Reference Device Tracking and Calibration Due Dates

Every result a calibration laboratory issues rests on the reliability of the reference devices used in the measurement. Once a reference device passes its calibration due date, the assurance behind the measurements made with it becomes open to question. In this article we look at why reference device tracking matters, where manual tracking struggles, and what calibration software can offer a laboratory in this area.

What is a reference device and why is it tracked?

A reference device is a measuring instrument of known accuracy that serves as the basis of comparison when customer devices are calibrated. The result reported for the customer's device is linked, through the reference device's own calibration, to references at a higher level. This link is called traceability, and it is the foundation of confidence in measurement results. ISO/IEC 17025, the standard that defines the general requirements for the competence of laboratories, also expects records to be traceable. For this reason, regularly monitoring the calibration, maintenance and check status of reference devices is an inseparable part of a laboratory's daily work.

The risk of a reference device past its calibration due date

A reference device whose calibration has expired usually keeps working, and nothing looks wrong from the outside. That is exactly where the risk lies, because there is no longer documented evidence that the device still measures with the expected accuracy. Certificates issued with such a device may be questioned, and the laboratory may have to re-evaluate the jobs involved. This can lead to lost time as well as damaged customer trust. Fixing the problem afterwards is generally far more demanding than preventing it in the first place.

The risk may not be limited to a single certificate. Because the same reference device is used in many jobs, every document issued until the expiry is noticed may have to be reviewed. For laboratories, the real goal is therefore not to detect afterwards that an expired device was used, but to give it no chance of being used at all.

The difficulties of manual tracking

Many laboratories track their reference devices in a spreadsheet, a calendar or a set of folders. This works while the number of devices is small, but weak points appear as the device count and the workload grow. The most common difficulties are these:

• The tracking list often lives on one person's computer or in their memory, so the information is hard to reach when that person is away.
• Dates are updated by hand, which always leaves room for forgetting or mistyping.
• The person preparing a certificate has to check separately whether the reference device they used is still current.
• In busy periods this check can be skipped, and the mistake only surfaces during an audit or when a customer asks.

Calibration, maintenance and checks tracked in one place

A calibration tracking program gathers the information on reference devices in a shared record that everyone involved can reach. In KALDATA, the calibration, maintenance and check tracking of reference devices is carried out within the same software. When a reference device is sent to another laboratory, external calibration tracking is handled in the same place as well. The answer to the question of which device is in what state then depends on the record rather than on individuals.

Having the dates visible in one place makes it easier to notice upcoming calibrations in time and to remind the people responsible. The laboratory can plan ahead for the period when a device will be away for calibration and arrange its work schedule accordingly. Being prepared, rather than finding out at the last minute that a due date has passed, reduces both disruption and rushed decisions.

An expired reference device is not added to the certificate

The real value of tracking is that the information comes into play while the certificate is being prepared. In KALDATA, a reference device whose calibration has expired is not added to the certificate, and the user is warned. The check is therefore not left to the technician's attention or to their memory on a busy day. The error is prevented before it occurs, not discovered after the certificate has reached the customer. A technician who sees the warning notices the situation immediately and knows that a reference device with a valid calibration is needed.

A preventive control of this kind also lightens the load on the quality manager. Instead of checking the status of the reference device on every certificate one by one, they can give their attention to matters that truly require judgement. For the technician, too, the rule is clear and does not vary from person to person.

Using the current record on the certificate

In a manual setup, reference device details are often copied from an older certificate or template. When the device is recalibrated, those details have to be updated in every file one by one, and a file that is overlooked may keep producing certificates with outdated information. This risk drops noticeably when reference device details are taken from the shared record. The person preparing the certificate uses the registered device instead of retyping the information. This approach reduces typing errors and makes record keeping and traceability easier.

Conclusion

Reference device tracking is the quiet but fundamental support behind the confidence placed in a laboratory's results. Calibration software does not remove the laboratory's responsibility, but it stops tracking from depending on individuals and helps prevent a mistake from reaching the certificate. Before making the move, drawing up a current list of the reference devices in use and verifying their latest calibration documents is a good first step. To learn more about reference device tracking and the other modules, you can visit the KALDATA Calibration Laboratory Management Software page. If you would like to see the software applied to your own processes, request a demo.