8. Recall System (how can we get them back for recalibration)
Once a calibrated instrument was returned back to the owner or released to be used again, you should have a recall system to get it back once it is due for calibration (this is applicable to a very large organization where there are different owners of instruments as per department or area).
This is one of the most difficult parts, where some owners do not care about their measuring equipment unless they are caught in an audit.
An effective recall system is one of the keys to having a successful calibration program where the owners of UUC are following the scheduled submission for recalibration without any delay (faithfully).
But usually, this is not always the case. I experienced the same problem in the past where some UUC (Unit Under Calibration) owners always fail to submit the instruments on time.
To solve this problem, I implement the below system with the support of the quality department. This solution is to copy their bosses together with the quality team in the email and then directly address the bosses during follow-up.
This is what I call “the escalation method”. This is a scheduled email message where every email sent has a corresponding higher authority to be copied (CC).
Below are the steps:
1. The first notification is to the instrument owner of UUC only. This is a usual reminder to submit the instrument.
2. The second notification is a follow-up message, but this time, his supervisor is in ‘CC’ (copied).
3. 3rd notification is to message directly to the supervisor (with the instrument owner) and copy the quality manager (Quality Department).
Now, since the instrument is already overdue and the quality team has been notified, they will tag or confiscate the equipment and then perform corrective action to correct the system (not the person).
9. Reference Standards (Equipment)
Reference Standards are the equipment we used to calibrate UUC, we compare and verify the accuracy of the UUC with respect to these reference standards. It has the capabilities of accuracy, stability, range, and resolution for the intended use.
A reference standard should have the following requirements:
Must be calibrated by a laboratory accredited to ISO 17025 with the required Calibration Certificate
Traceability to International Standards (BIPM)
Properly maintained and verified (see element 13)
Properly labeled, coded, and identified (related to element 7)
A calibration program is established – calibration interval, PM schedules, history file
As much as possible, at least 4 times more accurate than UUC to be calibrated.
10. Facilities and Environmental Control
There are no specific requirements regarding the layout of a laboratory, but there are requirements that we need to follow when choosing a lab, which is focused or concerned with the effect on the validity of results. This depends on the field or parameters that you will calibrate and the instruments/standards that come with it.
For example, if you are designing a lab that serves mass calibration, ensure that it is located on the ground floor to minimize the effect of vibration during calibration.
There are requirements that a lab must have as per ISO 17025: 2017, under clause 6.3 Facilities and environmental conditions.
Some requirements to consider that are related to the physical design of a lab are:
1. A room with a stable and clean environment.
2. There is enough space for proper separation or segregation in order to:
a. avoid confusion on what parameters to be calibrated during the staging of the instrument for calibration.
b. proper segregation or separation should be observed to avoid cross-contamination.
c. Some instruments or reference standards need to have a separate space because they are sensitive to temperature or humidity or other environmental factors. These can contribute to error in results and therefore needs to be separated. For example, temperature instruments cannot be mixed with dimensional instruments.
3. Controlled access to ensure security and confidentiality.
Environmental factors have a great impact on the calibration job. Whenever an environmental condition is not met, the calibration job should be stopped until it returns to normal.
Normal wherein, for example, a required temperature and humidity range that is prescribed is within the specified range. Since it is critical in our process, it is advisable to use a continuous recorder, a Thermo-hygrometer, to monitor and record.
Below are some examples of the environmental factors that we need to control:
temperature
humidity
vibrations
dust
lightings
