Instrumentation Calculators

# 4 – 20 mA to 1 – 5V, 3 -15 Psi and 0.2 – 1.0 Bar Signal Conversion Calculator

• Converting electrical signals, like current, into physical measurements, like voltage or pneumatic signals, is essential for many kinds of processes in industrial and engineering environments.
• Following standard instrumentation practices, this  instrumentation tool makes the process of converting easier by focusing on turning a 4–20 mA current signal into voltage or pneumatic signal readings within certain ranges.
• Engineers and technicians can rely on this calculator for efficient troubleshooting, project activities, commissioning  and maintenance, ensuring reliable industrial and engineering processes while adhering to established instrument standards.

Let us assume that you need to convert a standard current signal (I) in the 4–20 mA range to a standard voltage signal (V) in the 1–5 volt range.

Here’s the formula:

The output voltage signal  is

V = Vmin+{(I-Imin)/(Imax-Imin)} X (Vmax-Vmin)

Where:

• V is the output voltage in volts (between 1 and 5 volts)
• I is the input current in mA (between 4 and 20 mA)
• Vmin is the minimum output voltage (1 volt)
• Vmax is the maximum output voltage (5 volts)
• Imin is the minimum input current (4 mA)
• Imax is the maximum input current (20 mA)

Let’s say we have an input current signal I of 12 mA, and we want to calculate the corresponding output voltage V.

Given:

• I=12 mA (input current)
• Vmin=1 V (minimum output voltage)
• Vmax=5 V (maximum output voltage)
• Imin=4 mA (minimum input current)
• Imax=20 mA (maximum input current)

Now, we’ll input these values into the formula:

V=1+(12−4)/(20−4)×(5−1)

V=1 + ((8/16) X 4)

V=1+2

V=3​

So, for an input current signal of 12 mA, the corresponding output voltage signal is 3 V.

This calculation demonstrates how to convert an input current within the 4-20 mA range to the corresponding output voltage within the 1-5 V range using a linear relationship. You can repeat this process for any other input current value within the specified range to find its corresponding output voltage.

Similar to the previous example, we’ll be converting a current signal (I) in the 4–20 mA range to a standard pneumatic signal (P) in the 3–15 psi range.

Here’s the formula:

The output pressure is

P = Pmin + {(I – Imin) / (Imax – Imin)} × (Pmax – Pmin)

Where:

P is the output pressure (Pneumatic signal) in psi (between 3 and 15 psi)

I is the input current in mA (between 4 and 20 mA)

Pmin is the minimum output pressure (3 psi)

Pmax is the maximum output pressure (15 psi)

Imin is the minimum input current (4 mA)

Imax is the maximum input current signal  (20 mA)

Let’s say we have an input current signal I of 12 mA, and we want to calculate the corresponding output pressure P.

Given:

I = 12 mA (input current)

Pmin = 3 psi (minimum output pressure)

Pmax = 15 psi (maximum output pressure)

Imin = 4 mA (minimum input current)

Imax = 20 mA (maximum input current)

Now, we’ll input these values into the formula:

P = 3 + ((12 – 4) / (20 – 4)) × (15 – 3)

P = 3 + ((8 / 16) × 12)

P = 3 + 6

P = 9 psi

So, for an input current of 12 mA, the corresponding output pneumatic signal is 9 psi.

This calculation demonstrates how to convert an input current within the 4-20 mA range to the corresponding output pressure within the 3-15 psi range using a linear relationship. You can repeat this process for any other input current value within the specified range to find its corresponding output pressure.

Similar to the previous examples, we’ll be converting a current signal (I) in the 4–20 mA range to a pressure signal (P) in the 0.2–1.0 bar range.

Here’s the formula:

The output pressure is

P = Pmin + {(I – Imin) / (Imax – Imin)} × (Pmax – Pmin)

Where:

P is the output pressure in bar (between 0.2 and 1.0 bar)

I is the input current in mA (between 4 and 20 mA)

Pmin is the minimum output pressure (0.2 bar)

Pmax is the maximum output pressure (1.0 bar)

Imin is the minimum input current (4 mA)

Imax is the maximum input current (20 mA)

Let’s say we have an input current signal I of 12 mA, and we want to calculate the corresponding output pressure P.

Given:

I = 12 mA (input current)

Pmin = 0.2 bar (minimum output pressure)

Pmax = 1.0 bar (maximum output pressure)

Imin = 4 mA (minimum input current)

Imax = 20 mA (maximum input current)

Now, we’ll input these values into the formula:

P = 0.2 + ((12 – 4) / (20 – 4)) × (1.0 – 0.2)

P = 0.2 + ((8 / 16) × 0.8)

P = 0.2 + 0.4

P = 0.6 bar

So, for an input current of 12 mA, the corresponding output pneumatic signal is 0.6 bar.

This calculation demonstrates how to convert an input current within the 4-20 mA range to the corresponding output pressure within the 0.2-1.0 bar range using a linear relationship. You can repeat this process for any other input current value within the specified range to find its corresponding output pressure.

This below calculator is used for converting instrumentation standard signals from 4 to 20 mA to 1 to 5 V, from 3 to 15 Psi, and 0.2 to 1.0 bar.

The below table showing the conversion of a 4-20 mA current signal to voltage (1-5V), pressure (3-15 psi), and pressure (0.2-1.0 bar).