Force/Pressure Applied Sensor?

[JZerb]

I’m looking for, and I can’t seem to find, a sensor or transducer that will give me a reading of pressure applied to an object. Squeezing or clamped pressure is what I’m trying to achieve. It’s going into an ML1400 and it could be a 4-20ma signal or a 10-30v signal, either could be worked with.

[RDS]

Try searching for a load cell. Many types available.

[James Mcquade]

as RDS said, look at load cells.

most all load cells are mv/volt excitation, so you will need an amplifier.
you can buy them 0-10v or 4-20ma.

CAUTION - this is from experience.

what is your application?
I say that because load cells are subject to destruction from load shock.
applying a load to a load cell is one thing, applying a sudden grip load is another story.

sudden application of a force to the load cell will result in an impact load of 6-10 times what the load sees after it settles (2-3 seconds later).

for example, picking up a 25 lb weight using an air cylinder even 1 inch at what I considered a slow rate caused the load cell to fail after a month.

we had to use a 250 lb load cell. we soon learned to increase our load cell capacity by a factor of 6 to 10.

james

[keithkyll]

If you want to put a device inside the stack, look at Compression types.
If it's driven by an air cylinder, you could look at the stress at the cylinder mounts, and use a Tension/Compression type with bolt studs.

[alive15]

You can check out this load cell and amplifier; you can tie this to your PLC to get the 4-20 mA reading.

[JZerb]

Originally Posted by James Mcquade

as RDS said, look at load cells.

most all load cells are mv/volt excitation, so you will need an amplifier.
you can buy them 0-10v or 4-20ma.

CAUTION - this is from experience.

what is your application?
I say that because load cells are subject to destruction from load shock.
applying a load to a load cell is one thing, applying a sudden grip load is another story.

sudden application of a force to the load cell will result in an impact load of 6-10 times what the load sees after it settles (2-3 seconds later).

for example, picking up a 25 lb weight using an air cylinder even 1 inch at what I considered a slow rate caused the load cell to fail after a month.

we had to use a 250 lb load cell. we soon learned to increase our load cell capacity by a factor of 6 to 10.

james

The force applied won’t be sudden. The load is driven by a screw and I want to make a safety provision in the machine to make sure that the force applied to the object that is being clamped stays “clamped” during operation. If the clamp were to loosen up during machine use I want to set something up in the logic that will stop the machine so that things don’t go flying all over. I’ll look into what was suggested above tonight, thanks all

[AustralIan]

Load cell sounds like the thing. You can make or buy a housing for them that stops them from seeing any greater force than they can withstand.

[shooter]

a simple spring with a contact is sufficient, or have a look at arduino tactile sensor