mg/m³ to ppm Conversion Calculator by Tons of Concrete

Conversion Formula:

\[ \text{ppm} = \frac{\text{mg/m}³ \times 24.45}{\text{MW}} \]

Concentration (ppm):

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1. What is mg/m³ to ppm Conversion?

Definition: This calculator converts concentration from milligrams per cubic meter (mg/m³) to parts per million (ppm) for gases.

Purpose: It's essential for air quality measurements, industrial hygiene, and chemical safety where different units are used.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{ppm} = \frac{\text{mg/m}³ \times 24.45}{\text{MW}} \]

Where:

ppm — Parts per million (volume/volume)
mg/m³ — Mass concentration (milligrams per cubic meter)
24.45 — Molar volume of ideal gas at 25°C (liters per mole)
MW — Molecular weight of the substance (grams per mole)

Explanation: The formula converts mass concentration to volume concentration using the molar volume at standard conditions.

3. Importance of Unit Conversion

Details: Different industries and standards use different units. Conversion ensures proper interpretation of concentration values.

4. Using the Calculator

Tips: Enter the concentration in mg/m³ and the molecular weight of the substance. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is 24.45 used in the formula?
A: It's the molar volume (in liters) of an ideal gas at 25°C (298.15K) and 1 atmosphere pressure.

Q2: Does temperature affect the conversion?
A: Yes, the 24.45 factor is for 25°C. For other temperatures, use: 24.45 × (T/298.15) where T is in Kelvin.

Q3: Where can I find molecular weights?
A: Chemical reference tables provide MW values (e.g., CO₂ = 44.01 g/mol, O₂ = 32.00 g/mol).

Q4: Can I use this for liquids or solids?
A: No, this conversion is specifically for gases at standard conditions.

Q5: What's the difference between ppmv and ppm?
A: For gases, ppm typically means ppm by volume (ppmv). For liquids/solids, ppm usually means by mass.