OIML tolerances

What is OIML?

In the "International Organization of Legal Metrology" work representatives of 100 states for uniform construction and testing of all instruments. In the certification system of OIML the certificates issued by the member states attest that a specific measuring equipment type matches the OIML recommendations. So a construction tested and approved in one country can be approved in another country without repeating the examination.
The OIML guidelines specify maximum design characteristics for test standards define how material, surface texture, markings, construction, form, etc.

OIML error Limits according to OIML R 111

Error limits (tolerance ±)
E1 E2 F1 F2 M1 M2 M3
1 mg ±0.003mg ±0.006mg ±0.020mg ±0.06mg ±0.20mg    
2 mg ±0.003mg ±0.006mg ±0.020mg ±0.06mg ±0.20mg    
5 mg ±0.003mg ±0.006mg ±0.020mg ±0.06mg ±0.02mg    
10 mg ±0.003mg ±0.008mg ±0.025mg ±0.08mg ±0.25mg    
20 mg ±0.003mg ±0.010mg ±0.03mg ±0.10mg ±0.3mg    
50 mg ±0.004mg ±0.012mg ±0.04mg ±0.12mg ±0.4mg    
100 mg ±0.005mg ±0.016mg ±0.05mg ±0.16mg ±0.5mg ±1.6mg  
200 mg ±0.006mg ±0.020mg ±0.06mg ±0.20mg ±0.6mg ±2.0mg  
500 mg ±0.008mg ±0.025mg ±0.08mg ±0.25mg ±0.8mg ±2.5mg  
1 g ±0.010mg ±0.03mg ±0.10mg ±0.3mg ±1.0mg ±3.0mg ±10mg
2 g ±0.012mg ±0.04mg ±0.12mg ±0.4mg ±1.2mg ±4.0mg ±12mg
5 g ±0.016mg ±0.05mg ±0.16mg ±0.5mg ±1.6mg ±5.0mg ±16mg
10 g ±0.020mg ±0.06mg ±0.20mg ±0.6mg ±2.0mg ±6.0mg ±20mg
20 g ±0.025mg ±0.08mg ±0.25mg ±0.8mg ±2.5mg ±8.0mg ±25mg
50 g ±0.03mg ±0.10mg ±0.3mg ±1.0mg ±3.0mg ±10mg ±30mg
100 g ±0.05mg ±0.16mg ±0.5mg ±1.6mg ±5.0mg ±16mg ±50mg
200 g ±0.10 mg ±0.3mg ±1.0mg ±3.0mg ±10mg ±30mg ±100mg
500 g ±0.25mg ±0.8mg ±2.5mg ±8.0mg ±25mg ±80mg ±250mg
1 kg ±0.5mg ±1.6mg ±5.0mg ±16mg ±50mg ±160mg ±500mg
2 kg ±1.0mg ±3.0mg ±10mg ±30mg ±100mg ±300mg ±1,0g
5 kg ±2.5mg ±8.0mg ±25mg ±80mg ±250mg ±800mg ±2,5g
10 kg ±5.0mg ±16mg ±50mg ±160mg ±500mg ±1600mg ±5,0g
20 kg ±10mg ±30mg ±100mg ±300mg ±1000mg ±3000mg ±10g
50 kg ±25mg ±80mg ±250mg ±800mg ±2500mg ±8000mg ±25g
100 kg   ±160mg ±500mg ±1600mg ±5000mg ±16g ±50g
200 kg   ±300mg ±1000mg ±3000mg ±10g ±30g ±100g
500 kg   ±800mg ±2500mg ±8000mg ±25g ±80g ±250g
1000 kg   ±1600mg ±5000mg ±16g ±50g ±160g ±500g
2000 kg     ±10g ±30g ±100g ±300g ±1000g
5000 kg     ±25g ±80g ±250g ±800g ±2500g


As test weights to in-plant control of precision balances KERN also offers NON-OIML weights that do not meet the above mentioned requirements. They can also be used for DAkkS calibrations, but no accuracy class is recorded on the calibration certificate.

NON-OIML weights are not admitted for verification.