Ppm

Overview

Engineering reference data for Ppm in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Unit Conversions

The relationship between ppm and common percentage or fractional units is as follows:

$$1 \text{ ppm} = 10^{-6} = 0.0001\% = 0.001\text{‰}$$ $$1000 \text{ ppm} = 0.1\%$$ $$10,000 \text{ ppm} = 1\%$$

Mass per Unit Volume Equivalents

One part per million (ppm) is equivalent to a concentration of 1 milligram per liter (mg/L) in water. Other common conversions include:

• 1 ppm = 1 milligram per liter (mg/L)
• 1 ppm = 1 microlitre (μL) per liter
• 1 ppm = 0.001 gram per litre
• 1 ppm = 8.345 pounds per million gallons of water

Related Concentration Units

Parts per million (ppm) is part of a family of dimensionless concentration measures for very small levels.

Volume Concentration Example

The volume of a component in a mixture can be calculated from its ppm concentration. For example, the concentration of carbon dioxide in air is approximately 400 ppm. The volume of CO2 in 1 m³ of air is:

$$c = \frac{(\text{ppm} \cdot s)}{10^6} = \frac{(400 \text{ ppm}) (1 \text{ m}^3)}{10^6} = 0.0004 \text{ m}^3/\text{m}^3$$

Solution Concentration Terms

• Percent by Volume: Expresses concentration as volume of solute per total volume. Calculated as:

  $$\text{percent by volume} = \frac{100 \cdot v_c}{v_c + v_s}$$

  where $v_c$ is the volume of the component and $v_s$ is the volume of the solvent.

• Molarity (M): The number of moles of solute dissolved in one liter of solution (moles/L).

• Molality (m): The number of moles of solute divided by the mass of the solvent in kilograms (moles/kg).

Interactive Charts

References

• Original Source