temperature sensors and thermometers must be used within the validity period of calibration. In case of repair or replacement, the personnel of packaging preparation post shall timely fill in the 《Packaging Department Cold Storage Change Registration Form》in the 《Packaging Department Cold Storage Operation Record》(DX-RD-EQ-PAD003), and contact the maintenance personnel of engineering equipment department to verify the repaired or replaced temperature sensor and thermometer, which can be used only after they are qualified.