A group session records genuinely shared work once while keeping a separate calibration event, result, approval and any required certificate for each selected equipment requirement. Ready devices can be submitted without selecting incomplete devices. Recording shared work still follows the approved step sequence for the participating devices.
For example, thirty sensors can share an actual bath reference observation while each sensor retains its own indication at each approved point. Use the group session for shared work and the readings grid; use the linked individual event pages for each device's remaining evidence and review.
Before you start
- Have permission to create calibration events and perform procedure execution. Reading a session also requires access to its calibration and procedure evidence.
- Prepare active equipment requirements pinned to the same exact approved, effective, group-enabled procedure revision.
- Check your technical authorisation for the method, performed date and actual site. Resolve conflicting active work or work-order assignments before starting.
- Confirm that all selected work belongs to one performed calendar date, approved revision and actual execution site. Split work with different context into another session.
If the start page says new groups are disabled, ask an administrator to complete the rollout. Existing saved sessions can still be opened with the relevant permissions. Ordinary individual calibration remains available through Record calibration work.
Prepare the approved procedure
In the procedure revision editor, enable Allow group execution and choose Shared or Per-device for every step. Existing steps remain per-device. Submit the revision through the usual independent review and approval before starting a group. Follow Prepare a procedure for multiple devices for the authoring steps and a two-point example.
Share instructions, apparatus setup, environmental observations and stabilisation when the method allows it. Keep inspections, measured indications, adjustments, calculations and conformity decisions per-device. A shared declaration never replaces individual readiness or independent review.
For each calibration point, define a shared stabilisation step with a stable Calibration point key. Define a later per-device measurement step with the same key and one nominal value. Repeat for each approved point. For example, one point may stabilise a bath at 0 °C, followed by each sensor's readings; the next point may be 50 °C. The method controls the points, values, unit and ordering.
Select and check the group
- From Calibration work or a work order, choose Start group calibration.
- Select equipment and calibration requirements with the same exact approved revision. One row means one equipment/requirement pair; multiple requirements on one asset stay separate.
- Search and move between pages without losing your selection. Select eligible on this page selects the visible page only. The selection limit is shown above the table.
- Choose Continue to review the complete roster, Session title, Performed date, Actual place of work and Work site.
- Choose Check group eligibility to check technical authorisation, compatibility, active work, actual site and evidence requirements for every participant. Resolve the listed device blockers. Changing the title, date, site or roster requires another check.
- Choose Create group. Metra rechecks the proposal while creating the events. A failed start retains the proposal and creates no partial group.
A work order is optional. Starting from a work order scopes the available work to that order; it does not select every item automatically. Starting creates one event per selected requirement. Review each event's recipient and report identity in its individual Result summary. Creating the group does not imply a passed calibration or release for use.
The session pins the performed calendar date, approved procedure revision and actual execution site. Individual event edits cannot move one participant to another date, procedure or site; start another session when that context differs.
Shared setup and point observations
Open Shared steps, read the controlled instruction and record actual apparatus, reference and environmental evidence. The server checks authority and reference fitness across all active devices. Resolve a blocked participant or withdraw it with a reason; do not bypass an authorisation restriction.
For a shared reference step, choose the reference standard, the capability band actually used and its approved source calibration. Record actual evidence for each condition instead of assuming it is satisfied. Metra creates and assesses separate reference usage for every device, including its range, method, site and measurement sets. One shared choice never grants blanket eligibility. A device-specific exception must use its normal individual reference review.
Coverage can remain pending until a device has the corresponding saved measurement sets. Saving that device's readings refreshes its reference assessment. Check its individual readiness again before completing or submitting; selecting the standard once does not by itself finish every device's reference evidence.
At each stabilisation point enter the bath setpoint, Observed reference value, unit, stabilisation duration and actual observation time in UTC. The setpoint and reference observation are different evidence. A bath set to 0 °C may have a measured reference of 0.02 °C. A shared duration-only stabilisation without a point key asks for its duration rather than fictitious bath observations.
Saving records the shared evidence, actor, time and the devices actually present. The roster freezes when execution begins. Late devices need another session. Withdraw a device with a reason from Device overview; its earlier evidence and participation remain visible.
If another operator changes the pre-start roster while you are editing it, your proposed list stays on screen. Compare the latest saved participants, then explicitly reapply your proposal against that version. If execution has started, the roster stays frozen.
Individual readings and readiness
In Device readings, select the approved point and enter each device's indication and observation time. Asset IDs and serials remain in stable roster order. Tab moves between fields; Enter saves the current indication row and moves to the next device. On small screens each device becomes a labelled form.
Each row saves independently after complete input or Save this device. Watch its saved, saving, failed or conflict state. Blank means missing, never zero. The backend calculates error against the frozen observed reference. It does not calculate error against the bath setpoint. Use Individual readings for repeated observations or other detailed evidence.
The current point stays visible while scrolling. Open Device evidence readiness to see that device's remaining prerequisites. A filtered roster stays in place while you enter readings; use Refresh device filter when you want saved rows to leave the filtered view. Edits made during a pending save are retained and saved in a subsequent request.
Lower and upper acceptance limits are absolute acceptable device indications in the point unit, for example 49.5–50.5 °C at a 50 °C point. Enter the approved limits for each device. Limits are not error bands and are never copied between rows. The server remains responsible for calculations and conformity.
If one device fails to save, other saved devices remain saved. Retry that device only. A conflict retains your entry: compare the latest indication, time, limits and exact reference revision, then explicitly reapply after checking them. You may view another point after acknowledging incomplete devices. Recording the next required shared operation requires finishing the earlier required steps or withdrawing the affected device with a reason. Missing evidence stays missing; changing the view does not advance the controlled method.
A recorded failed individual outcome is retained and can satisfy that step's sequencing requirement without becoming a pass. Its device still follows normal result and out-of-tolerance controls. A skipped or not-applicable outcome whose required deviation was revoked does not satisfy the prerequisite; resolve it through the normal controlled procedure.
Use Device overview to filter incomplete, failed or withdrawn devices. Follow the individual procedure, results, reference standards, uncertainty, conformity and review links to resolve prerequisites. Complete each device's procedure separately. Completing procedure work is different from accepting a calibration result or releasing equipment.
Submit and review independently
Submit selected devices starts with no selection. Select ready devices explicitly, check the roster, result, exact linked shared revision and declaration, then submit only the reviewed selection. Each device uses the normal submission checks independently. The normal electronic-signature control checks the organisation's policy, your active signature and recent authentication. An explicitly selected signature is applied separately to each chosen device's submission; it never approves the devices. Use individual review for different signature choices. Reconciliation retains the original choice for each submitted device.
The outcome list shows persisted successes and failures. If the connection is interrupted, use Reconcile previous submission; the same operation identity recovers the saved outcome without submitting successful devices twice. Returning to the session shows the saved device states.
A reviewer checks and approves each device separately. Shared-evidence contributors are subject to the same independence rules as individual evidence contributors. Failed and indeterminate results retain their out-of-tolerance and release restrictions. Certificates remain individual.
See Review procedure execution evidence for checking a device's frozen shared revision, attributed observations and reviewer eligibility. A ready device can be selected without selecting an incomplete one; this does not bypass the earlier required sequence for recording shared work.
Individual device pages provide Previous device, Next device and Return to group links. Review navigation opens the next device's own review; no decision or declaration is reused. Save current work before moving between devices; unsaved-change protection still applies.
Correct shared evidence safely
Select a saved shared step, enter the corrected observation and reason, then choose Review shared correction. Compare the previous response and revision with the proposed replacement and check the listed devices. Drafts require explicit adoption; submitted or approved devices require normal amendment. Back to correction retains your entries. Save corrected revision creates the new evidence only after this review. The original revision and hash remain fixed.
Open Shared correction impacts to compare the previous and corrected evidence and each affected device's disposition. An editable device must explicitly adopt the latest corrected revision and revalidate its evidence. Older pending impact cards direct you to the latest correction. The adopting operator must hold the normal qualification for the actual site; the adopter becomes an evidence contributor for independent-review checks. Submitted and approved events retain the original frozen revision; use normal amendment or supersession for an accepted correction. A correction never silently changes an approved certificate, result or due date.
Resume later
Use Resume a group calibration session from Calibration work. Saved shared evidence, roster, individual readings and submission outcomes are retained online. Unsaved entry warnings help you avoid leaving a failed save behind. Offline working is not supported.
Sign out checks unfinished group selections, shared responses, device readings, roster changes, withdrawal reasons and individual procedure responses in connected Metra tabs. Choose Stay and save or Cancel to keep the open entries without starting sign-out. Pending or failed saves remain unfinished until their saved confirmation. Confirming discard immediately hides the workspace and erases local entries, even if server sign-out fails and needs a retry. These entries have no local draft recovery; saved server evidence remains available through normal permissions.
When returning to a session, use Device overview to find unfinished devices, Shared steps to inspect saved operations and Device readings to continue the correct point. Before repeating a submission after an interrupted connection, use its reconciliation action and inspect the saved per-device outcomes.
If selection, shared work, a device save or submission is blocked, follow Resolve group-calibration problems. Keep failed or conflicting entries visible while checking the saved evidence; a warning is not a saved confirmation.