Section 600.320  Scales Used for the Enforcement of Highway Weight Laws

The following procedures will be used to determine the certification of scales used for the enforcement of highway weight laws.  These procedures will determine if a scale(s) is to be certified or condemned.  Theses rules supersede those published in the National Institute of Standards and Technology's Handbook 44.

a)         A minimum build up test with known test weights shall be conducted as follows:

1)         portable wheel load weigher scale – 10,000 pounds

2)         all other scales – 20,000 pounds

            A minimum of two known test weight loads shall be applied, normally at the capacity of test weight load and another at one half capacity of the test weight load to each scale.

b)         A 40,000 pound minimum strain load test shall be conducted only on a vehicle scale, a scale that is adapted to weighing the entire vehicle at one time.

c)         One decreasing load test shall be conducted at approximately one-half of test weight capacity.  If multiple scales are used in combination, a decreasing load test shall be performed on at least one scale.

pounds

d)         At least one repeatability test shall be conducted. Any errors found shall agree within the absolute value of the maintenance tolerance for that load, and shall be within applicable tolerance.

e)         The tolerances to each of the above tests shall be those listed in the scale code of the latest edition of the National Institute of Standards and Technology's Handbook 44.

f)         All new scales and associated equipment must have a certificate of conformance issued by the National Type Evaluation Program.

g)         Electronic indicating elements equipped with recording elements shall be equipped with effective means to permit the recording of weight values only when the indication is stable within plus or minus three scale divisions.

h)         The maximum scale division shall be 100 pounds.

i)          For axle, portable axle, and wheel load weigher scales, a vehicle must be in a reasonably level condition at the time the weight is being determined. Reasonably level means the vehicle must remain stationary during weighing without the use of any braking force.

j)          For all other scales used to determine the weight of axles when part of the truck is not resting on a scale, the vehicle must be in a reasonably level condition at the time the weight is being determined.

k)         All scales used for the enforcement of highway weight laws shall be certified at least once every twelve months.

l)          Any registered serviceperson of the Illinois Department of Agriculture has the authority to place into service scales used for the enforcement of highway weight laws if the serviceperson conforms to the procedures listed above.

(Source:  Amended at 23 Ill. Reg. 8813, effective July 26, 1999)