How does Kaiterra convert TVOC readings from ppb to µg/m³?

Understanding how Total Volatile Organic Compounds (TVOC) are measured and converted is essential for accurate indoor air quality monitoring. Below are the most common questions regarding how Kaiterra devices handle the conversion between parts per billion (ppb) and micrograms per cubic meter (µg/m³).

How do Kaiterra sensors measure TVOC?

Kaiterra uses Metal Oxide (MOx) sensors. These sensors detect VOCs by measuring a change in electrical resistance on the sensing surface when gas molecules are present. Because different gases cause different levels of resistance, the sensor must be calibrated against a specific reference gas mixture to provide a readable value.

What is the default conversion factor used by Kaiterra?

To convert a TVOC reading from ppb to µg/m³, Kaiterra uses a default conversion factor of 4.57.

The Formula: TVOC (µg/m³) = TVOC (ppb) x 4.57

This factor is based on an average molar mass of 110 g/mol. This specific molar mass derived from the work of Mølhave et al. aligns with the gas mixtures most commonly found in indoor environments and is widely accepted as the current Indoor Air Quality (IAQ) industry standard for TVOC reporting.

Can I use a different conversion factor?

Yes. While 4.57 is the standard, Kaiterra recognizes that specific environments (such as industrial sites or laboratories) may have a unique mix of gases that differ from the standard indoor profile.

Kaiterra enables users to enter a custom conversion factor within the device settings. This allows you to tailor the readings if you have specific knowledge of the chemical constituents in your environment.