FieldengInstrumentation & Controls
Loop Current Diagnostic
Where a measured loop current sits relative to live zero/full scale, with NAMUR-style band context — not a device verdict.
Instrumentation & ControlsElectrical & Power
Where a measured loop current sits relative to live zero/full scale, with NAMUR-style band context — not a device verdict.
App id: INST-39. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
f = (I − 4 mA) / 16 mAInputs
| Name | Unit |
|---|---|
| Loop current (camera) | mA |
| Live zero (optional) | mA |
| Live full scale (optional) | mA |
Outputs
| Name | Unit |
|---|---|
| Span (hero result) | % |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
loop current < 3.6 mA | Below 3.6 mA | warning |
loop current < live zero | Below live zero | caution |
loop current > 21 mA | Above 21 mA | warning |
loop current > live full | Above live full scale | caution |
loop current ≤ live full | In measurement range | info |
Assumptions
- Same scaling as INST-01. Use INST-01 when you only need percent span.
Provenance
- NAMUR NE43 3.6 mA / 21 mA bands are common, not universal. Confirm the transmitter’s fault convention.