An instrument is a device or device used to detect, measure, observe and calculate various physical quantities, physical components, physical parameters, etc.. Vacuum leak detector, pressure gauge, length measuring instrument, microscope, multiplier and so on all belong to instrument and meter. In practical work, we often use the instrument is divided into two categories: Automation Instrument and portable instrumentation, automation instrument refers to need fixed installation in the field of instrument, also known as the installation instrument or dial instrument installation, this kind of i...