A new ozone sensor for an ozone generator

A stable ozone sensor for quantitative analysis, targeted to be a monitor for an ozone generator, is proposed. The operation principle of the sensor is similar to that of a catalytic combustion sensor. The proposed sensor uses two thermal devices of physically and chemically identical characteristics. No catalytic materials such as noble metals are utilized in the present sensor. Unlike a catalytic combustion sensor, which measures catalytic oxidation heat, the proposed ozone sensor measures thermal decomposition heat. The first device, a detecting device, is operated well above the thermal decomposition temperature of ozone, whereas the second device, a reference device is operated near room temperature to avoid thermal decomposition. The detecting device detects the ozone by temperature rise of ozone decomposition origin, and the reference device compensates ambient temperature drift. The reference signal is amplified with appropriate gain and is subtracted from the signal of the detecting device to form temperature-compensated output signal. oposed sensor exhibited excellent sensing characteristics with good reproducibility and long-term stability. Effect of ambient temperature drift was suppressed almost completely. Other sensing characteristics, such as effect of source gas composition, humidity, and pressure is also discussed.