Quick answer
A bump test checks whether a detector responds to test gas and operates its alarms; it does not establish measurement accuracy. A calibration check compares the reading with a known reference, while calibration adjustment changes the instrument's response to that reference. For a fixed system, the approved test scope must also identify which controller and alarm functions are being verified.
Three terms that should not share one pass box
Industrial Scientific's testing definitions distinguish a functional bump test, which does not measure accuracy or adjust the instrument, from calibration adjustment. MSA's PrimaX IR+ documentation separately describes a span check against a known concentration and acceptable limits. Here, 'calibration check' means that reference comparison, not an adjustment. Manufacturer terminology can differ: read the named method and result, not just the service label. These references explain terminology only; their schedules and procedures are not instructions for a UTAI fixed installation.
When requesting service, ask the provider to name the activity. A line reading 'gas tested: pass' leaves an important question unanswered: was an alarm observed, was accuracy checked against documented limits, or were calibration values changed? Request separate results wherever more than one activity was performed.
Match the result to the question being asked
Use the following comparison as an editorial aid when reviewing a proposed work scope. It is not a test procedure or a replacement for the installed instrument's instructions. The provider should identify the acceptance criteria before reporting a pass.
| Activity | Question for the service record | Do not infer |
|---|---|---|
| Bump or function test | Was the required response observed? | A quantified accuracy result |
| Calibration check | Did the reading meet the stated reference comparison? | That an adjustment was made |
| Calibration adjustment | What comparison was recorded after adjustment? | Acceptance of every connected system function |
Define where the fixed-system test ends
Ask whether the scope ends at the detector or includes its identified controller channel, annunciation and any required downstream interface. Put exclusions in writing. A detector service record and a complete project acceptance record should not have interchangeable titles.
Consider an illustrative report that says 'local alarm observed; accuracy comparison not included; controller test deferred'. Its usable result is the recorded local response, not a complete calibration or system pass. The two excluded activities remain open under their own owners. This is a document-reading example, not a real test result or UTAI field case.
Agree the evidence before the visit
A useful request asks for the instrument identifier, applicable method, reference-gas identity, observed result and acceptance criterion. If adjustment is needed, request results from before and after the work. Ask the provider to distinguish an unsuccessful test from a test that was not completed.
Keep missing records visible. If a report does not identify its method, do not retrospectively call it calibration. The zero-reading explanation addresses display-health limits; this page addresses what a test report permits you to conclude. The UTAI calibration guide supplies broader service-planning context.
An unsatisfactory result needs a disposition
Ask the responsible site person and service provider to state the next action, owner and verification required before the affected equipment is relied upon. Do not rewrite a failed response as an acceptable accuracy check, or treat an unfinished test as a pass because the display looks normal.
This comparison provides no gas-application or control-operation instructions. If an alarm occurs outside the approved test arrangements, follow the site emergency plan first. Testing and any effect on monitoring or connected equipment require an approved work scope managed by competent personnel.