First, I think it's important to point out that only the following load cells can be plugged directly into the analog input on a PhidgetInterfaceKit or an SBC:3121_0 - FC22 Compression Load Cell (0-25 lbs)3122_0 - FC22 Compression Load Cell (0-50 lbs)3123_0 - FC22 Compression Load Cell (0-100 lbs)
The rest of them need to be connected to the PhidgetBridge 4-Input
, and then to the USB port of a computer or SBC.
1. We do not have any boards with more than 8 analog inputs.
2. We are no longer buying new stock of the FC22 series load cells due to low demand. You may be able to contact the manufacturer, Measurement Specialties for more stock.
3. The advantage of micro load cells is that their structural design allows you to measure force in only a single direction (shear force, but not compression or torsional force). As for accuracy, you can compare the specifications listed on the data sheets for the individual cells. Each one is different, but a large part of the resolution of the measurements depends on the measuring range of the load cell. Smaller ranges have higher resolutions.
As for waterproofing, neither of these types of sensors have official specifications, and we haven't tested them personally in wet applications. The micro load cells should be resistant to drips and splashes thanks to the silicone coating, but obviously the Phidget boards are not.
As for installation, the compression cell requires a bit of soldering since it needs to connect to a Phidget sensor cable. The load cells that connect to the PhidgetBridge are simply wired into the screw terminals.
4. You should be able to run 8 load cells directly from the Phidget board they're connected to; they use a very small current, which is why they usually need to be amplified.