Glossary
This glossary defines the terms used throughout Obsidian Metra. For explanations with examples, start with the Calibration concepts guides linked below. The procedural guides explain how to record and manage the information.
Organisations and access
Organisation
The primary workspace and data boundary in Obsidian Metra. Equipment, clients, sites, members, calibration records, evidence, and audit history belong to one organisation and are not shared automatically with another organisation.
An organisation is your own operating entity in the system. It is not the same as a client. See Get started with Metra.
Member
A person who has been invited to or joined an organisation. The same person can be a member of more than one organisation.
Membership
The relationship between a person and one organisation. It records that person's organisation-specific role and access status. Suspending or revoking one membership does not remove the person's memberships in other organisations.
Role
A named collection of responsibilities appropriate to a type of member, such as owner, organisation administrator, quality manager, calibration manager, or calibration engineer. A person's role is scoped to one organisation.
Permission
Authority to perform a specific action, such as approving calibration work, replacing a certificate, reviewing a dossier, or downloading an export. Permissions are granted through the member's role and checked by the system for each protected action.
A role describes a member's general responsibilities; a permission controls a particular action. See Roles and permissions.
Clients, sites, and locations
Client
An external customer or other client entity whose sites may contain deployed equipment. A client belongs to the selected organisation but is not an application workspace or user account.
Site
A physical facility or operational place. A site has an IANA timezone used for due dates and notifications, and it may belong to a client. Equipment can be assigned directly to a site or to a location within it.
A site is the main assignment and timezone boundary. It is not an organisation, and it is more specific than a client.
Location
A named area within a site, such as a building, laboratory, production line, room, or cabinet. Locations can form a hierarchy beneath their site.
A location cannot belong to a different site from its parent. See Create sites and location hierarchies.
Equipment and movement
Equipment
The physical instrument, sensor, reference standard, or other asset being controlled. An equipment record holds the asset identity and lifecycle; calibration schedules and completed calibration work are separate records linked to it.
Equipment is not a calibration requirement or a calibration event. See Register equipment.
Equipment category
A reusable classification for equipment, such as temperature sensor or pressure gauge. A category helps organise similar assets but does not define an individual item's calibration schedule.
Deployment
A dated interval describing where equipment was assigned, including its client, site, location, and responsible member where applicable. Deployment history is used to reconstruct where an item was present during an audit period.
Deployments use exact effective timestamps and do not replace the equipment lifecycle status. See Deployment reference.
Rotation pool
The state in which equipment has no current client, site, or location assignment and is available for a future deployment. Returning equipment to rotation closes its current deployment interval without deleting its history.
Being in rotation does not by itself change the equipment's lifecycle status or calibration requirements. See Equipment and rotation.
Measurement and calibration concepts
Calibration
Establishing the relationship between an instrument's indications and reference values, with their associated measurement uncertainties, under stated conditions. Calibration provides information about measurement performance; adjustment changes the instrument, while verification checks whether specified requirements are met. See Calibration and traceability.
Measurand
The quantity intended to be measured, including the conditions needed to define it. For example, the temperature of a particular bath at a stated position is more specific than just “temperature”.
Measurement error and correction
Measurement error is a measured value minus a reference value. A correction compensates for an estimated systematic effect; for a simple additive correction it has the opposite sign to that estimated error. Neither tells you the measurement uncertainty on its own. See Read a calibration certificate.
Measurement uncertainty
A non-negative value describing the spread of values that could reasonably be attributed to the measurand, based on the information available. It describes how well the result is known, rather than the permitted error or a mistake by the operator. See Measurement uncertainty.
Standard and expanded uncertainty
Standard uncertainty expresses uncertainty as a standard deviation. Combined standard uncertainty brings the component contributions together using the measurement model. Expanded uncertainty is the combined standard uncertainty multiplied by a coverage factor.
Coverage factor
The multiplier, usually written k, used to obtain expanded uncertainty from combined standard uncertainty. The coverage probability depends on the distribution and other assumptions; k = 2 is not automatically an exact 95% guarantee. See Coverage factors and degrees of freedom.
Tolerance
The permitted limits for a specified property, value or error. Tolerance describes what is acceptable for the intended use; uncertainty describes how well a measurement result is known. See Tolerances and decision rules.
Decision rule
The agreed method for deciding whether a measurement meets a requirement, including how measurement uncertainty is taken into account. A conformity statement such as pass or fail needs both the applicable limits and a decision rule.
Guard band
A margin between a tolerance limit and the corresponding acceptance limit. It can narrow the range accepted as passing to manage the risk of an incorrect conformity decision. The chosen decision rule defines how it is applied.
Metrological traceability
The property of a measurement result that allows it to be related to a stated reference through a documented, unbroken chain of calibrations, each contributing to uncertainty. It concerns the measurement result, not simply whether an instrument has a certificate. See Calibration and traceability.
Accreditation concepts
Accreditation
Formal recognition by an accreditation body that an organisation is competent to perform specified activities. It applies to the activities and conditions in the accredited scope. See Accreditation and scopes.
Accreditation profile
Metra's controlled record of an accreditation identity, claims, scope entries, validity and approved mark. Recording or approving a profile in Metra does not grant accreditation. See Manage accreditation profiles.
Accreditation scope
The defined activities covered by accreditation, including relevant measurements, instruments, ranges, methods, locations and conditions. One Metra accreditation profile can hold several scope entries. An accreditation scope is different from the client, site and date selection of a dossier scope. See Accreditation and scopes.
Calibration and measurement capability (CMC)
A calibration or measurement capability available to customers under normal conditions, as described in the recognised scope. Its stated uncertainty relates to the specified capability and conditions; it is not automatically the uncertainty achieved for every customer's instrument. See Measurement uncertainty.
Calibration planning and work
Calibration requirement
A recurring obligation attached to one equipment item. It defines what work is required, its interval, warning period, approval expectations, responsibility, and current schedule.
One equipment item can have several requirements, such as annual external calibration and six-monthly verification. See Create a calibration requirement.
Requirement template
A reusable starting point for creating similar calibration requirements on multiple equipment items. Assigning a template copies controlled values into independent equipment requirements.
Changing a template does not silently rewrite requirements already created from it. See Create and revise requirement templates.
Calibration event
A record of specific calibration or verification work performed against one calibration requirement. It includes the performed date, result, performer, submitted evidence, review history, and frozen requirement details.
An event is completed work; a requirement is the recurring obligation that caused the work. See Record calibration work.
Calibration certificate
A retained file that provides documentary evidence for a calibration event. Replacing a certificate creates a new version and preserves the superseded version, metadata, checksum, and replacement history.
A certificate is evidence for an event; it is not the event itself. See Upload or replace a calibration certificate.
Due date
The calendar date by which a calibration requirement is next expected. It can originate from the initial schedule, an approved acceptable calibration event, or a controlled manual adjustment.
Due status
Metra-calculated relationship between a requirement's next due date and the equipment site's current local date. Examples include current, due soon, due today, overdue, suspended, and not applicable.
Due status is a calculated operational view, not a separately entered result. See Calibration status reference and Dates, timezones, and timestamps.
Independent review
A workflow control requiring an authorised person other than the preparer, performer, or submitter to review controlled work. The exact separation rule depends on the record being reviewed.
Uncertainty budget
A structured list of the sources of uncertainty and how they combine. In Metra it is a controlled, revisioned definition of the components and calculation assumptions. See Measurement uncertainty before authoring a budget.
Uncertainty evaluation
Saved evidence for one measurement point, containing the exact budget revision, observations, resolved source values, component contributions, combined standard uncertainty, effective degrees of freedom, coverage factor, expanded uncertainty, findings, and integrity hash.
Nonconforming work
Out-of-tolerance case
A controlled investigation opened from an approved failed or indeterminate calibration result. It records containment, impact assessment, investigation, disposition, corrective actions, and independent quality review.
The case investigates the unacceptable or uncertain result; it does not replace the source calibration event. See Complete an out-of-tolerance investigation.
Corrective action
A specific action used to address a cause, impact, or control weakness identified during an out-of-tolerance investigation. It has its own description, responsibility, due date where applicable, status, and completion evidence.
A corrective action is one part of an investigation, not the investigation itself. See Out-of-tolerance status reference.
Audit history and exports
Audit event
An append-only record of a significant action, including who acted, when it happened, the organisation, the action type, and safe before-and-after context where applicable.
An audit event records activity metadata; it is not a calibration event. See Search the audit trail.
Compliance export
A temporary CSV or ZIP generated asynchronously from frozen filters and a point-in-time snapshot. Export files expire after their download window, while source records, job metadata, checksums, and audit history remain.
An export is a derived download, not the official record. See Create a compliance export.
Equipment evidence pack
A compliance export in ZIP format for selected equipment. It combines equipment and calibration summaries with retained evidence files and a checksum manifest.
An evidence pack is narrower and operationally focused compared with an ISO audit dossier. See Generate an equipment evidence pack.
Checksum
A cryptographic fingerprint, recorded as SHA-256, used to verify that a file has not changed. Matching checksums provide an integrity check; they do not by themselves prove that the content is correct or approved.
See Evidence and download retention.
ISO audit preparation
ISO audit profile
The reusable organisation-level record of declared audit scope, management-system route, default period, and related profile details used when preparing ISO 17025 evidence.
The profile is not a dossier and does not select a dossier's clients or sites. See Set up the ISO 17025 audit profile.
Evidence requirement
A structured audit topic against which evidence can be assessed and linked. Its applicability can be recorded as applicable, not applicable with a rationale, or not assessed.
An evidence requirement describes what supporting evidence is expected; it is not the evidence file itself.
Controlled evidence document
An organisation-supplied document with a stable identity, descriptive metadata, lifecycle status, and one or more fixed PDF revisions. Examples can include policies, procedures, competence records, and management-system evidence.
Controlled evidence revision
One fixed uploaded version of a controlled evidence document. A later approved revision supersedes the earlier approved revision without deleting it.
The document is the continuing identity; a revision is the exact file version. See Manage the controlled evidence library.
Readiness
A neutral view of evidence health and gaps across the audit profile, applicability decisions, linked evidence, review dates, expiry dates, and personnel records.
Readiness is not a conformity score, pass/fail decision, or accreditation assessment. See Review ISO 17025 audit readiness.
Personnel technical authorisation
A controlled record of a member's authorised technical activity or method, scope, limits, effective dates, approver, and supporting evidence.
Technical authorisation records competence-related scope; an application role controls system access. One does not substitute for the other. See Record personnel technical authorisations.
Dossier
A point-in-time audit evidence package prepared for an explicit client-site scope and inclusive period. Submission freezes the selected source records for independent review before asynchronous ZIP generation.
A dossier supports audit preparation but does not determine conformity or provide accreditation. See ISO 17025 dossiers.
Dossier revision
One fixed iteration of a dossier title and audit profile. A new revision is required when frozen scope or evidence must change, or when an expired or failed generated package must be replaced.
A dossier revision is not the same as a controlled evidence revision: one freezes a complete evidence selection, while the other identifies one uploaded document version.
Evidence mode
The dossier setting that controls which calibration-event states are eligible for the frozen selection. The user interface offers final evidence only or inclusion of all work, depending on the audit purpose.
Choosing a broader mode exposes non-final states for traceability; it does not approve them. See ISO 17025 dossier reference.
Dossier scope
The explicit combination of selected client-backed sites and an inclusive date period. Historical equipment is resolved from deployment intervals that overlap that scope, not only from current assignments.
See Select dossier scope.
Revision
A retained version or controlled iteration of a record. The exact meaning depends on the record: a certificate version preserves a replaced file, a controlled evidence revision preserves an uploaded document file, and a dossier revision preserves a frozen evidence selection.
Creating a revision preserves history; it is not the same as overwriting the previous record.
Reference-standard terms
Reference standard: An equipment-backed controlled asset used to support calibration measurements.
Capability band: A quantity, unit, inclusive range, expanded uncertainty, coverage factor, and conditions under which a standard may be used.
Traceability assessment: A policy-versioned, reason-coded evaluation of whether every applicable evidence branch reaches an accepted terminal.
Controlled exception: An authorised reason for proceeding with prohibited standard use; it does not change the calculated prohibition.