What is Calibration Intervals?

Calibration intervals are the period of time established for a test instrument to be returned for recalibration.  Recalibration provides the certainty that the instrument is performing as good as or better than the manufacturer’s specifications.

Mechanical parts wear and electronic components will all drift and perform differently over time.  When purchasing an instrument take into account 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 fairly accurate time frame of calibration intervals.

Variables that Can Affect an Instruments Performance

Several factors can significantly influence the rate of drift.  Some of these factors are:

• Humidity
• Temperature extremes
• Mechanical shock (dropping an instrument)
• Mechanical vibration (bouncing around)
• Frequency of use

Who is Responsible for Determining the Calibration Intervals?

The instrument owner is responsible for determining calibration intervals for their instruments.  They are the ones who know specifically how the instruments and the conditions they get the most usage in.

The international quality standards are not descriptive about what they require for calibration intervals.  The key aspect of a calibration interval is that it should be the time period in which you can be reasonably confident that the instrument will meet its published specification or a specification that the company has established for the instrument.

Maintaining Proper Calibration

Within businesses, there is always the thought about economizing by extending the calibration intervals.  However, extending a calibration interval can lead to situations where the instrument no longer gives precise and accurate data.  This can be very costly.  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 that the calibration laboratory guarantees that the product will remain within specifications.  As noted above, there are other factors that come in to play when discussing drift and calibration needs.  The business is the one who determines the due date, the manufacturer or calibration lab can merely suggest what should be considered.

Calibration Maintains Certification

In a number of industries, certification is a must specifically for certain tasks. In this case, you must have up-to-date calibrations on your instruments to stay in business.

A calibration certificate documents vital information about a piece of equipment and details surrounding its calibration.

Calibration certificates must contain certain information to assure compliance with NIST calibrations or calibrations which are Accredited to ISO 17025.  In the final analysis, a calibration report gives a pass or a fail for each specific function.  They adjust a device that does not meet the specifications and provide explicitly detailed reports.