Calibration certificates refer to documented verification issued by accredited laboratories or companies, confirming that equipment meets specified standards. These certificates are not tied to a specific brand but are essential in industries like manufacturing, healthcare, and aerospace. Companies such as Fluke Corporation (USA) or Tektronix (USA) provide calibration services, ensuring devices like multimeters, oscilloscopes, and sensors comply with ISO/IEC 17025 standards. Calibration certificates validate accuracy, traceability, and reliability, serving as critical quality assurance tools across technical sectors.