resistance; only time will tell if this holds up. It's sooooo thin that I am interested to see how that plays out! It also is rated to handle some pretty extreme temperatures from -40°C to +85°C, so I am going to use it in a trigger device in some outdoor applications in Texas over the summer! If it can handle that, then it is safe to say it can handle almost anything! LOL! All-in-all, these are super thin and make some pretty bold claims! Great value and I'll update my review if anything changes.

I was working on a project to monitor the amount of liquid left in a glass or jar. I thought that using a force sensitive resistor like these from MakerHawk would be a good way to go. They look easy to use and control and the 2kg weight range is ideal for my purposes. After a few experiments I quickly realized that these devices weren’t very precise. They work by being sandwiched between two flat plates with a weight or other force applied across them. The electrical resistance decreases as the weight increases. The Amazon listing shows some very compelling plots demonstrating this working. In practice, I found that even a slight change in the angle between the two plates (e.g. if the load was moved a bit off-center) or if the plates weren’t perfectly flat, made a big difference in the measurement. I had to disband this idea completely and start looking at more complicated load-cells to weigh the glass. I think these FSR devices have utility – perhaps to detect whether a glass is present or not, but to make meaningful weight measurements looked to be a challenge.