CALIBRATION WEIGHTS GUIDE
Very hard wearing and resistant to knocks and scratches
Suitable for Warehouse & Industrial environments where rough handling is likely.
Can be easily recalibrated by a Metrology / UKAS Accredited test house.
Can be supplied to a good levels of accuracy and UKAS M1 Accredited.
Can be shot blast, repainted and recalibrated.
The most effective option.
Providing they are lead free, they can be easily recycled.
Will rust over time especially if allowed to get wet.
Limited to M1 accuracy.
Very hard wearing and resistant to light knocks and scratches but due to the level of accuracy, this should be avoided.
Suitable for precision retail scales and laboratory balances with a resolution in the region 0.1g.
Can be supplied to a very high level of accuracy and UKAS M1 Accredited.
Must be handled very carefully due to the level of accuracy. These weights are typically calibrated to M1, F1, E2 and E1
Can't always be recalibrated by a Metrology / UKAS Accredited test house.
In the case of F1 and upwards, they are the most expensive option.
The M Class specification for weights is divided into 3 Classes. M1, M2 & M3 with M1 being the most accurate and the favoured specification. Examples:
M1 weights would be used for a retail scale with a resolution of 20kg x +/- 0.5g
M3 weights are for scales with a lower resolution, for example, a Postal Scale that reads to 50kg x +/- 1 gram.
M Class weights are available in Cast Iron and Brass and easy to recalibrate and keep in service.
The F Class specification for weights is divided into 2 Classes. F1 and F2 with F1 being the most accurate. F Class weights are the specification for scales with a very high resolution, for example, a Laboratory Balance that reads to 6kg x +/- 0.1 gram.
F Class weights are available only in Stainless Steel and are often supplied with some kind of certification, generally UKAS.
The E Class specification for weights is divided into 3 Classes. E0, E1 and E2 with E0 being the most accurate. E Class weights are for scales with an extremely high resolution, for example, a Laboratory balance that reads to 220g x +/- 0.1mg. E1 Class weights are often used as a National Standard.
E Class weights are available only in Stainless Steel and are nearly always supplied with an Internationally recognised Certificated of Accreditation be it DaKKs or UKAS.
LEAD FREE WEIGHTS - WHY IT'S SO IMPORTANT
CANNOT BE RECYCLED
Lead is a contaminant that causes MAJOR problems in iron recycling systems.
Depending on which list you refer to lead is always a highly ranked, toxic metals. In the US its ranked the 2nd most poisonous metals.
Melting Lead scrap is energy intensive. Once hammered into a weight both the lead and iron cannot be recycled without more energy consumption heating up the lead in an attamept to extract it.