Some pressure measurements are used to indirectly derive another type of measurand. One of these is the Rate of Flow of a gas or liquid. The flow rate along a closed pipe is directly proportional to the square root of the pressure drop or differential pressure between two points.
Since the relationship is non-linear, there is a greater change in flow at low pressures compared to higher ones. In order to optimise the resolution of flow measurement, the output on some differential pressure transmitters can be altered so that it is directly proportional to the flow rate rather than the differential pressure.
Featured sqrt extraction 4-20ma current loop signal related products
250″wc Orifice plate flow measurement dp transmitter - This differential pressure (dp) transmitter can be used to measure the difference in upstream and downstream flowing pressure either side of a orifice plate.
DPT200 Pressurised Tank Level Differential Pressure Transmitter - Pressurised tank liquid level differential pressure cell transmitter for process plant storage.
Linear → Sq Rt 4-20mA Conversion
The following formula can be used for converting a linear 4-20mA current loop signal to a square root extraction type:
OutputSqRt = 4mA + (4 x √ (OutputLinear – 4mA))
The following table shows values for linear to square root extraction 4 to 20 milliamp current loop signal.
| Linear (mA) | Square Root (mA) |
|---|---|
| 4 | 4.00 |
| 5 | 8.00 |
| 6 | 9.66 |
| 7 | 10.93 |
| 8 | 12.00 |
| 9 | 12.94 |
| 10 | 13.80 |
| 11 | 14.58 |
| 12 | 15.31 |
| 13 | 16.00 |
| 14 | 16.65 |
| 15 | 17.27 |
| 16 | 17.86 |
| 17 | 18.42 |
| 18 | 18.97 |
| 19 | 19.49 |
| 20 | 20.00 |
Convert any linear measurement to sqrt extraction 4-20mA signal
Featured sq rt 4 to 20 milliamp output related products
Universal Strain Gauge Bridge Input Transmitter – STRAIN - Simplify your strain measurement setup with the STRAIN Universal Strain Gauge Bridge Input Transmitter. This versatile device converts mV signals from strain gauges, load cells, and pressure transducers into 0-10Vdc, 0-20mA, or 4-20mA outputs.
Pitot tube air flow calculation 1000 hPa differential pressure transmitter - Air flow differential pressure transmitter for measuring difference between pitot tube and static port pressure up to 1000 hectopascals.
Sq Rt → Linear 4-20mA Conversion
The formula for converting a square root extraction 4-20mA signal to a linear one is:
OutputLinear = 4mA + ((OutputSqRt – 4mA)² / 16)
The following table shows values for square root extraction to linear 4 to 20 milliamp current loop signal.
| Square Root (mA) | Linear (mA) |
|---|---|
| 4 | 4.00 |
| 5 | 4.06 |
| 6 | 4.25 |
| 7 | 4.56 |
| 8 | 5.00 |
| 9 | 5.56 |
| 10 | 6.25 |
| 11 | 7.06 |
| 12 | 8.00 |
| 13 | 9.06 |
| 14 | 10.25 |
| 15 | 11.56 |
| 16 | 13.00 |
| 17 | 14.56 |
| 18 | 16.25 |
| 19 | 18.06 |
| 20 | 20.00 |
Convert sqrt extraction 4-20mA signal to any linear measurement
Featured square root extraction 4-20ma signal related products
- 10 kPa orifice plate differential pressure transmitter for water flow measurement - Pressure sensor for measuring the differential pressure generated by water flowing through an orifice plate in a pipe, and converting the output to a water flow measurement.
- Pitot tube air flow calculation 1000 hPa differential pressure transmitter - Air flow differential pressure transmitter for measuring difference between pitot tube and static port pressure up to 1000 hectopascals.