What’s the difference between verification and calibration? Which instruments are classified as instruments subject to mandatory calibration?

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Verification and calibration may seem similar, but they are actually different. Both fall within the scope of metrology; in both cases, a standard instrument with higher accuracy than the instrument being measured must be used for comparison, so as to determine the indication error. In other words, both verification and calibration are important means of achieving traceability and crucial measures for ensuring the accuracy and consistency of measurement values. However, there are many differences between them, and their concepts must not be confused. Since April 1 this year, when the free mandatory calibration of instruments came into effect, many people have been wondering which devices qualify as instruments subject to mandatory calibration. This article will help you make that determination. yunrun%2ecom%2ecn%2ftech%2f2638%2ehtml Nine key differences between verification and calibration: 1. Different purposes – Verification involves a mandatory, comprehensive assessment of the measurement characteristics. The quantitative values are standardized to verify whether they meet the specified requirements. It is a top-down transmission of values. Calibration – Determine on your own whether the values of monitoring and measuring devices are accurate. It belongs to bottom-up value tracing to evaluate the indicated error. 2. Different objects: Verification – **Mandatory verification: Metrological reference standards ； Metrological standard ； There are 59 types of working measuring instruments used for trade settlement, security protection, healthcare, and environmental monitoring. Calibration – measuring instruments and devices other than those subject to mandatory verification. 3. Basis varies – Inspection procedures uniformly formulated by **-authorized metrology departments. Calibration – The calibration specifications or methods can be **uniformly prescribed, or they may be determined by the organization itself. 4. Different nature: Verification is mandatory; it is a law-enforcement act falling under the scope of legal metrology management. Calibration – it is not mandatory and represents a voluntary traceability action by the organization. 5. Different cycles: Inspection – carried out in accordance with the mandatory inspection cycles specified by Chinese law. Calibration – determined by the organization based on its usage needs; it can be performed regularly, irregularly, or prior to use. 6. Different methods: Certification can only be carried out at designated certification agencies or organizations that are legally authorized to do so. Calibration – can be self-calibration, external calibration, or a combination of both. 7. Different content: Verification – involves a comprehensive assessment of the metrological properties, including an evaluation of the magnitude of errors. Calibration – assess the indicated error. 8. Different conclusions: Verification – Based on the range of value errors specified in the verification regulations, a decision is made as to whether the product is qualified or not, and a verification certificate is issued. Calibration – it does not determine whether the device is compliant or not; only the indication error is assessed, and a calibration certificate or report is issued. 9. Different legal effects: The certification report is a document with legal effect, serving as the legal basis for the certification of measuring instruments or devices. Calibration – The calibration conclusions are technical documents that have no legal validity. Calibration refers to the activity carried out by legal metrology departments or organizations authorized by law, in accordance with calibration procedures and through experiments, to provide evidence confirming that the indication error of measuring instruments meets specified requirements. Calibration refers to adjusting machines, instruments, etc., to ensure their accuracy. A set of operations, under specified conditions, to determine the relationship between the value indicated by a measuring instrument or measuring system, or the value represented by a physical standard or reference material, and the corresponding value reproduced by a standard. Calibration may include the following steps: inspection, correction, reporting, or eliminating any accuracy deviations in the measured devices being compared through adjustments. Appendix: List of Working Measuring Instruments Subject to Mandatory Verification in the People’s Republic of China (issued by the **Bureau of Metrology on May 28, 1987). I. This list is formulated in accordance with Article 16 of the Regulations on the Management of the Verification of Working Measuring Instruments Subject to Mandatory Verification in the People’s Republic of China. II. The measuring instruments listed in this catalog are the specific items included in the \"Catalogue of Working Measuring Instruments Subject to Mandatory Inspection in the People’s Republic of China\". For items listed in this catalog that are used for trade settlement, safety protection, medical and health care, and environmental monitoring, mandatory verification is required. Specific items include: 1. Rulers: bamboo/wooden straight rulers, telescopic rulers, steel tape measures, steel tape measures with hammers, and railway gauge rulers ； 2、Area meter: Leather area meter ； 3. Glass liquid thermometer: Glass liquid thermometer ； 4. Thermometer: Thermometer ； 5. Petroleum flash point thermometer: Petroleum flash point thermometer ； 6. Grain moisture meter: Grain moisture measuring device ； 7. Calorimeter: Calorimeter ； 8. Weights: weights, chain weights, additional weights, fixed-weight weights ； 9. Balance: Balance ； 10. Scales: beam scales, small weighing scales, platform scales, floor scales, belt scales, hanging scales, electronic scales, luggage scales, postal scales, scales specifically used for pricing and charging, grain vending machines ； 11. Quantitative packaging machine: Quantitative packaging machine, quantitative filling machine ； 12. Track scale: Track scale ； 13. Capacity container: Grain bulk density meter ； 14. Metering tanks, metering tank trucks: vertical metering tanks, horizontal metering tanks, spherical metering tanks, road-based metering tank trucks, rail-based metering tank trucks, ship-based metering tanks ； 15. Fuel dispenser: Fuel filling machine ； 16. Increase liquid volume: Raise liquid amount ； 17. Edible oil dispenser: Edible oil dispenser ； 18. Alcoholmeter: Alcoholmeter ； 19. Density meter: Density meter ； 20. Sugar meter: Sugar meter ； 21. Milk meter: Milk meter ； 22. Gas meter: Gas meter ； 23. Water meter: Water meter ； 24. Flow meters: liquid flow meters, gas flow meters, steam flow meters ； 25. Pressure gauges: pressure gauges, air pressure gauges, oxygen gauges ； 26. Sphygmomanometer: Sphygmomanometers, blood pressure monitors ； 27. Tonometer: Tonometer ； 28. Car odometer: Car mileage meter ； 29. Taxi mileage meter: Taxi mileage meter ； 30. Speed detector: Highway speed monitoring device ； 31. Vibration meter: vibration monitoring device ； 32. Electricity meters: Single-phase electricity meters, three-phase electricity meters, time-of-use electricity meters ； 33. Measuring instrument transformers: current transformers, voltage transformers ； 34. Insulation resistance and ground resistance testers: Insulation resistance testers, Ground resistance testers ； 35. Field strength meter ； Field strength meter ； 36. ECG, EEG machines: ECG machines, EEG machines ； 37. Dosimeter (including medical radiation sources): Dosimeter, medical radiation sources ； 38. Ionizing radiation protection instruments: radiation monitors, dose rate meters, radioactive surface contamination detectors, personal dosimeters ； 39. Activity meter: Activity meter ； 40. Laser energy, power meter (including medical laser sources): Laser energy meter, laser power meter, medical laser sources ； 41. Ultrasonic power meter (including medical ultrasonic source): Ultrasonic power meter, medical ultrasonic source ； 42. Sound level meter: Sound level meter ； 43. Audiometer: Audiometer ； 44. Hazardous gas analyzers: CO analyzer, CO2 analyzer, SO2 analyzer, hydrogen detector, hydrogen sulfide detector ； 45. pH meter: pH meter, blood gas acid-base balance analyzer ； 46. Gas meters: Gas alarms, gas detectors ； 47. Mercury detector: Mercury vapor analyzer ； 48. Flame photometer: Flame photometer ； 49. Spectrophotometers: visible light spectrophotometers, ultraviolet spectrophotometers, infrared spectrophotometers, fluorescence spectrophotometers, atomic absorption spectrophotometers ； 50. Colorimeter: Filtered photometric colorimeter, Fluorescent photometric colorimeter ； 51. Smoke and dust measuring instruments: Smoke measuring instrument, Dust measuring instrument ； 52. Water quality pollution monitors: water quality monitors, comprehensive water quality analyzers, cyanide detectors, dissolved oxygen meters ； 53. Exhaled breath alcohol detector: Inhaled breath alcohol detector ； 54. Blood cell counter: Electronic blood cell counter ； 55. Diopter meter: A diopter meter. III. The metrology administrative departments of the people’s governments in various provinces, autonomous regions, and municipalities directly under the Central Government may determine the specific projects to be implemented based on this catalog and in light of the actual conditions of their respective regions. IV. The administrative department for metrology under the State Council is responsible for the interpretation of this catalog. V. This catalog shall come into effect as of July 1, 1987. ①Added on January 19, 1999: 56. Electronic timing and metering devices: Telephone timing and billing devices ； 57. Cotton moisture meter: Cotton moisture measuring device ； 58. Optometer: Optometer, optometric lens set ； 59. Microwave Radiation and Leak Meter: Microwave radiation and leak meter. ②Added on October 26, 2001: 1. Gas filling station: Gas filling station ； 2. Heat meter: Heat meter. ③Cancelled on December 27, 2002: Car odometer: Car odometer. [Changhui Instrument Network Reminder] To determine whether the instruments and equipment in a laboratory are subject to mandatory calibration, the following two conditions must be met: 1. The instruments and equipment are listed in the Catalogue of Working Measuring Instruments Subject to Mandatory Calibration in the People’s Republic of China (i.e., the equipment specified in the appendix above) ； 2. The fields of application are: trade settlement, security protection, healthcare, and environmental monitoring.