INSTRUMENTATION
Read a linear transmitter signal as pressure, temperature, level or another engineering value.
Enter your values, then select Calculate.
Value = LRV + ((mA − 4) / 16) × (URV − LRV).
Linear scaling only. Does not apply directly to square-root extracted flow signals. Out-of-range signals are extrapolated and flagged; consult the device manual for fault thresholds.
Calculation reviewed: 4 October 2026 · Engineering Desk Tools
Read a linear transmitter signal as pressure, temperature, level or another engineering value. Start with measurements or documented values for the equipment and reporting period you actually want to assess. The calculator does not fill in a typical installation for you. Its blank fields help keep a demonstration value from being mistaken for your own operating data.
Choose the required options, enter the values in the labelled units and select Calculate. If a field is rejected, check its range and unit before changing it. The result is accompanied by the equation and assumptions so you can decide whether it answers your engineering question.
Record the measurement source and operating condition. Retain unrounded values for verification.
A 4 mA signal corresponds to the lower range value, 20 mA to the upper range, and 12 mA to the midpoint of a linear range. The engineering unit comes from the transmitter configuration. A pressure range, temperature range and level range can use the same arithmetic while producing completely different physical quantities.
Value = LRV + ((mA − 4) / 16) × (URV − LRV).
Linear scaling only. Does not apply directly to square-root extracted flow signals. Out-of-range signals are extrapolated and flagged; consult the device manual for fault thresholds.
This example does not populate the form. Enter your own installation data.
| Input | Example value |
|---|---|
| Measured signal (mA) | 12 |
| Lower range value (at 4 mA) | 0 |
| Upper range value (at 20 mA) | 100 |
Calculated result: 50 engineering units. 50% of span
Check the arithmetic independently using the displayed equation. Retain intermediate precision and compare the final value with your equipment documentation.
| Changed input | Calculated result |
|---|---|
| Measured signal (mA): 6 | 12.5 engineering units |
| Measured signal (mA): 12 | 50 engineering units |
| Measured signal (mA): 18 | 87.5 engineering units |
These illustrative rows retain the worked example assumptions except for the varied input. They are not certified ratings or manufacturer data. Use the form for intermediate values.
Using a zero-based 0–20 mA formula on a 4–20 mA transmitter; entering an outdated range; applying linear scaling to an unprocessed square-root flow signal. Before relying on the output, check the decimal format, unit scale and source of each value. Recheck unusual results against the formula.
No. Inputs remain blank when the tool opens or when you clear them. The worked example and table are reading material below the calculator. Enter the actual values you want to check each time, and label saved reports so their context is not lost.
The result is the process value the transmitter is reporting for the measured current, based on its configured range. A reading outside 4 to 20 mA is extrapolated, so check the device fault thresholds.
The allowed range follows the meaning of each input. A divisor needs a positive value; other fields may allow zero. Engineering range endpoints may be negative. A rejected input must be corrected before a result can be shown.
No. Linear scaling only. Does not apply directly to square-root extracted flow signals. Out-of-range signals are extrapolated and flagged; consult the device manual for fault thresholds. Use the calculation as support for a checked decision, and review equipment documentation and applicable requirements before changing an installation or operating setting.
Calculate first, then use Copy result or Print report. Some maintenance tools also provide a CSV summary. Reports contain your own entered data, so review them before sharing. You can share the public page URL without including plant records or confidential measurements.
Use the Contact page and include the tool URL, input values, units, expected output and the reference you used. Explain the measurement basis. Exclude confidential information.
Use related calculations with consistent units, periods and equipment scope.