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Estoy trabajando en la traducción de un documento técnico y me he encontrado esta expresión "CO test". Desafortunadamente no cuento con más contexto para indicarme el significado de las siglas. Alguna idea relacionada o sugerencia

Chapter 8. Adjusting gas side

On two and three stage burners GL30/40 the gas side is
commissioned prior to the oil side. On regulating burners the
oil side must be commissioned prior to the gas side.
Switch on procedure
• Set operating switch to “gas”
• Open ball valve
• Adjust the gas regulator spring
• Set selector switch in control panel to “Stop”
• Reset installation
• Switch on burner operating switch

Ignition
After the pre-purge time has elapsed, wait for flame formation. If ignition problems occur check the pre-setting of the gas butterfly valve (nominal approx. 5-10 “open” on the scale), as well as the position of the ignition position switch on the servomotor, if necessary increase slightly. Check sensor current using micro ammeter.
Intermediate testing After approx. 20sec. the servomotor runs from ignition position to low fire.

Set the gas pressure into solenoid valve according to table.
Carry out CO test.
G, GL burners:
Make necessary corrections to the pressure settings.
Version ZM:
Disengage servomotor, turn gas regulating cam by hand and re-engage the servomotor. Carry out CO tests at each cam
setting up to high fire.