FieldengInstrumentation & Controls
Maximum Loop Resistance
Maximum series resistance a 4–20 mA loop can tolerate at full-scale current.
Instrumentation & ControlsElectrical & Power
Maximum series resistance a 4–20 mA loop can tolerate at full-scale current.
App id: INST-10. 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
Rmax = (Vsupply − Vtx,min) / ImaxInputs
| Name | Unit |
|---|---|
| Supply voltage | V |
| Transmitter minimum voltage | V |
| Maximum loop current (optional) | mA |
Outputs
| Name | Unit |
|---|---|
| Maximum loop resistance (hero result) | ohm |
Diagnose
This tool does not attach diagnose observations.
Assumptions
- Leave maximum current blank for 20 mA.
Provenance
- Loop power budget at the stated maximum current (default 20 mA).