Weighbridge Load Cell Replacement: Signs, Matching and Step-by-Step Procedure

Quick answer: replace a weighbridge load cell when it fails a diagnostic test (drift that cannot be cleared, no signal, a broken or water-damaged cable, a cell that no longer returns to zero or shares load differently from its neighbours). To replace it correctly: confirm the cell is the fault, identify the exact type, capacity and output, fit a matched cell with the right mounting hardware, check the junction box and trim, recalibrate with test weights, and, if the weighbridge is used for trade, have it re-verified by a licensed person. Never swap in a cell of a different type without checking that the weighbridge approval allows it. This guide walks through the process step by step, with the mistakes that cause repeat failures, and tells you what to send us for a match.

Signs a weighbridge load cell may need replacing

Always confirm the fault before buying, because many weighbridge problems are in the cable, junction box, mount or platform, not in the cell. See how to test a load cell with a multimeter and load cell troubleshooting. For the repair-or-replace decision, read repair or replace.

Step 1: Make sure the cell is the problem

1. Visually inspect the cell, the cable and the junction box. Look for water, corrosion, crushed cable and burnt terminals.
2. Check the mechanical side: debris under the deck, a loose or binding check rod, worn mounting hardware, and a deck that is not sitting evenly.
3. Test each cell’s bridge resistance and zero output as described in the testing guide.
4. If the cell passes but readings are wrong, suspect the junction box, trim, indicator or mechanics.

Step 2: Identify the cell

Record everything on the nameplate and cable tag: brand, model, serial number, capacity, output in mV/V, input and output resistance, and cable length. Note whether it is a column (compression) cell or a double-ended shear beam, and whether the weighbridge has digital or analogue cells. Photograph the cell in place, with the mount. Our model guide, load cell brands and models explained, shows how to read model numbers.

Typical weighbridge cells in our range include:

• Revere ASC2 (30, 40 and 50 t, stainless steel, hermetically sealed, built-in surge protection).
• Tedea-Huntleigh Model 120 (3 to 50 t, stainless steel, surge arrestors, 6-wire sense circuit).
• Revere 5223 and Sensortronics 65040W double-ended shear beams.
• Mounting assemblies such as the Revere ASC-DSC.

Step 3: Match the replacement

The ASC2 is described as compatible with the original ASC, and offers current calibration output to ease parallel calibration of multiple cells. These details are exactly the kind of fact to check on the datasheet. For cross-referencing, see buying load cells in Australia.

Step 4: Replace one cell or all?

If one cell has failed, replacing only that cell is common and usually fine, provided the new cell is matched in capacity and output to the others. Replace all cells together if:

• The cells are old and others are showing drift or moisture.
• The original model is obsolete and no matched cell is available.
• The weighbridge has had a lightning strike or flood that may have stressed several cells.
• The cost of repeated downtime outweighs the cost of a full set.

Step 5: The replacement procedure

Follow the weighbridge maker’s procedure. In outline:

1. Plan and isolate: arrange traffic management, lockout the electrical supply, and note that the platform will need to be lifted or supported.
2. Record: mark and photograph cable routes and the junction box terminals.
3. Lift or support the deck using the method and equipment specified for the weighbridge, with qualified people.
4. Remove the old cell, noting the orientation and the mounting parts.
5. Inspect the base, cap and check rods for wear and corrosion. Replace worn parts, because a new cell on a worn mount will perform poorly.
6. Fit the new cell in the same orientation, with the load applied through the centre. Use the correct torque and, where specified, self-aligning mounts.
7. Connect the cable to the junction box using the colour code in the datasheet. Seal the cable entry.
8. Lower the deck and check there is free movement and no binding.
9. Check zero and corner balance with a known weight at each cell position.
10. Recalibrate with certified test weights.

Weighbridge decks are very heavy, so this work carries real risk. Use competent contractors and follow safe work procedures.

Step 6: Corner trim and calibration

Each cell has a slightly different output. After replacement the junction box is trimmed so that a test weight gives the same reading wherever it sits on the deck. Then the system is calibrated with test weights across its range. See load cell calibration and load cell installation.

Step 7: Trade re-verification

If the weighbridge is used for trade, repairs usually require checking and certification by a licensed person before it returns to use. Confirm the exact requirement with the National Measurement Institute or your licensed provider. See trade approved weighbridges and legal for trade weighing.

Reducing the chance of repeat failures

• Fix the cause: if water or lightning killed the cell, improve drainage, sealing and surge protection.
• Use sealed cells: hermetic stainless cells last longer in wet pits.
• Keep the pit clean: debris causes binding and corrosion.
• Protect cabling: use conduit and drip loops, and seal entries.
• Check regularly: log the zero and corner readings, and investigate shifts early.
• Hold a spare: a matched spare cell shortens downtime.

What to send us for a replacement match

1. A photo of the nameplate and cable tag.
2. Brand, model, serial number, capacity and output.
3. The weighbridge make, model and year if known, and whether it is trade approved.
4. A photo of the mounting arrangement.
5. The number of cells and whether others are original.
6. Your site, deadline and any approvals required.

Send these through the contact page. We will tell you honestly what we can supply and what is uncertain.

Worked example: a grain depot after a storm

A grain depot’s weighbridge reads 80 kg high at one corner and drifts upward after rain. The operator inspects the junction box and finds water and corroded terminals. The cell tests normally once the box is dried, but the cable entry is cracked. Fixing the cable gland and drying the box solves the drift, so the cell is not replaced. Two months later a lightning strike kills another cell, and a matched replacement is fitted, trimmed and re-verified. The depot then adds surge protection and improves pit drainage. The first fault was cheap to fix because the diagnosis came before the purchase.

A printable checklist

1. Fault confirmed on the cell (resistance, zero, load, insulation).
2. Cell data recorded: brand, model, serial, capacity, output.
3. Replacement matched and datasheet checked.
4. Mounting parts inspected and replaced if worn.
5. Deck lifted and supported safely.
6. New cell fitted, cable sealed and connected to the correct terminals.
7. Corner trim done and calibration completed.
8. Trade re-verification arranged if required.
9. Cause of failure addressed (drainage, sealing, surge protection).
10. Records updated and a spare ordered.

Frequently asked questions

How long does a weighbridge load cell last?

It depends on the cell, the environment and how well the weighbridge is protected. Sealed stainless cells in well-drained installations last longest.

Can I replace a cell without recalibrating?

No. Recalibration and corner trim are needed, and trade weighbridges need re-verification.

Can I mix old and new cells?

Often yes, if outputs are matched. Check with the maker.

What if my cell model is obsolete?

Send us the details, and we will look for a current model that fits. A full set may be the better option.

Do you supply cells for weighbridges?

Yes. See the canister load cells and double ended shear beams.

Next steps

Read weighbridge load cells and weighing for mining.