Problem Solving Challenge

Is there a way to weigh a scale itself, without using another scale?

I'm weighing all my luggage and belongings to fit in my car with an electronic scale.
The thought occurred to me, I do not know the weight of the scale.
Of course it's not important, but it's a funny thought.

How can I figure out the weight of my scale using the scale itself, without another scale?

Can a solution exist? I'm thinking with some ropes and pulleys kind of thing there might be a way to do this. Or is there an obvious easy way that's right in front of me?

And no comparing its weight to other objects that it weighs. Like if you used a balance to compare that the scale is heavier than a book and lighter than a suitcase, then weighed the book and suitcase to estimate the weight of the scale. No, that wouldn't count

It has to somehow weigh itself. More like this. When I weigh my suitcase, I stand on the scale and check my weight, then I stand on it again with the suitcase. I subtract the difference between the two weights to get the weight of the suitcase. That kind of thing. It has to be fairly precise.

Can I somehow get a reading of the weight of me and the scale together? Maybe by weighing on a special surface that will reduce the weight of me on the scale, proportional to the weight of the scale somehow?