loadometer

plural loadometers

1. A kind of weighing scales with a jack, for weighing vehicles while they are on the road.

   The second method was to use two loadometers under the wheels of one axle, mounting the wheels of the other axle on what we called "equalizing blocks" or "dummies." By that method the two axles are brought into the same horizontal plane […]

   1950, National Bureau of Standards Miscellaneous Publication, page 138

   1 more example

   In New Jersey, only specially trained men are allowed to enforce the axle-weight law. They are permitted to weigh only under certain conditions with loadometers, and, when in doubt, they move the vehicle to a location where axle weights can be determined on platform scales.

   1954, Report of the ... National Conference on Weights and Measures, page 75