# How to design an enclosure around the load cell (Beam type)?

• What class of water resistance do you need? Does it need to withstand things like rain/splashes or does it need to be submerged in water? May 29, 2021 at 19:06
• If you see fluctuations, that indicates that the box is vibrating when the weight is put on it. First, you will need to damp out these vibrations with a viscoelastic silicone sealant (for example). Next, you will need to compute the effect of deformation of the vertical sides of the box on the weight that's measured and correct for that. I'm assuming the box is submerged in water. Alternative designs can be thought up if that's not the case. May 29, 2021 at 22:22
• Does the load cell need to go in the water? Perhaps you could arrange things such that the load cell is in air and the weighing platform is suspended under the water. If the water is in a tank or bucket, you could use the load cell to weight the mass of the container of water and the object in the water and again avoid the problem of making your enclosure watertight. May 29, 2021 at 23:47
• No. It is not going to be submerged in water. I need just a basic water resistance against splash. I want to fit this at the bottom of a cylindrical container (like a water bottle) that carries a liquid solution. It tells me the weight of the solution in the container. In a nutshell, somewhat like designing an analytical weighing balance that attaches to the bottom of a cylindrical container. May 30, 2021 at 0:54

Because 3d printing a hard case solution, will create a hard barrier which will affect the weight measurement, you'll probably need to consider some sort of flexible isolation method.

A quick (and not so eye pleasing solution) if

a) the project does not need to be submerged in water

b) if you are not so much bothered about appearances

is to consider isolating with a thin film of small weight. One possible solution for that (and depending on the size of the load cell would be to use an ultra thin transparent nylon bag.

You either

• put the load cell inside the plastic bag and zip-seal around the cable going in.

OR

• you could 3D print a box to house the load cell and then put on top a very loose plastic film.
• To be honest, I don't think wrapping it around a thin film would work. It will be fragile. Considering the working environment, I require it to be a little rugged. Just rugged enough to withstand a drop from lower heights. What I am unable to do is preserve the underlying principles of the config shown in the image1.If you observe, the left half of the load cell is in contact with the ground, and on the right half is the weighing platform which isn't in contact with the ground. When I design an enclosure in 2 halves(top&bottom),the right half of the load cell and the left half come in contact. May 30, 2021 at 2:49
• OK fair enough. Although you should update your initial post to add that specification (i.e. to be able to be dropped from a small height). Additionally (if that's the only drawback), depending on the material of plastic bag you can have different quite good abrasive properties (see nylon or silicone freezer bags)
– NMech
May 30, 2021 at 4:57

Hi I think a 2 part enclosure would work with this. You need to make sure you have enough tolerance between all of the components so that they do not interfere with the load cell accuracy. I have shown a design of the 2 part enclosure which makes the design water resistant by not allowing a large flow of water up the enclosure.