Airflow Sensor Calibration Calculator

Align sensor output with trusted field airflow references. Apply density correction, fit gain and offset. Produce clear calibration records for audits and handover.

Inputs

Enter paired readings: sensor output and trusted reference airflow. Use two points minimum; more points improve robustness.

Units

Keep the same units for all reference values.

Calibration method

Multi-point fit reduces random measurement noise.

Apply density correction

Useful for velocity-pressure based sensing.

Air temperature (°C)

Barometric pressure (kPa)

Relative humidity (%)

Standard density (kg/m³)

Typical commissioning value is 1.204 kg/m³.

Calibration points

Enter sensor output (x) and reference airflow (y). Leave unused rows blank.

Point 1

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Point 2

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Point 3

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Point 4

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Point 5

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Point 6

Sensor reading (x) Reference airflow (y)

Reference must be > 0.

Example data table

These sample points demonstrate a typical commissioning set for a duct airflow sensor.

#	Sensor reading (x)	Reference airflow (y) (CFM)	Notes
1	2.10	980	Low flow setpoint check
2	3.85	1520	Mid-range stability
3	5.10	2010	Typical operating flow
4	6.65	2620	Upper range verification

Formula used

Density factor = √(ρ_std / ρ) (optional).
x' = x × Density factor (when enabled).
Gain (m) = (nΣ(x'y) − Σx'Σy) / (nΣ(x'²) − (Σx')²)
Offset (b) = (Σy − mΣx') / n
Corrected airflow = m × x' + b
Error (%) = (Reading − Reference) / Reference × 100

Two-point fit uses Point 1 and the last valid point. Multi-point regression is recommended for commissioning documentation.

How to use this calculator

Collect paired readings: sensor output and a trusted reference airflow.
Enter at least two points; add more across the operating range.
Optionally enter temperature, pressure, and humidity for density correction.
Click Calculate Calibration to compute gain and offset.
Apply Corrected = Gain × Sensor + Offset in your control system.
Download CSV or PDF to attach to commissioning and handover records.

Tip: Re-run calibration after major ductwork changes or sensor replacement.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.