| Ozone identity | O₃; molecular weight: 48.00 g/mol | The sensor responds to ozone molecules in air or dissolved water. | A dedicated ozone sensor is designed to distinguish ozone exposure from general air-quality changes. | Direct measurement of the target gas | Ozone is chemically reactive and can degrade or interfere with some sensing materials. |
| UV absorption method | Usually centered near 254 nm; commonly used for low- to high-range gas monitoring | Ozone absorbs ultraviolet light. The reduction in light intensity is related to concentration through the Beer–Lambert law. | Provides a direct optical measurement without consuming the ozone sample. | Good stability, repeatability, and suitability for continuous monitoring | Requires a clean optical path, stable lamp or light source, and compensation for particles or humidity when applicable. |
| Electrochemical method | Commonly used for personal, indoor, process, and safety monitoring; range depends on cell design | Ozone undergoes an electrochemical reaction at an electrode, producing a current proportional to concentration. | Offers useful sensitivity at relatively low concentrations and can provide compact, low-power detection. | Small size, low energy consumption, and practical field deployment | Electrolyte aging, temperature, humidity, and cross-sensitivity may affect calibration and service life. |
| Metal-oxide semiconductor method | Typically used for trend detection and broad screening rather than high-precision reference measurement | Ozone changes the electrical resistance of a heated metal-oxide sensing layer. | Can indicate rapid changes in ozone levels, especially where cost and ruggedness are priorities. | Low component cost, simple electronics, and long operating potential | Usually more affected by humidity, temperature, and other oxidizing gases than UV-based instruments. |
| Measurement range | Ambient air is commonly measured in parts per billion (ppb); workplace and process systems may require parts per million (ppm). 1 ppm = 1,000 ppb | The sensing element converts ozone concentration into an optical, electrical, or chemical signal. | Selecting a sensor whose full-scale range matches the application helps prevent saturation and improves resolution. | Supports environmental, occupational, water-treatment, and ozone-generation applications | A sensor designed for high concentrations may not resolve low ambient levels effectively, and vice versa. |
| Response time | Often specified as T90, the time required to reach 90% of the final reading; actual values vary from seconds to minutes. | Gas flow rate, sample tubing, filtering, chamber volume, and sensor chemistry influence the time response. | Fast response helps identify leaks, process changes, and short-term exposure events. | Enables real-time alarms and closed-loop process control | Long sampling lines, adsorption, or insufficient airflow can make the displayed value lag behind the actual concentration. |
| Calibration and verification | Zero checks and periodic span verification are recommended; calibration intervals depend on technology and operating conditions. | The sensor output is compared with a known zero condition and a traceable ozone reference or validated comparison instrument. | Regular verification detects drift and supports reliable long-term data. | Improves confidence in alarms, compliance records, and process decisions | Calibration frequency must account for temperature, humidity, contamination, operating hours, and exposure level. |
| Safety relevance | Ozone is a strong oxidant and can irritate the eyes and respiratory system. A commonly cited occupational exposure limit is 0.1 ppm as an 8-hour time-weighted average in U.S. OSHA regulations. | A calibrated sensor continuously tracks ozone and can activate ventilation or alarms when configured thresholds are exceeded. | Continuous measurement can reveal exposure conditions that periodic manual sampling may miss. | Supports worker protection, leak detection, and ventilation control | Exposure limits vary by jurisdiction and application; sensor alarms should not replace required safety procedures. |
| Best-fit applications | Indoor air monitoring, workplace safety, ozone generators, water treatment, food processing, and environmental studies | The sensor is installed at a representative sampling point and connected to a display, data logger, controller, or alarm system. | Application-specific placement and technology selection reduce sampling errors and improve data quality. | Flexible integration with monitoring and automation systems | Poor placement, condensation, blocked inlets, or inadequate airflow can produce misleading readings. |