3M 3MTM Marine Instruments User Manual


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Toxic Gases
The following toxic gases table displays a quick overview of the ranges and the gases needed to perform zero and
span calibrations.
Type of Gas Range Res. Zero cal
gas
Span cal
gas
Carbon Monoxide (CO) 0 -1000 ppm 1 ppm nitrogen/pure air CO
Chlorine (CL
2
) 0.0 - 20 ppm 0.1 ppm nitrogen/pure air CL
2
Ethylene Oxide (EtO) 0.0 - 20 ppm 0.1 ppm nitrogen/pure air EtO
Hydrogen Cyanide (HCN) 0.0 - 50 ppm 0.1 ppm nitrogen/pure air HCN
HydrogenSulde(H
2
S) 0 - 500 ppm 1 ppm nitrogen/pure air H
2
S
Nitrogen Dioxide (NO
2
) 0.0 - 50 ppm 0.1 ppm nitrogen/pure air NO
2
Nitric Oxide (NO) 0.0 - 100 ppm 0.1 ppm nitrogen/pure air NO
Oxygen (O
2
) 0.0 - 30% 0.1% nitrogen
*1.0L/min.owrate
Room air
*span 20.9%
Sulphur Dioxide (SO
2
) 0.0 - 50 ppm 0.1 ppm nitrogen/pure air SO
2
Carbon Dioxide Gas
Similar to toxic gases, the carbon dioxide sensor should be calibrated prior to logging.
Toxic and Carbon Dioxide Zero Calibration
Depending on the gas of interest, the toxic zero calibration is performed with the gas indicated in the table above.
The CO
2
sensorrequiresacalibrationgas,aregulatorwithatleast1.0Liter/minuteowrate,andahose/tubing.
Nitrogen (N
2
) is the recommended gas for a zero calibrating (If you are not applying a gas, start at step 2.)
1. Connect the appropriate gas/pure air, regulator, tubing, and cal. cup to the EVM.
2. Select Calibration from the Start screenandchooseaspecictoxicusing keys. (i.e., CO).
3. Press Cal softkey and then press Zero softkey. Once level is stabilized, press Set softkey. (Allow at least 90
seconds to stabilize.)
4. Press Save or Cancel softkey to store the process. Disconnect components and return to the start screen via
On/Off/Esc key.
Tubing
Regulator
Cal. gas source
Cal. cup/adapter
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