Building a calibration plan

If your business uses sensors, thermometers, probes, loggers or other measurement instrumentation, calibration will be an essential process within your operation. But how structured is your approach to calibration? Do you have a planned schedule? Taking a structured approach to calibration, ensuring that the right devices are calibrated at the right time, in the right place and to the right standards can help streamline the process of calibration, and keep you operating efficiently and effectively.

In this article, we’ll look at the reasons to have a calibration plan and the steps to building one that is robust, workable and adds value to the business.  

Why have a calibration plan?

• Accreditation

Accreditation is an important way to promote confidence in the quality of your product or service, differentiate yourself from competition, or may even be required in order to operate. For example, ISO 9001 for quality, Therapeutic Goods Administration (TGA) accreditation for pharmaceutical products, or ISO 17025 for businesses that include testing laboratories. If you’re looking to achieve or renew one or more of these, you’ll need to be able to show a clear plan for calibrating the instruments that help you meet your quality goals.

• Quality system

Even if you’re not requiring formal accreditation for your business, you will almost certainly have a quality management system. The way in which you calibrate instrumentation to assure quality is an important element of that plan – giving your customers confidence that you have a strategy and a schedule for calibration. Your calibration plan should be clearly documented as part of your quality management system.

• Risk management

The third reason to have a calibration plan is to reduce and manage risk. Inaccurately calibrated equipment represents a source of risk to your business: if quality is not maintained, you risk losing customers; if processes do not deliver the desired outcome, materials may be wasted, causing unnecessary cost; if a fridge registers an inaccurate temperature and food becomes unsafe, you risk financial penalties, public health incidents, a loss of reputation and even the cost of legal action.

How to create a calibration plan

Every business that uses measurement instrumentation needs a calibration plan, so here’s our five-step guide to creating one:   

1. Check the NATA guidelines

NATA provides a Calibration Reference Equipment Table, which you can download from their website. Whilst many organisations start and end with this table, it should really be thought of as the ‘baseline’, as it offers minimum requirements for each equipment type. Many organisations see following the guidelines in the table as a way of feeling safe that they are covered from a legal point of view. The NATA guidelines are essentially a minimum standard, and if you want to do more than the bare minimum, there are some other factors to take into account when building your calibration schedule.  

2. Application

The same equipment, used in two different settings may have very different calibration needs. The application and environment should therefore be taken into account when building your plan. Equipment that is used in dirty or dusty conditions, or where it receives shocks or temperature changes will need calibrating more frequently than that used in a relatively clean environment. For example, InfraRed (IR) guns used in construction or mining, or temperature sensors in smelters, may need a shorter cycle between calibrations than probes in a food production setting. You should take application into account when creating your schedule.

3. Tolerance requirements

If your business is one that needs to operate within very tight margins of variation, or where product quality absolutely depends on a very precise measurement, then calibration becomes far more critical. For example, a medical research laboratory where the value of the research work is very high and allowable tolerances very low would need more frequent calibration than sensors in a warehouse. So consider tolerances and impact when creating your schedule.

4. Manufacturer recommendation

The manufacturer of the sensor may indicate a calibration schedule based on specific features of their product. It’s always advisable to follow the manufacturer’s guidelines, so if their suggested schedule is more frequent than what you have planned based on application and tolerance, it’s a good idea to increase the frequency to meet their recommendation. 

5. Common usage in the industry

The final ‘sense check’ is what others in your industry do. Whilst no two businesses are identical, and your plan will depend on the level of accuracy you need, the intensity and use of your equipment, nevertheless if you are way out of line compared to what your industry peers are doing, it might be a sign that you’ve missed something and need to review the plan.

Plan the schedule, schedule the plan

Once your plan is built and documented, make sure it is implemented. If the instruments can be sent away for calibration, create a schedule to minimise the impact on production systems and allow time for getting it to/from the specialist lab. If it needs to be calibrated at your premises, ensure you book in good time to ensure the timing you need.

Finally, as you bring new equipment into your business, don’t forget to go through the steps above for all your latest instrumentation.

With a well thought out, documented and implemented calibration plan, you can have confidence that your instrumentation will always be ready to do its job of ensuring the highest quality in your operation.

ECEFast – temperature made simple.