Ventis MX4 - LEL and LEL Correlation Factors for Combustible Gases

Ventis™ MX4 Product Manual
© 2014 Industrial Scientific Corporation
48
The Sensor Cross Sensitivity Table (above) reflects the percentage response provided by the sensor (top row) when
exposed to a known concentration of the target gas (column 1).
The numbers were measured under these environmental conditions: 20 °C (68 °F) , 50% RH and 1 atm.
The specified cross-interference numbers apply to new sensors only, and may vary with time as well as from sensor
to sensor.
“—” means no data available.
This table is given as a reference only and is subject to change.
LEL AND LEL CORRELATION FACTORS FOR COMBUSTIBLE GASES
Sample gas*
LEL
(% vol)
LEL correlation factors
Calibration gas
Butane Hexane Hydrogen Methane Pentane Propane
Acetone 2.5% 1.00 0.70 1.70 1.70 0.90 1.10
Acetylene 2.5% 0.70 0.60 1.30 1.30 0.70 0.80
Benzene 1.2% 1.10 0.80 1.90 1.90 1.00 1.20
Butane 1.9% 1.00 0.58 1.78 1.67 0.83 1.03
Ethane 3.0% 0.80 0.60 1.30 1.30 0.70 0.80
Ethanol 3.3% 0.89 0.52 1.59 1.49 0.74 0.92
Ethylene 2.7% 0.80 0.60 1.40 1.30 0.70 0.90
Hexane 1.1% 1.71 1.00 3.04 2.86 1.42 1.77
Hydrogen 4.0% 0.56 0.33 1.00 0.94 0.47 0.58
Isopropanol 2.0% 1.10 0.90 2.00 1.90 1.00 1.20
Methane 5.0% 0.60 0.35 1.06 1.00 0.50 0.62
Methanol 6.0% 0.60 0.50 1.10 1.10 0.60 0.70
Nonane 0.8% 2.22 1.30 3.95 3.71 1.84 2.29
Pentane 1.4% 1.21 0.71 2.15 2.02 1.00 1.25
Propane 2.1% 0.97 0.57 1.72 1.62 0.80 1.00
Styrene 0.9% 1.30 1.00 2.20 2.20 1.10 1.40
Toluene 1.1% 1.53 0.89 2.71 2.55 1.26 1.57
Xylene 1.1% 1.50 1.10 2.60 2.50 1.30 1.60
JP-4 — — — — — 1.20 —
JP-5 — — — — — 0.90 —
JP-8 — — — — — 1.50 —
NOTE: The table above provides the LEL for select combustible gases*. It also provides correlation factors that help the safety
technician and instrument operator determine the actual percentage LEL when the sample gas differs from the gas that was used to
calibrate the unit.
For example, if the unit reads 10% LEL in a pentane atmosphere, and was calibrated to methane, the actual percentage LEL is
determined as follows:
1. Locate the table cell where the sample gas (pentane) intersects with the calibration gas (methane).
2. Multiply the cell's value (2.02) by the unit's LEL reading (10%) to calculate the actual concentration of 20.2% LEL.
* The combustible gas list is not a comprehensive list of all combustible gases that can be detected by the Ventis MX4. For
additional information about combustible gas detection and the Ventis MX4, contact the ISC Technical Service department.