A&D FG-150KAL Calibration: CAL Switch Steps, 300 lb Weights and Gravity Setting

By MNM Scales · Last updated October 31, 2026

The A&D FG-150KAL is a 300 lb bench scale on a 15.4 x 20.9 inch platform, and like every FG-K model it calibrates with an external weight through a CAL switch inside the display pod. This guide follows A&D’s FG-K instruction manual step by step, adds tips from our TDA-registered technicians, and shows when to hand the job to us. For the keys and settings, see the FG-150KAL manual guide.

When the FG-150KAL needs calibration

• When the scale is first set up.
• After it has been moved, even across the building.
• When the room or environment changes, such as a move from an air-conditioned office to a dock.
• On a regular schedule; our how often should a scale be calibrated guide suggests intervals by use.
• When a known weight reads outside your tolerance.

What you need for FG-150KAL calibration

Item	Details
Test weight	300 lb or 150 kg is the factory value (full capacity). You can enter a smaller value; our technicians use certified weights at or near capacity so the whole range is checked.
Warm-up	At least 30 minutes powered on with nothing on the pan
Auto power-off	Set F1 to 0, or leave something on the pan during warm-up, so the scale stays on
Unit	lb or kg; calibration mode will not start in oz or pcs
Tool	A screwdriver for the lock screws; press the CAL switch with a fingertip, since A&D warns a ballpoint pen can short the board
Location	Calibrate where the scale will be used, level and on a solid surface

Weights in stacks are fine as long as the total matches the value on the display and every piece is certified. Our calibration weight classes guide explains which class suits a 300 lb bench scale, and we stock calibration weights.

FG-150KAL calibration step by step

1. Open the CAL switch. Loosen the lock screws on the rear of the display pod and remove the CAL switch cover. The calibration switch sits on the board inside.
2. Warm up the scale for at least 30 minutes with nothing on the pan, in lb or kg.
3. Enter calibration. Press and hold the CAL switch until Cal 0 appears, then release it.
4. Zero calibration. Make sure the pan is empty, wait for the STABLE indicator and press MODE. The scale stores zero and shows 5pn 1 with the span value, 300.00 in lb or 150.00 in kg.
5. Change the value if needed. To use a different weight, press ZERO to pick the blinking digit and PRINT to raise it until the display matches your weight.
6. Span calibration. Place the weight on the center of the pan, wait for STABLE and press MODE. end appears.
7. Finish. Remove the weight and turn the scale off. Refit the CAL switch cover and tighten the lock screws.

To stop after the zero calibration only, turn the power off at 5pn 1. A value you change in step 5 is cleared at power-off, so the next calibration starts again from 300 lb or 150 kg.

Checking the result

Turn the scale on, let it settle and place the test weight again; it should read the weight value. Check a load near half capacity and one near the low end of your range, and try the weight at each corner of the platform for an even reading. Our scale tolerance calculator shows acceptable error for your division size. If readings drift or will not return to zero, see scale will not zero or keeps drifting.

Gravity acceleration setting

Gravity varies by location, and the FG-K series stores a gravity value to match. A&D’s manual lets you change it when a weight is not on hand after a move: hold the CAL switch until Cal 0, press PRINT to show the stored value (for example 9.798), change it with ZERO and PRINT to the value for your area from the gravity map at the back of the manual, and press MODE to return to Cal 0; turn the power off to finish, or continue to a weight calibration.

A calibration with a weight at the place of use makes the gravity setting unnecessary, and our technicians calibrate the FG-150KAL with certified weights, on site or in our shop.

FG-150KAL calibration in Houston: our service options

If you do not keep 300 lb of certified weights on hand, or an auditor or customer asks for a certificate, MNM Scales calibrates the FG-150KAL in the 35 to 150 kg tier. Book through our scale calibration service in Houston:

Option	What you get	Price
In-house calibration	Calibrated with NIST-tested weights, certificate included	See the current rate on the listing
NIST calibration	Calibrated with a NIST-traceable certificate	See the current rate on the listing
On-site calibration	Our technicians come to you with test weights	$295 plus $2 per mile, round trip, once per visit, plus the per-scale rate

Mail-in works too: pack the scale in its original packing and use the mail-in calibration service, or drop it at our Cypress, TX shop by appointment. Our scale calibration cost guide and NIST vs in-house certificate guide help you choose.

Common calibration mistakes

• Skipping the 30-minute warm-up that A&D calls for before calibration.
• Starting in oz or pcs; switch to lb or kg first.
• Pressing MODE before STABLE lights, at zero or at span.
• Placing a weight that does not match the displayed value; the scale trusts the number on the display.
• Stacking weights off center or touching the column; keep the load on the middle of the platform.
• Calibrating in one room and using the scale in another.

Sealed scales used in trade

On the NTEP FG-150KALN, the CAL switch is sealed for commercial use: NTEP CC 05-101 describes a wire security seal through two thumb screws on the rear of the display. Keep that seal in place and call us; our legal-for-trade calibration service recalibrates commercial scales and places them in service in Texas. See our TDA scale certification guide and what is NTEP guide.

Texas note: TDA does not require an NTEP certificate for every device, but the scale must meet NIST Handbook 44 and suit its use; some scales do need one, so we recommend NTEP models and can check yours. See TDA’s scales used in trade guidance (PDF) and our TDA scale certification guide, or call us or TDA to confirm your use.

Frequently asked questions

How do I calibrate an A&D FG-150KAL?

Warm it up for 30 minutes, open the CAL switch cover on the rear of the display pod and hold the CAL switch until Cal 0 shows. With the pan empty press MODE, place the 300 lb (150 kg) weight or the value you set, and press MODE again. When end shows, remove the weight and turn the scale off.

Where is the CAL switch on the FG-150KAL?

On the board inside the display pod. Loosen the lock screws on the rear of the pod and remove the CAL switch cover to reach it. Press it with a fingertip, not a pen.

What weight do I need to calibrate the FG-150KAL?

The factory value is 300 lb or 150 kg, full capacity. You can enter a different value at the 5pn 1 step with ZERO and PRINT, and place a weight that matches it.

Why will my FG-150KAL not enter calibration mode?

The unit must be lb or kg. Switch away from oz or pcs with MODE, then hold the CAL switch until Cal 0 appears.

Do I need to set the gravity value?

Only if you cannot calibrate with a weight after a move. A calibration with a weight where the scale is used makes the gravity setting unnecessary.

How often should the FG-150KAL be calibrated?

On first setup, after every move, when the environment changes and on a regular schedule set by how heavily it is used and what your customers or auditors require.

Can MNM Scales calibrate my FG-150KAL?

Yes. It is in the 35 to 150 kg tier: in-house calibration with a certificate or NIST calibration with a NIST-traceable certificate (current rates on our calibration service page), by mail-in, drop-off in Cypress or on site. Call (832) 290-3120.