The accuracy of our gas detectors with analog sensors is approximately ±2% (as written on calibration certificates). Aspects affecting the accuracy are sensor drift, temperature, presence of other gases, humidity, etc. As the accuracy of sensors changes in time, the detectors should be recalibrated (interval depends on sensor type).Accuracy of Evikon MCI detectors complies with the European and international standards and is completely sufficient for using the instruments to avoid toxicity or explosion hazards.