Maintenance & Reliability · PM Log

Shipping Scale Tare Weight Calibration Verification

Preventive maintenance log for verifying that floor, platform, and bench scales used in shipping and receiving display accurate tare weight readings. Ensures correct billable weights, inventory integrity, and compliance with Measurement Canada trade requirements.

Estimated Time

30 min

Difficulty

Intermediate

Regulation

Measurement Canada

Version

1.0

Free download — no sign‑up, no email.Take this PM log to your shipping dock and start verifying today.

↓ PDF (print‑ready) ↓ Word (editable)

Purpose

This preventive maintenance (PM) log establishes a repeatable procedure to verify that the tare weight calibration of shipping scales is within the acceptable tolerance of ±0.1% of full-scale capacity. Accurate tare weight ensures that customers are billed correctly, carrier chargebacks are minimized, and inventory records reflect true net weights. Regular verification also satisfies the periodic inspection requirements for trade-approved scales under Measurement Canada specification S-S-01.

Scope

Applies to all floor scales (e.g., 500–10,000 lb capacity), platform scales (e.g., 100–500 lb capacity), and bench scales (e.g., 10–100 lb capacity) used for outbound and inbound shipping weighing at this facility. This log covers the quarterly tare calibration verification. It does not cover full-span recalibration, load cell replacement, or scale hardware removal; those activities require a separate work order and certified calibration provider.

Safety Precautions

LOTOLockout/tagout the scale's electrical supply before cleaning or inspecting the load cell area. Confirm zero energy state with a multimeter at the disconnect.
ERGOUse a hand truck or cart to transport all test weights. Certified calibration weights can exceed 50 lb each — do not lift manually. Use two-person lift for any stack exceeding 75 lb total.
SLIPKeep the weigh platform and surrounding floor area dry and free of debris. Wipe up any grease, oil, or water immediately before placing test weights.
PPEWear Class 1 high-visibility vest, steel-toed boots, and impact-resistant gloves when working on the shipping dock near forklift traffic.

Required Tools & Materials

Certified test weight set — NIST-traceable, Class F or better, covering 25%, 50%, 75%, and 100% of scale rated capacity
Scale calibration log sheet (paper or digital form in ServiceGrid)
Lint-free cloth (microfibre) and isopropyl alcohol wipes
Small bubble level (machinist-grade, 0.0005 in/in sensitivity)
Calibration sticker and "DO NOT USE" tags (red)
Hand truck or flatbed cart for weight transport
ServiceGrid CMMS mobile device (optional, for digital record-keeping)

Stop Chasing Maintenance Blindly

Track every calibration, pressure drop reading, and machine performance trend in one place. ServiceGrid logs your tasks automatically and alerts you before failure.

Try ServiceGrid →

Procedure: Step-by-Step

1 Lockout/Tagout and Clean the Scale. Apply LOTO to the scale's main power disconnect. Remove any debris, dust, or product residue from the weigh platform and the gap around the load cell using the lint-free cloth. Place the bubble level on the centre of the platform. Adjust the four leveling feet until the bubble is centred within the bullseye — no more than 1/2 graduation off centre. Document the platform condition on the log sheet.

2 Verify Test Weight Certification. Inspect the calibration sticker on each test weight. Confirm the NIST-traceable certificate is current (not expired). Record the weight ID number, nominal mass (e.g., 50 lb), and certification expiry date on the log sheet. Any weight with a damaged or expired sticker must be quarantined and replaced before proceeding.

3 Power Up and Allow Warm-Up. Remove LOTO. Restore power to the scale. Allow the indicator to complete its self-test sequence and enter weigh mode. Wait a full 10 minutes for the load cell and electronics to thermally stabilize. The display should read 0.000 — if any error code (e.g., E03, OL, or unstable symbol) persists, stop and file a ServiceGrid work order for scale repair.

4 Tare the Empty Scale. With the platform completely empty, press the TARE or ZERO button. Confirm the display reads 0.000 ±0.001 of full scale capacity. Observe for 30 seconds — if the reading drifts more than 0.002, clean the load cell area again and re-tare. If drift continues, flag the scale for calibration service.

5 Perform Multiple Test Weight Placements (Corner Load Test). Using the test weight set that equals 25% of the scale's rated capacity, place the weight in these five positions in order: (a) centre, (b) front-left corner, (c) front-right corner, (d) back-left corner, (e) back-right corner. Wait 5 seconds after each placement for the reading to settle. Record the displayed weight for each position. Repeat the entire sequence using test weights at 50%, 75%, and 100% rated capacity.

6 Calculate and Evaluate Deviation. For each of the 20 measurement points (5 positions × 4 capacities), compute the deviation: displayed weight − nominal test weight. The acceptable tolerance is ±0.1% of the test weight value for trade-approved scales. Example: a 50 lb test weight must read between 49.95 lb and 50.05 lb. Circle any point that exceeds tolerance and mark the corner location with a red marker on the log.

7 Return-to-Zero Check. Remove all test weights from the platform. Wait 10 seconds. Confirm the display returns to 0.000 ±0.001. If the return-to-zero drift exceeds 0.002, the scale must not be returned to service until a certified metrologist performs a full recalibration.

8 Final Status and Documentation. Mark PASS or FAIL clearly on the calibration log. If all 20 points are within tolerance: affix the new calibration sticker with technician initials and date. If any point failed: attach a red DO NOT USE tag over the indicator display and submit a Priority maintenance request in ServiceGrid. Scan the completed log sheet (or attach a photo in the ServiceGrid task) and file it to the scale's asset record.

Shipping Scale Tare Weight Calibration Verification

Stop Chasing Maintenance Blindly

Software that works like your best tools.