1. Factory Calibration: Functionality Verified Before the Field

The process starts at the factory, where each sensor is individually tested to confirm it’s functioning as expected. This includes a bump test, where the sensor is briefly exposed to a known concentration of target gas to verify responsiveness and basic functionality. This is a pass/fail check to catch any non-responsive or faulty components early on. No accuracy adjustments are made here, but sensors that pass move forward for full calibration. Each unit also receives a unique ID and passes quality checks that ensure only reliable devices continue through the production line.

2. Laboratory Calibration: Zero and Span Calibration in NABL-Certified Labs

Next, the device is sent to a certified lab, ATIRA, for zero and span calibration. Here, the monitor is exposed to pollutant-free air (zero air) followed by span gases with known concentrations. Using NIST-traceable reference gases, the sensor's baseline offset and gain are calculated and corrected. Tests are repeated at different concentration levels under regulated temperature and humidity. This helps simulate real-life environmental conditions and compensates for any cross-sensitivity. The resulting calibration curve is saved in the device’s firmware, ensuring consistent performance across installations.

3. Co-location Calibration: Aligning Performance with Regulatory Standards

After lab calibration, the monitor is installed next to a certified Federal Equivalent Method (FEM) reference analyzer for a 72-hour test run. This co-location phase verifies how the sensor performs under actual ambient conditions, capturing continuous data points at 1 or 5-minute intervals over 72 hours. Linear regression is used to calculate the slope and intercept that best align the monitor’s output with the reference values. This fine-tunes the final calibration and ensures your monitor delivers readings you can rely on in the field. The process follows CPCB and EPA guidelines, providing the confidence to use Oizom data for audits, reporting, and compliance.

4. On-Site Calibration: Maintain Accuracy Over Time

Field conditions can change, and sensor behavior can evolve as well. That’s why Oizom supports optional on-site calibration. Technicians use portable cylinders of zero and span gases and apply them to the sensor using a gas hood. Adjustments are made through the device’s onboard interface or a mobile app. Alternatively, a freshly calibrated Oizom unit can be temporarily placed beside an existing one to act as a reference. These recalibrations are quick and can be performed every three to six months.

Integrated with Automation and Standards Built for Compliance, Designed for Efficiency

All Oizom calibration stages follow international standards. Lab calibration is done in ISO/IEC 17025 (NABL) certified facilities using traceable gases. Co-location meets EPA and CPCB requirements, and our reference labs are equipped to test multiple units at once. For long-term accuracy, devices can be recalibrated remotely via over-the-air updates. Our cloud platform, Envizom, helps manage calibration cycles, monitor system health, and recommend recalibrations using AI-based drift detection. Whether you're working in urban air monitoring, industrial compliance, or sensitive environments, Oizom ensures your data is always precise and audit-ready.