What is the difference between Onsite vs. Offsite Calibration?
Professional calibration laboratories meet ISO 17025 standards since they control the environmental conditions (i.e. temperature, humidity, air flow, and direct sunlight) and use the proper equipment (ultra-micro balances situated on marble tables).
Onsite service providers often times cannot control the environmental conditions where they are performing calibration, and their equipment used (balances) may not be accurate due to frequent transportation and mishandling. It has been noted by The American Association for Laboratory Accreditation (A2LA), that higher measurement uncertainties are expected from onsite calibration. All of these factors greatly contribute to the accuracy, legitimacy, and overall calibration results. For more information, please see the A2LA Policy P104.