How often should an instrument be sent in for recalibration? Are there rules to follow? Calibration of instruments is done to verify their performance. While the device starts as calibrated in the beginning, several factors regarding the calibration frequency exist.
What is a Calibration Interval?
A calibration interval is a period established for a test instrument to be returned for recalibration. Recalibration provides the certainty that the device performs as well as or better than the manufacturer’s specifications.
Mechanical parts wear, and electronic components drift and perform differently over time. When purchasing an instrument, consider the build of it to see if there are components that will wear better than others. Manufacturers of products have the opportunity to factor it in when creating instruments. Manufacturer product specifications will give a reasonably accurate time frame for calibration intervals.
Variables that Can Affect an Instruments Performance
Several factors can significantly influence the rate of drift.
Some of these factors are:
- Temperature extremes
- Mechanical shock (dropping an instrument)
- Mechanical vibration (bouncing around)
- Frequency of use
Who is Responsible for Determining the Calibration Interval?
The instrument owner is responsible for determining calibration intervals for their instruments. In addition, they are in charge of knowing how the devices function and the conditions that they are being used in.
The international quality standards are not descriptive of what is required for calibration intervals. The critical aspect of a calibration interval is that it should be the period in which you can be reasonably confident that the instrument will meet its published specification or a specification the company has established.
Maintaining Proper Calibration
Within businesses, there is always the thought of economizing by extending the calibration intervals. However, extending a calibration interval can lead to the instrument no longer giving precise and accurate data. This can be very costly. For example, in manufacturing, this would mean that the products may have to be recalled due to safety concerns. Or in a pharmaceutical lab, the drugs they make to help the sick are not up to standards. Cutting back on calibration is not the answer.
Understanding the Calibration Due Date
The due date does not mean the calibration laboratory guarantees the product will remain within specifications. As noted above, other factors come into play when discussing drift and calibration needs. The business is the one that determines the due date. The manufacturer or calibration lab can merely suggest what should be considered.
Calibration Maintains Certification
In several industries, certification is a must for specific tasks. In this case, you must have up-to-date instrument calibrations to stay in business.
A calibration certificate documents vital information about a piece of equipment and its calibration details.
Calibration certificates must contain certain information to assure compliance with NIST calibrations or calibrations accredited to ISO 17025. For example, a calibration report gives a pass or a fail for each specific function. In addition, they adjust a device that does not meet the specifications and provide detailed information.