How to Calibrate the A&D EK-1200i: Step-by-Step Guide (Plus Calibration Test and Error Codes)

The A&D EK-1200i is one of the most popular counter balances for jewelers, gold buyers, pawn shops, schools and shipping desks: 1200 g × 0.1 g, NTEP Class II, with ±0.1 g linearity. It holds calibration well, but A&D says to calibrate it when it’s first used, after it’s moved, when the environment changes, and on a regular schedule. This guide walks through each step from the A&D EK-i manual, plus the calibration test, the gravity setting and what the error codes mean.

What you need

• A calibration weight. The EK-1200i is set at the factory to calibrate with 1200 g. You can enter a different weight value (step 4 below), but the closer the weight is to full capacity, the better the span. Use a certified weight of the right class (see calibration weight classes explained) and browse our calibration weights. A calibration weight is not included with the balance.
• A stable spot. A solid, level table away from drafts, vents, direct sun and vibration. Level the balance with the feet until the bubble is centered.
• Warm-up time. At least 30 minutes powered on with nothing on the pan.
• Access to the CAL switch. On the EK-i series it’s a push-button on the back of the balance, behind a small access plate.

Step-by-step: calibrating the EK-1200i with a weight

1. Warm up. Turn the balance on and let it warm up for at least half an hour with nothing on the pan.
2. Enter calibration. Press and hold the CAL switch until Cal appears, then release it.
3. Cal 0. The display shows Cal 0. To use the weight value already stored (1200 g from the factory), go to step 5. To use a different weight, go to step 4.
4. Change the weight value (optional). Press SAMPLE. The display shows the stored calibration weight in grams (for example 01200.0). Press SAMPLE to pick the blinking digit and RE-ZERO to change it. Press PRINT to store the value (or MODE to cancel). You’re back at Cal 0. The value stays in memory after the balance is switched off.
5. Set zero. With the pan empty, press PRINT. The balance weighs the zero point. Don’t touch the pan or the table.
6. Set span. When the display shows the weight value, place the calibration weight in the center of the pan and press PRINT. Again, hands off while it weighs.
7. Finish. end appears. Remove the weight and press the CAL switch or MODE to return to weighing.

Check your work: re-zero, place the weight back on the pan and confirm the reading. Then try a weight around half capacity, such as a 500 g Class I calibration weight (not included), to confirm the balance reads correctly in the middle of the range. The EK-1200i’s specified linearity is ±0.1 g.

CAL error codes and what to do

Display	Meaning	What to do
Cal e	Calibration canceled: the weight is too heavy for the value set.	Check that the weight matches the value in step 4 and that nothing else is touching the pan. Press MODE and start again.
-Cal e	Calibration canceled: the weight is too light for the value set.	Check the weight value and the pan. Press MODE and start again.
error1	Stability error: the reading won’t settle.	Move away from drafts and vibration, then press MODE.
e	Overload: more than capacity is on the pan.	Remove the load.
lb0	Battery pack low (optional OP-09 / EKW-09i battery, not included).	Recharge it or use the AC adapter. Don’t calibrate on a low battery.

If an error keeps coming back with a known-good weight, the balance may need service. Contact us and we’ll take a look.

Calibration test: check accuracy without changing anything

The calibration test (CC) compares the balance against a weight without re-adjusting it. It’s the right tool for routine checks and for GLP records.

1. Press and hold the CAL switch. CC appears after Cal. Release the switch when CC is shown.
2. CC 0 is displayed. To change the test weight value, press SAMPLE and use SAMPLE (digit) and RE-ZERO (value), then PRINT to store.
3. Press PRINT with the pan empty. The zero point is weighed and shown for a few seconds.
4. Place the test weight on the pan and press PRINT. The weighed value is shown for a few seconds, then end.
5. Remove the weight and press MODE to return to weighing.

GLP printouts: with the function setting info at 1 or 2, the balance outputs a calibration report (after a calibration) or a calibration test report (after a CC test) through its RS-232C port to a printer or PC. The report includes the balance ID and serial number.

No weight handy? The gravity acceleration setting

Gravity changes slightly from place to place, so a balance calibrated in one city reads a little differently in another. If you move the EK-1200i and can’t calibrate it with a weight right away, A&D lets you enter the local gravity value instead:

1. Press and hold CAL until Cal appears, then release.
2. At Cal 0, press RE-ZERO. The stored gravity value appears (for example 9.7980).
3. Use SAMPLE (digit) and RE-ZERO (value) to enter your local value, then press PRINT.
4. Press MODE to finish. end appears and the balance returns to weighing.

The manual’s gravity map lists, for example, 9.796 m/s² for Los Angeles, 9.800 for San Francisco, 9.801 for Washington DC, 9.802 for New York and 9.803 for Chicago. This is a stopgap. A&D’s note is clear that calibrating with a weight where the balance is used is the better option, and then no gravity correction is needed.

How often to calibrate an EK-1200i

• Always: when it’s first set up, after it’s moved and when the room changes (temperature, new bench).
• Routine checks: a quick check with a test weight at the start of the day or week, depending on how much you rely on it.
• Certified calibration: most businesses schedule a certified calibration at least once a year, and more often for legal-for-trade, pharmacy or QC work, or when an auditor sets the interval.

Let MNM Scales calibrate it for you

The EK-1200i (1.2 kg maximum capacity) is in our up to 2.2 kg calibration tier. Mail it in and we’ll calibrate it in our Texas shop, usually within 1 to 3 business days, and ship it back with a certificate. Mail-in TDA and NIST calibration is available nationwide. Across the Houston area we also calibrate on-site ($295 service call plus $2 per mile round trip), which is handy when you have several scales at one location.

Why buy and calibrate with MNM Scales

MNM Scales has been in business for over 30 years and is one of the largest scale distributors in the country, with one of the largest selections of A&D balances and authorized-dealer support. We stock the EK-1200i in Texas, ship fast, and the same team that sells your balance calibrates and repairs it. For lab-grade milligram balances, see our FX-120i calibration guide.

Frequently asked questions

How do I calibrate an A&D EK-1200i?

Warm it up for at least 30 minutes with the pan empty. Press and hold the CAL switch until Cal appears and release it. At Cal 0, press PRINT to set zero, place the calibration weight (1200 g from the factory) on the pan and press PRINT. When end appears, remove the weight and press MODE.

What weight do I need to calibrate the EK-1200i?

The factory setting is 1200 g. You can enter a different weight value at the Cal 0 step by pressing SAMPLE, but a weight close to full capacity gives the best result. A calibration weight is not included with the balance.

Where is the CAL switch on the EK-1200i?

On the EK-i series the CAL push-button is on the back of the balance, behind a small access plate. On legal-for-trade units that plate can be wire-sealed.

What do Cal e and -Cal e mean on an EK-1200i?

Cal e means calibration was canceled because the weight was too heavy for the value set. -Cal e means it was too light. Check the weight value and the pan, press MODE and try again.

Can I calibrate the EK-1200i without a weight?

You can enter the local gravity acceleration value at Cal 0 by pressing RE-ZERO. It compensates for a move, but calibrating with a weight where the balance is used is more accurate.

How much does it cost to calibrate an EK-1200i?

At MNM Scales the EK-1200i is in the up to 2.2 kg tier: $95 for in-house calibration with a certificate or $395 for NIST calibration with a NIST-traceable certificate. Mail-in usually takes 1 to 3 business days.