In 2018, The UK food regulator has found some evidence of hygiene law breaches at 2 Sisters Food Group, the country’s biggest supplier of poultry to supermarkets. This highlights the need to comply with requirements on food safety/hygiene testing. The food safety testing market is a niche industry and for years, the technology has not seen any major breakthrough. But not any more, a German start-up has found a way of re-inventing the food safety test machine and this is a very promising technology.

They have machines ready to distribute to some major food industry players, but first, they need to pass the EMC regulations so that they can have the CE marking on their final products.

Project: Troubleshooting radiated emissions of a food safety testing machine

Timescale: A two-day workshop at our premises with a client’s engineer

Scope of work: A large size machine has experienced several EMI issues including radiated emissions, ESD

The product is a mains powered machine used for food safety industry. It is a novel machine which has the potential to disrupt the market. Therefore, all information about this product is highly sensitive.

The large equipment was shipped to our office before the troubleshooting work. The machine is placed in this large box, it weighs about 100 kg.

The DUT is large and heavy, it is being security checked by our COO

Since the machine suffers radiated emissions at lower frequency end. A large biconical antenna was set up at approximately 3 meters away from the unit. We had this antenna results as our far field measurement results while we were working on the unit using near-field troubleshooting approaches. See below:

Our troubleshooting set-up, with both far field and near field measurement tools

By targeting each problematic spectrum, we used step by step approach to suppress the noise, see results below. 10 dB reduction at point 1 and 2.

The lower frequency performance was improved by applying some filters.