Enter the airflow (CFM/CMM) and the sensor’s airflow range to convert between airflow and a linear analog signal (voltage or mA). This is not a universal “CFM to voltage” physics conversion; it applies only to sensors/controllers that use linear scaling.
Cfm To Voltage Formula
The following formula is used to convert between airflow (CFM/CMM) and a linear analog sensor/controller output (voltage or current) when the device is configured for a known airflow range.
V = V_{min} + \frac{(Q - Q_{min})}{(Q_{max}-Q_{min})}\,(V_{max}-V_{min})Variables:
- V is the sensor/controller output signal (typically volts, V, or milliamps, mA)
- Q is the airflow (typically CFM or CMM)
- Qmin is the configured minimum airflow for the sensor’s range
- Qmax is the configured maximum airflow for the sensor’s range
- Vmin and Vmax are the minimum and maximum signal levels (for example, 0–10 V, 2–10 V, 1–5 V, 0–5 V, or 4–20 mA)
To calculate the signal from airflow, subtract the minimum airflow, divide by the airflow span, then scale by the signal span and add the minimum signal. (The “Main” tab assumes a 0–10 V linear output.)
| Airflow (CFM) | Voltage (V) | Voltage (kV) |
|---|---|---|
| 5 | 0.0250 | 0.000025 |
| 10 | 0.0500 | 0.000050 |
| 15 | 0.0750 | 0.000075 |
| 20 | 0.1000 | 0.000100 |
| 25 | 0.1250 | 0.000125 |
| 30 | 0.1500 | 0.000150 |
| 40 | 0.2000 | 0.000200 |
| 50 | 0.2500 | 0.000250 |
| 75 | 0.3750 | 0.000375 |
| 100 | 0.5000 | 0.000500 |
| 150 | 0.7500 | 0.000750 |
| 200 | 1.0000 | 0.001000 |
| 250 | 1.2500 | 0.001250 |
| 300 | 1.5000 | 0.001500 |
| 400 | 2.0000 | 0.002000 |
| 500 | 2.5000 | 0.002500 |
| 750 | 3.7500 | 0.003750 |
| 1000 | 5.0000 | 0.005000 |
| 1500 | 7.5000 | 0.007500 |
| 2000 | 10.0000 | 0.010000 |
| *This table shows linear sensor scaling, not a universal physical conversion. Assumes airflow range Qmin=0 CFM to Qmax=2000 CFM mapped to a 0–10 V output (Vmin=0, Vmax=10). | ||
What is Cfm To Voltage?
“CFM to voltage” most commonly refers to converting an airflow value into the analog output signal from an airflow sensor/transmitter (or the reverse). The conversion depends on the device’s configured range (minimum and maximum airflow) and its signal type (such as 0–10 V, 2–10 V, 0–5 V, 1–5 V, or 4–20 mA). Without that sensor scaling information, airflow (CFM) and voltage are not directly interchangeable.
How to Calculate Cfm To Voltage?
The following steps outline how to calculate CFM to voltage for a linear sensor output.
- Determine the airflow (Q) in CFM (or CMM).
- Determine the sensor’s airflow range minimum (Qmin).
- Determine the sensor’s airflow range maximum (Qmax).
- Determine the sensor’s signal range (for example, 0–10 V or 4–20 mA) and then calculate the signal using the linear scaling formula.
- After inserting the values and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Airflow (Q) = 500 CFM
Range Min (Qmin) = 0 CFM
Range Max (Qmax) = 2000 CFM (for a 0–10 V sensor: V = (500 − 0) / (2000 − 0) × 10 = 2.5 V)