4–20 mA to -1–1.5 bar: scaling table
A transmitter calibrated -1–1.5 bar: 4 mA = -1 bar, 20 mA = 1.5 bar. Linear output.
At a glance
- Span
- 2.5 bar
- Change per 1 mA
- 0.15625 bar
- Change per 1 %
- 0.025 bar
- Value at 12 mA
- 0.25 bar
Scaling table
| Current (mA) | Output (%) | Value (bar) |
|---|---|---|
| 4.00 | 0 % | -1 |
| 6.00 | 12.5 % | -0.6875 |
| 8.00 | 25 % | -0.375 |
| 10.00 | 37.5 % | -0.0625 |
| 12.00 | 50 % | 0.25 |
| 14.00 | 62.5 % | 0.5625 |
| 16.00 | 75 % | 0.875 |
| 18.00 | 87.5 % | 1.1875 |
| 20.00 | 100 % | 1.5 |
NAMUR NE 43 limits in bar
| Current (mA) | Value (bar) | Meaning |
|---|---|---|
| 3.6 | -1.0625 | Failure signal, downscale (≤ 3.6 mA) |
| 3.8 | -1.03125 | Lower measuring limit (3.8 mA) |
| 20.5 | 1.57813 | Upper measuring limit (20.5 mA) |
| 21.0 | 1.65625 | Failure signal, upscale (≥ 21 mA) |
Formula
PV = -1 + (I − 4) / 16 × 2.5 bar
Example: a reading of 13.6 mA corresponds to 0.5 bar. Going the other way, 0.875 bar corresponds to 16 mA.
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