Here in the UK, we have adopted the standard BS EN 60335-2-25:2002 for Household Electrical Appliances (with reference to microwave ovens) and BS EN 60335-2-90:2006 for Commercial Microwave ovens, in respect of the maximum amount of microwave energy permitted to leak from a microwave oven. In both of the above documents, the maximum permitted leakage is set at 5mW/cm2, measured at distance of 5cm from the potential leakage source.
Even if a leak is discovered that falls below the required standard, it still makes sense to investigate further and possibly take preventative action, since leaks of this nature are unlikely to improve over time.
National Standard Calibrated Instruments
The accurate measurement of energy leakage, or “microwave power flux density” as it is termed, requires specialist professional instruments, accurately calibrated to UK National Standards. With the growth in popularity of microwave ovens over the last few decades, demand for these microwave test instruments has increased too. Unfortunately, this has led to a rise in the number and use of microwave instruments that claim a level of accuracy that they fail to achieve.
However, despite the provision of specific standards for microwave leakage, set out in the above documents there is no UK standard for the specification of instruments that may be used to determine if a microwave oven is within the stated UK leaakage standard.
The reason for this anomaly is that BS5175 (1976), which contained a specification for this type of instrument was replaced by the above documents that contain no such instrument specification.
Thus, customers whose microwave ovens are tested as part of a maintenance programme are advised to ask the user of the instrument if that instrument has an in-date calibration certificate Traceable to UK National Standards, as this is their guarantee that the data provided by the test instrument can be relied upon.
Celtek Electronics Ltd supplies instruments that have been calibrated to the required specifications and the calibration equipment is regularly checked to ensure performance standards are maintained.
To view our range of microwave safety products please click here or contact us with any enquiries.