One multigas analysis instrument to be used for precise testing of diesel engines in underground mining applications: regulation compliance (in some countries maximum emissions from engines are regulated to be able to set ventilation rates), health risk (a build up of these gases can be dangerous to individuals; CO, NO and NO2 have regulated exposure concentrations), operating costs (increases in CO/NOx output can indicate a problem with the engine or the scrubbers resulting in reduced fuel efficiency), reduce downtime (using these values as pre-indicator for engine breakdowns can enable preventive maintenance instead of reactive measures and loss of production).