Measurement around you - electronic truck scales
As the first energy banner of Ordos City, Zhunger Banner relies on rich coal resources and has a large number of coal mines and coal chemical enterprises. As an important measuring instrument for coal mines and large enterprises, electronic truck scales play a pivotal role in trade settlement. Today, let's talk about the measuring instrument of electronic truck scales.
1. What is an electronic truck scale?
Electronic truck scales are used to measure the weight of trucks, and it also has a common name - weighbridge. There are two types of electronic truck scales: analog truck scales and digital truck scales, which are widely used in the weighing of bulk goods.
(1) The structure of the electronic truck scale
The electronic truck scale is mainly composed of carriers, weighing display instruments, load cells, connectors, limit devices and junction boxes and other components, and can also be equipped with external equipment such as printers, large display screens, computers and weighing management software and stabilized power supplies. In addition, the electronic truck scale can also be connected to other external equipment according to the needs, such as combined with printing equipment, by connecting to the computer to print and calculate the data, and use relevant software to save and compare the data. There are also connections to other display screens to meet different needs.
Electronic truck scale specifications and models are generally represented by SCS, and its meanings are as follows:
S (the first): the category of the scale - ground scale, truck scale;
C: Force transmission structure - sensor;
S (second): Digital display.
(2) Working principle
The weighed object or the truck is placed on the bearer table, under the action of gravity, the gravity is transmitted to the load cell through the carrier, the load cell elastomer is deformed, the strain gauge bridge attached to the elastomer is out of balance, and the output is proportional to the weight value, the signal is amplified by the linear amplifier, and then converted into a digital signal through A/D, and the weight data is directly displayed after the weight signal is processed by the microprocessor (CPU) of the instrument. After the printer is configured, the weighing data can be printed and recorded, and if the computer and weighing management software are configured, the measurement data can be comprehensively managed through the weighing management system.
2. Compulsory verification of measuring instruments
According to the State Administration for Market Regulation's "Catalogue of Measuring Instruments for Compulsory Management", the electronic truck scale used for trade settlement is a non-automatic scale, which is a national compulsory verification measuring instrument, in order to ensure the accuracy of its measurement performance, it should be carried out by the local legal metrology verification agency for periodic compulsory verification.
(The inspector is conducting metrological verification on the electronic truck scale)
(The inspector is installing a lead seal on the electronic truck scale weighing instrument)
After the verification of qualified electronic truck scales, the measurement verification personnel will post the verification mark on the weighing display instrument, issue the verification certificate, and at the same time install the lead seal of the verification mechanism at the junction box below the weighing display instrument and the scale body (some electronic truck scales do not have junction boxes). The verification period is 1 year.
Fourth, legal management
A lead seal is a physical marking with a seal of metallic lead or lead alloy to prevent any unauthorized adjustment of parameters related to the measurement performance of the scale or the removal of parts, etc. The user shall not destroy and remove the seal, after the seal is destroyed, the qualification will be invalid. Article 11 of the Regulations on the Administration of Metrology of the Inner Mongolia Autonomous Region clearly stipulates that the following behaviors shall not be used in the use of measuring instruments: (3) Breaking the seal of measurement verification.
(Seals attached to the weighing scale)
(Attached seal on junction box)
5. How to use the electronic truck scale correctly
(1) After the electronic truck scale for trade settlement is installed, it must be verified and qualified by the local legal metrology verification agency before it can be put into use.
(2) Before use, first check whether the scale body is flexible and whether the performance of each supporting part is good.
(3) After the instrument is turned on, it can be used only after the zero point is stable.
(4) When the vehicle enters the weighing platform (or places heavy objects as gently as possible), the speed should be less than 5km/h, and then brake slowly, and measure after the car stops.
(5) Stay in the center of the platform as much as possible.
(6) The meter reading must read the correct value of the weight when the "steady" indicator is on.
(7) It is strictly forbidden to overload weighing electronic truck scales.
(8) Clean the electronic truck scale frequently, especially the items scattered on the weighing platform should be cleaned up in time.
(9) If the electronic truck scale fails, it should be stopped immediately and reported to a professional for repair, and it can only be used after passing the inspection.
(10) The electronic truck scale should be used within the validity period of the verification. When it is about to expire, it is necessary to apply for compulsory verification to the local legal metrology verification agency in advance.
Sixth, the maintenance of electronic truck scales
(1) In order to ensure the accuracy of the system, avoid wind and rain erosion, and facilitate the operation, it is required to set up a shed and a measuring scale room.
(2) There should be a 10-15mm gap at the junction of the weighing platform and the slope, and no collision and friction shall occur.
(3) The weight of the truck to be measured should not exceed the rated weight of the system.
(4) In order to ensure the normal measurement of the scale, it should be verified regularly.
(5) The lower part of the weighing platform shall not be stuck with foreign objects.
(6) The operator of the scale must be trained to operate, and the repair personnel shall not disassemble any parts at will before mastering the necessary knowledge, so as not to affect the measurement accuracy or damage the system.
(7) Before the system is powered on, the power supply and grounding device must be checked to see if they are reliable, and the power supply must be unplugged and cut off when the power supply is stopped.
(8) The battery of the weighbridge instrument can not be charged for a long time and lose power, and it is recommended to charge and discharge it once a month.
(9) Fully do a good job in the lightning protection of the electronic truck scale to avoid the damage of lightning strikes to the electronic truck scale.
Contributed by Liu Lu
Editor: Qin Jiayao
Proofreader: Liu Xiaoyu
Review: Diao Haiqian