All weighing or measuring devices in this state must be supervised and controlled by the commission. A variance permit for the installation or relocation of a device deviating from requirements under this chapter may be issued by the commission when the device meets service requirements within accepted tolerances. The commission may request that an application for a variance permit include complete construction plans and a statement of the specific reasons why deviations are necessary or desirable. The commission may impose limitations or conditions on the construction and use of any weighing or measuring device.