How to Calibrate & Troubleshoot the A&D EK-120i
- pete8781
- Jul 31
- 2 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-120i calibration uses an external 120 g default reference mass and should be followed by independent verification. MNM lists 0.01 g repeatability and ±0.01 g linearity, so environmental effects that are trivial on a 1 g scale can be important here. Leveling, static, airflow, temperature and pan contact should be checked before repeated calibration.
External calibration and verification
Use a suitable known 120 g reference on a stable, level balance. Center the mass, let the reading settle and complete the calibration procedure without touching the bench. Then remove it, confirm zero and verify another known value. A completed CAL routine is an adjustment; it does not replace evidence that the balance performs correctly across the real working range.
Static and airflow
Plastic containers, film and dry powders can create electrostatic force. If the displayed weight changes when a hand approaches the container, static is likely. Fans and HVAC can also move light samples. Improve the environment before recalibrating, because adjusting the balance while an external force is present only shifts the error.
Zero drift and eccentric loading
Check for debris beneath the pan, a container touching the housing, an uneven surface or temperature change. Compare a known test weight at the center and several representative pan positions if the application uses off-center loads. Large position effects point to mechanical setup rather than span calibration.
RS-232 troubleshooting
If the local display passes verification but the computer receives incorrect data, check serial settings, cable pinout and output mode separately. A communication problem is not a calibration problem. If both display and transmitted weight fail the same known-load check, investigate the weighing system first.
Frequently asked questions
What calibration mass does MNM list? 120 g. What are repeatability and linearity? 0.01 g and ±0.01 g. Should calibration be followed by verification? Yes. What commonly causes drift? Static, airflow, temperature, vibration or pan contact. What if only RS-232 data is wrong? Troubleshoot communications separately. Does calibration make EK-120i legal for trade? No; the exact model remains non-NTEP.
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