A set of scales.
If it has two pans, like the scales of justice, it is typically referred to as a set of scales (plural). If it only has one pan, it is typically referred to as a scale.
balance its true
A set of scales and calibrated masses.
A set of scales comes to mind.
A set of scales
This is "zeroing" the mass value given by a set of weighing scales, to cancel out the mass of whatever is already on the scales.
A set of scales
A set of Digital scales.
tribulation
It is a set of scales large enough to weigh a vehicle. It is set into the ground so that vehicles can drive onto it.
A blindfolded woman holding up a set of weighing scales.