Chain Of Custody Calculator

Verify every handoff for construction materials and samples. Spot gaps before audits or claims start. Export reports instantly for supervisors, labs, and clients now.

Custody Entry Form

Use the fields below to compute gaps, signatures, and integrity scoring.

Sample Details


Transfer Log

Add each handoff in chronological order for best results.
# From To Date/Time Location Seal New Seal Condition Reason/Notes Released Signature Received Signature
1
2

Closeout Time (Optional)

Use when the sample is disposed or testing concludes.

Integrity Scoring Settings

Gaps above this threshold are flagged and penalized.
Scores below this should be reviewed before acceptance.
Penalty Weights
Tune scoring to match your QA/QC policy.
Fields marked with an asterisk are required for complete scoring.

Example Data Table

This table illustrates a typical custody flow from site collection to laboratory receipt.
# From To Date/Time Location Seal Condition Released Sig Received Sig
1 Field Tech A Site QA Store 2026-01-30 10:30 Gate Store Room Unchanged Intact FTA SQS
2 Site QA Store Courier Service 2026-01-30 15:00 Dispatch Bay Unchanged Good SQS CS
3 Courier Service Lab Receiving 2026-01-31 09:10 Lab A Front Desk Unchanged Intact CS LR

Formula Used

Custody duration (hours): (Last timestamp - Collection timestamp) / 3600.

Transfer gap (hours): (Current transfer time - previous custody time) / 3600.

Integrity score: Start at 100, then subtract penalties for each issue:

How to Use This Calculator

  1. Enter project, sample ID, collector, collection time, location, and seal.
  2. Add each transfer row in the order it happened.
  3. Fill from/to parties, timestamps, locations, and both signatures.
  4. Mark seal changes and record the new seal plus reason.
  5. Adjust gap threshold and penalty weights to match your policy.
  6. Press Submit to view results above the form instantly.
  7. Download CSV or PDF to attach to QA/QC records.

Field-to-Lab Traceability Benchmarks

Construction QA/QC programs often rely on third-party testing, and custody documentation is the fastest way to defend results. A typical concrete cylinder or soil sample may pass through 3–6 hands in 24–48 hours. This calculator quantifies the time gaps between transfers and highlights missing signatures so you can correct the record before submittal.

Transfer Gap Risk Indicators

Long, undocumented gaps raise questions about storage control, temperature exposure, and tampering. Many sites use an internal threshold such as 8–24 hours depending on sample sensitivity and courier schedules. Enter your allowed gap value to flag any segment that exceeds the threshold and apply a consistent penalty for each breach.

Seal and Condition Exception Tracking

Seal changes are not always failures, but they must be justified. Repackaging after breakage, splitting samples, or lab receipt procedures should be recorded with a new seal number and a reason. Condition notes like “Damaged” or “Wet” are treated as integrity risks, prompting review before acceptance or dispute resolution.

Integrity Scoring for Review Workflow

The scoring model starts at 100 and subtracts configured penalties for missing required fields, gap exceedances, seal changes, poor condition entries, and time-order problems. Supervisors can set a pass threshold, for example 80/100, to route low-scoring chains to corrective action, retesting, or formal nonconformance logs.

Example Data Snapshot

The following example reflects a common three-step path from site collection to laboratory receiving. Use it as a template for your own log entries.

#FromToDate/TimeLocationSealConditionReleasedReceived
1Field Tech ASite QA Store2026-01-30 10:30Gate Store RoomUnchangedIntactFTASQS
2Site QA StoreCourier Service2026-01-30 15:00Dispatch BayUnchangedGoodSQSCS
3Courier ServiceLab Receiving2026-01-31 09:10Lab A Front DeskUnchangedIntactCSLR

FAQs

1) What should I enter as the “Allowed Gap”?

Use your QA/QC policy or testing requirements. Many teams start with 12–24 hours for routine samples and tighten it for sensitive materials, long transport routes, or strict owner specifications.

2) Does a seal change automatically mean the sample is invalid?

Not always. A seal change can be acceptable if it is documented with a new seal number, a clear reason, and uninterrupted signatures. The calculator flags it so reviewers confirm the justification.

3) Why are signatures required for each transfer?

Signatures demonstrate accountability at the handoff point. Missing release or receipt signatures create uncertainty about control and can weaken claims support or test result defensibility.

4) What happens if transfer times are entered out of order?

The calculator applies an order penalty and may flag negative gaps. Re-enter times in the sequence they occurred to produce an accurate timeline and holder-duration totals.

5) Can I use this for materials other than lab samples?

Yes. It works for custody of any controlled item: rebar coupons, weld coupons, asphalt cores, controlled documents, or high-value components, as long as you can record handoffs and timestamps.

6) What does the PASS/REVIEW status mean?

PASS means the score meets your threshold and no sequence problems were detected. REVIEW suggests gaps, missing fields, seal/condition issues, or time-order problems that should be checked before acceptance.

7) Do CSV and PDF exports include all issues?

Yes. On-screen lists are limited for readability, but exports include the full summary, scoring settings, transfer rows, timeline segments, holder totals, and all detected issues for recordkeeping.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.