How to Calibrate, Verify & Maintain the A&D EK-12Ki NTEP Class II Balance
- pete8781
- Jul 31
- 3 min read
Need more details or help choosing the correct item? Call MNM Scales at (832) 290-3120 or email mnmscales@yahoo.com.
A&D EK-12Ki calibration, verification and maintenance must account for both its 12 kg capacity and NTEP Class II legal-for-trade status. The balance uses external calibration, and MNM lists a 12 kg default calibration mass. For internal process use, calibration can follow the facility’s quality SOP. For a scale already placed in commercial service, routine users should preserve approved metrological controls, perform known-weight verification without unnecessary adjustment, and use qualified service when protected calibration needs to change.
Stable installation matters at 12 kg
A 12 kg load can reveal bench flex, uneven feet and pan contact that are invisible at a few hundred grams. Level the balance on a rigid surface and make sure containers do not touch walls, guards or cables. Allow the scale and reference weights to reach the operating temperature. Before calibration, confirm that the entire gross load will sit safely on the compact 133 × 170 mm pan without secondary support.
External calibration with a 12 kg reference
For a unit where user calibration is appropriate, use a suitable known 12 kg mass and the EK-i external calibration procedure. Center the reference and avoid touching the table while the point is captured. A high-capacity calibration mass must be handled safely and its metrological status should match the quality requirement. After adjustment, remove it and confirm zero before independent verification.
Class II commercial verification
For legal-for-trade operation, use known test weights and the applicable local inspection/service procedure to verify the device without casually changing protected settings. A&D identifies EK-12Ki as NTEP Class II, but state/local rules govern how it is placed and maintained in service. If routine verification fails, rule out reference-weight, installation, power and load-contact problems before arranging qualified adjustment and any required reinspection.
Multi-point and corner checks
A station used from 1 kg to 12 kg should be checked at meaningful points across that range rather than only at full capacity. Repeat a known load to evaluate consistency and move a suitable test load among representative pan positions to screen for eccentric-loading problems. If position changes the result materially, inspect leveling, pan seating and mechanical contact rather than trying to calibrate around the fault.
Underhook verification
When using EKW-07i underhook, inspect the fixture and verify known loads in the suspended configuration. A hook, wire or sample touching the floor, bench or housing bypasses the weighing system and can produce a false result. Also confirm the fixture’s safe working load; the balance’s 12 kg capacity is not automatically a rating for every accessory component.
Power and RS-232 troubleshooting
If the display becomes unstable, check power, environment and mechanical contact before calibration. If the local display passes known-weight checks but PC or printer data is wrong, isolate the RS-232 cable/settings and record format. Communications problems should not cause a metrological adjustment. The optional rechargeable battery should also be checked before diagnosing intermittent power behavior.
When to remove EK-12Ki from commercial service
Stop using the balance for regulated transactions after repeated failed verification, severe impact/overload, visible mechanical damage or evidence that required metrological controls have been compromised. Mark the device so another employee does not continue transactions, arrange qualified service and follow the local process for returning it to legal use.
Frequently asked questions
What default calibration mass does MNM list? 12 kg. Is EK-12Ki external calibration? Yes. Is it NTEP Class II? Yes according to A&D U.S. Should a legal-for-trade operator recalibrate it casually? No; use verification and qualified service/local procedures. Should a 12 kg-range balance be checked at multiple weights? Yes. Can the underhook setup be verified separately? Yes and it should be. What if RS-232 data fails but the local weight is correct? Troubleshoot the data path, not calibration. When should commercial use stop? After repeated failed verification or significant damage/control issues.
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