The installation of an electronic truck scale requires the following approval procedures:
1.Land approval: Before installing an electronic truck scale, you need to apply for a land use certificate from the local ** land management department to ensure that you have the legal land use rights. 2.Planning approval: It is necessary to apply for a planning permit from the local ** planning department to ensure compliance with the local urban and rural planning and land use planning. 3.Construction permit: Before construction, it is necessary to apply for a construction permit from the local ** construction department to ensure compliance with construction specifications and safety requirements. 4.Metrological certification: As a measuring instrument, the electronic truck scale needs to apply for a measuring instrument manufacturing license from the national metrology certification department to ensure its accuracy and reliability. 5.Environmental approval: If the installation of the electronic truck scale will have an impact on the surrounding environment, it is necessary to apply to the local environmental protection department for an environmental assessment report to ensure that it meets environmental protection requirements. 6.Safety evaluation: A safety evaluation of electronic truck scales is required to ensure that their safety performance meets relevant standards and regulations. 7.Other approvals: Other relevant approval procedures may be required according to the requirements of the local **. 
In short, before installing an electronic truck scale, you need to understand the relevant regulations and requirements of the local **, and go through the corresponding approval procedures according to the requirements to ensure that the electronic truck scale is used legally and compliantly.