According to the durability test of non-automatic weighing instruments, it is necessary to use them normally
Under the condition of 50% maximum load, it can still perform 100,000 loading and unloading tests
Meet the requirement of not exceeding the maximum allowable error.
If a weighing instrument is used 100 times a day for 365 days in a year, then this weighing instrument is one
It is used 36,500 times a year. Compared with 100,000 times of loading and unloading, it's quite equivalent
Around 2.7. In fact, such durability tests and weighing instruments
The situation of conducting repeatability tests is quite similar, except for durability tests
The frequency is much higher and it is only carried out under a fixed load of 50%Max
Test.
The subsequent verification cycle for weighing instruments is usually stipulated to be half a year. will
The error range in use is specified as the maximum allowable error at the time of the first verification
Twice that of (MPE), that is, (2MPE). The maximum range is usually used
Weighing instruments weighing no more than 100 kilograms are mostly retail weighing instruments, and these weighing instruments
Most of them work at room temperature indoors, and their operating temperature does not exceed that of weighing instruments
Verification temperature (-10℃ to +40℃). Under normal circumstances, through durability
The weighing instruments for sex tests should not exceed the maximum allowable error for at least two years
(MPE). According to this condition, can it be considered that the weighing instrument is two years after the first inspection
The error range in use will not be exceeded within the year, and the verification cycle can be extended
A lot of time? On the other hand, to ensure that the weighing instrument can withstand a hundred thousand times
The loading and unloading tests should have corresponding technical provisions in the weighing instrument standards
The requirements are reasonable.
2
The durability of truck scales
As early as the 1970s and 1980s, in order to meet the needs of users
Some weighing instrument manufacturers have begun to increase the maximum weighing capacity of truck scales
The rated value of segmented weighing. However, to the surprise of most people
Yes, under such loads, weighing instruments will still suffer from unexpected knots
Irreversible damage to the structure. Despite this, the manufacturer still regards the weighing instruments
The scale value is set very high, but the user is informed that the load of the truck scale needs to be limited
Within the load limit permitted by the expressway. At that time, there were truck scales all over the world
There is no definite conclusion on how to stipulate the carrying capacity. Only the United States is doing this
Some exploratory work was carried out, attempting to seek regulations on the load capacity of truck scales
A consistent approach
In 1986, the International Weighing and Measurement Conference was held in Albuquerque
Discuss the National Conference on Weightings and Measures (Jane
At the annual meeting of NCWM, this issue was raised in an informal conversation
It received attention and thus formed a production line at a temporary meeting in 1987
The working group of the industry is reviewing the definitions of maximum weighing capacity and segmented weighing capacity
Work. Subsequently, in 1987, the technical conditions and tolerances of NCWM were specified
Specifications and Tolerances (abbreviated as S&T) consider proposing
Come up with a solution to this problem.
At the 1988 extraordinary meeting, the Weighing Instrument Manufacturers Association (Scale
Manufactures Association, abbreviated as SWA, has proposed the ratings
The concept of concentrated load was proposed and approved by the S&T committee. SWA
The suggestion is to link the nominal weighing capacity of the truck scale with the rated concentrated load
The concentrated load weighing (CLC) value is specified by the manufacturer and is set for weighing instruments
The maximum concentrated load value that can be achieved is calculated, which is equivalent to the nominal weighing of the truck scale
The relationship between them is as follows:
The maximum weighing capacity is ≤CLC× (N-0.5), where N is the number of sections of the truck scale.
Such a representation can eliminate the incorrect representation of the weighing capacity of the truck scale.
To ensure that the maximum load reaches the CLC load during the segmented loading test
It can still operate normally when the value is reached, and the load during use does not exceed the CLC value
Ensure the safety and reliability of the truck scale. In the 1989 edition of Manual 44 of the United States
The above has been modified, adding the maximum weighing capacity mentioned above.
The requirements for the relationship between concentrated load weighing and the number of segments between weighing instruments.
Here, it is particularly necessary to put forward the technical requirements for dynamic truck scales.
It is to meet the technical requirements in a state of motion and must be established on
Dynamic tests, technical conclusions are obtained under dynamic environmental conditions, rather than
The result of statics through stress calculation. The requirements under dynamic conditions are correct
The weighing instrument industry, in terms of technology, experience, human resources and finance
To reach a satisfactory technical conclusion in terms of force, in practical operation, there are
In great difficulty. However, regarding whether it is necessary to add CLC techniques
What are the surgical conditions and how to determine the CLC value? There have been many considerations since 1988
Both the manufacturers of weighing instruments and international conferences related to weighing instruments have presented various proposals
Neither the plan nor the experiment reached a conclusion. It was not until the 1994 annual meeting that
Metter-Toledo proposed to borrow from the Federal Highway Administration regarding
Bridge gross load formula B (Federal Highway Administration's
Bridge Gross Weighting Formula B) to determine the amount of CTC
Fixed value. This formula is used to protect when vehicles pass through due to excessive concentration
The rated load that causes bridge damage due to medium load is the most specified in the formula
The requirements for safety protection of near dynamic truck scales only need to divide the truck scale into points
Segments or modules are considered equivalent to bridge interval loads. I think the regulations on the durability of weighing instruments should be included in international recommendations,
Specify the purpose, methods and requirements of the durability test for this weighing instrument
In addition, it can also be used to stipulate CLC ratings for dynamic vehicles
The technical requirements for preventing damage to weighing instruments caused by vehicle overload should be met
The same results from durability tests, this is my assessment of the durability of dynamic cars
The perspective of sexual demands.