Recommendations for a project that needs multiple weight sensors

Hi,

I am working on a project that needs multiple weight sensors place under a flat surface, with video projected on top. I am putting different objects on each sensor, and the idea is that when the object is being removed, play a video.
I have been looking at different load cell sensors, which a certain angle of the surface has to be tilted; and also pressure sensors, where they are not recommended for accuracy.

Hence, I would like to ask if there are any recommendations for this scenario or if I should try and use other sensors please?

Cheers,
Karen

cklkaren:
Hi,

I am working on a project that needs multiple weight sensors place under a flat surface, with video projected on top. I am putting different objects on each sensor, and the idea is that when the object is being removed, play a video.
I have been looking at different load cell sensors, which a certain angle of the surface has to be tilted; and also pressure sensors, where they are not recommended for accuracy.

Hence, I would like to ask if there are any recommendations for this scenario or if I should try and use other sensors please?

Cheers,
Karen

Actually, lets expand your description a bit:
Are you looking for a CHANGE in weight as something is added or removed, or just the fact that some weight is placed or removed. In other words, a variable value or just an off/on.

Is your surface a solid surface, such as a sheet of plywood or metal. If so, any weight will be distributed over the entire surface area. If your surface is flexible, how does that work for your project?

Will your surface be supported only by the sensors? Are their limits/stops for the surface so damage is not done to the sensors? How many ways can the surface be tilted?

Paul

Force sensitive resistors can't be used for accurate measurements, but certainly can report a small change in pressure, or removal of a supported object. Seems perfect for detecting presence of objects on a surface.

Paul_KD7HB:
Actually, lets expand your description a bit:
Are you looking for a CHANGE in weight as something is added or removed, or just the fact that some weight is placed or removed. In other words, a variable value or just an off/on.

Is your surface a solid surface, such as a sheet of plywood or metal. If so, any weight will be distributed over the entire surface area. If your surface is flexible, how does that work for your project?

Will your surface be supported only by the sensors? Are their limits/stops for the surface so damage is not done to the sensors? How many ways can the surface be tilted?

Paul

Hi Paul,

Thank you very much for your reply.
Yes, I am only looking for a change in weight if something has been removed, like you said, a variable value or just an on/off.
In terms of the surface - yes it will be a sheet of plywood or metal, with the weight distributed over the entire surface area.

The surface can be supported on its own, and since the table cannot be tilted, I am now thinking maybe load cell sensors are not a good option. I am currently considering NFC or RFID tags. However, the objects I am placing on top of the sensors are transparent. So I am also considering other options if possible :slight_smile:

Cheers,
Karen

jremington:
Force sensitive resistors can't be used for accurate measurements, but certainly can report a small change in pressure, or removal of a supported object. Seems perfect for detecting presence of objects on a surface.

Hi @jremington,

Thanks so much for your suggestion. However, I have read about the unstable inaccuracy. This is a project that is running for 2 nights for more than 10 hours and would you still recommend the use of it?

Cheers,
Karen

Without more details about the hardware and conditions it is impossible to say.
FSRs are cheap, so try one and see.