In our local city, there’s a sustainable shop that is entirely packaging-free. It’s not big, nor are there many products, but you can buy a lot of your basic needs there, provided you bring your own containers. It’s a concept that has gained some traction in recent years in an effort to reduce the environmental impact of mass-produced consumer goods. The main target is plastic packaging and its impact on pollution. Yet it remains a solution that is yet to be employed to its fullest potential.
In the Netherlands, supermarket chain Albert Heijn has introduced a packaging-free range of products. Although self-checkout systems in supermarkets are nothing new, this still heralds an expansion for these systems. This, in turn, also increases the demand for the manufacture and calibration of the scales for these systems. NMi, which specialises in testing, certification and training in the field of metrology, was able to meet the demand in this instance:
“As a Notified Body, NMi’s fundamental role is to ensure that the weight indicated by the machine – and the price consumers pay for a product – is as accurate and fair as possible. The first step is performing a conformity check on the devices to determine if the units perform to the manufacturer’s specification. This includes, among other things, a software test to determine if it is up-to-date and if the weight information is accurate and correctly displayed. NMi can also certify manufacturers to undertake their own initial verifications, according to a quality system, thereby saving time and money in the production process.
An important part of the conformity check is establishing whether a weighing instrument falls within the right maximum permissible error (MPE) category, which is a sure-fire method of guaranteeing its accuracy. To do this, we need to know the verification scale interval – or e value – which is the smallest interval that can be used to calculate the price based on weight in commercial transactions. In this instance, the e value is 2g, meaning that the scale is tested in increments of 2g. From 0g to 1kg the MPE is +/-1g, from 1kg to 4kg +/-2g, and 4kg to 6kg +/-3g.”
The Dutch government holds the right to conduct spot checks on the weighing instruments, and the supermarkets are responsible for keeping the scales accurate. Regular maintenance by the manufacturer prevents the machines from diverging, which is important for both consumer and seller. The addition of a tare function on the scales, which is what allows the customer to use their own packaging, also demands a level of trust, as the customer could fill up their container before weighing the ‘empty’ container, essentially giving them the product for free.
With the advent of both self-service shops and checkouts, as well as sustainable shopping experiences such as packaging-free shops, it's clear that metrology will expand as a servicing- and maintenance-based industry supporting the consumer market.