Select the appropriate instrument model according to the operation scenario (such as service rig, Christmas tree, mud tank), inspect the instrument appearance and sealing performance, prepare installation tools, seals and wiring cables; confirm the installation position (pressure instruments are installed at the place where the medium flows smoothly, temperature instruments are inserted into the medium to the required depth, and flow instruments ensure the length of front and rear straight pipe sections meets the standard) Fix the instrument at the preset position, connect the pressure joint, temperature sleeve and flow straight pipe section to ensure tight sealing and no leakage; wiring (signal cable, power cable) is standardized, and the shielding layer is grounded to avoid interference; install auxiliary components (filter, globe valve) to protect the instrument. Turn on the power, start the instrument, and check whether the display is normal; calibrate the instrument with standard calibration equipment (standard pressure gauge, standard thermometer, standard flow meter), adjust parameters to ensure the measurement error is within the allowable range; link the automation system to test whether the signal transmission is stable and the data is accurately uploaded. When the instrument is in normal operation, real-time observe the pressure, temperature and flow parameters displayed on site to confirm whether they are within the set range; check the data transmission through the remote monitoring system, timely find abnormalities (such as sudden parameter changes, signal interruption), and troubleshoot faults (such as leakage, loose wiring). Regularly clean the instrument surface and sensor to prevent sand dust and medium adhesion from affecting measurement; inspect seals and cables, and replace damaged components in time; regularly inspect vulnerable components (such as thermocouples, turbines) to ensure normal operation of the equipment; record operation data and retain maintenance records. According to the use scenario and standard requirements, conduct a comprehensive calibration of the instrument every 6-12 months to ensure the measurement precision continues to meet the standard; timely repair or replace unqualified instruments to avoid affecting operational safety and data accuracy.