Except as provided in subsection (b) of this section, unless registered with the Secretary under § 11-204.3 or § 11-204.4 of this subtitle, a weight and measure may not be used or possessed for current use for: Buying or selling any commodity or object; Hire or award; Computing any charge or payment for services rendered on the basis of weight and measurement; or Determining any weight and measure for a charge. This section does not apply to counting scales.