FieldengInstrumentation & Controls
4–20 mA Loop Burden
Voltage drop across series loop devices and remaining supply voltage.
Instrumentation & ControlsElectrical & Power
Voltage drop across series loop devices and remaining supply voltage.
App id: INST-09. 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
V = I ΣRInputs
| Name | Unit |
|---|---|
| Loop current (camera) | mA |
| Resistance 1 | ohm |
| Resistance 2 (optional) | ohm |
| Resistance 3 (optional) | ohm |
| Supply voltage (optional) | V |
| Transmitter minimum (optional) | V |
Outputs
| Name | Unit |
|---|---|
| Total drop (hero result) | V |
| Remaining voltage | V |
| Drop 1 | V |
| Drop 2 | V |
| Drop 3 | V |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Remaining voltage < Transmitter minimum | Insufficient transmitter headroom | warning |
Remaining voltage < Transmitter minimum + 2 | Thin voltage margin | caution |
Assumptions
- Without a supply voltage, remaining equals zero net (drop − drop). Enter supply to see headroom.
Provenance
- Series loop Ohm’s law. Leave extra resistances blank when unused.