Use this calibration gas:

20ppm Hydrogen Sulfide
60ppm Carbon Monoxide
58% LEL Pentane (1.45% Volume Methane as a Simulant)
15.0% Oxygen
Nitrogen Balance

Want to calibrate the MSA Altair 4 or MSA Altair 4X? Here's how:
1. Turn the MSA Altair 4 and MSA Altair 4X on in normal reading mode. Do this by pressing and holding the center button.
2. Once the MSA Altair 4 and MSA Altair 4X is in normal reading mode, you need to send it into calibration mode. Do this by pressing and holding right beeps at you and the screen asks you to zero the monitor (sensor refresh on the MSA Altair 4X).
3. Now that the screen is asking for confirmation, press the center button once to confirm. This will send the monitor into zeroing mode. Now is a good time to set the monitor down, and grab your calibration gas, regulator, and calibration adapter.
4. Open the valve on your regulator. This is a very important step so you do not ruin your calibration gas cylinder. Now screw it in to your calibration gas cylinder. Close the regulator once you hear gas spewing out of it. This is the signal to know your regulator is good to close. Continue screwing in the regulator until it stops. Do not overturn it.
5. Attach the tubing to the hose barb on your regulator. Make sure the tubing is also connected to your calibration adapter.
6. Wait for the screen to come up asking for you to apply calibration gas. Once this screen comes up, press the center button again to confirm. Screw the calibration adapter in to your gas detector. Once it is screwed on, turn on your gas.
7. Make sure your calibration gas values on the screen match what is on your calibration gas cylinder!
8. Once the calibration procedure is completed, turn your gas off and remove the calibration adapter from the MSA Altair 4 or MSA Altair 4X. The screen will go back to normal reading mode within a few seconds.
9. Congratulations! You have officially calibrated your MSA Altair 4 or MSA Altair 4X gas monitor. Make sure to record these readings in your calibration log!