I need to find the way to measure ozone
Most people buy an ozone sensor. Many are available.
Standalone monitors cost about minimum $200. Since you're at the arduino sensor forum, I take it that you're looking to use an arduino and an ebay sensor.
They are usually stand alone or a module on a circuit board. THis and other similar MQ gas sensors rely on differentials in the voltages between a reference and sensor.
Ozone sensors are generally high concentration or low concentration.
The key for these sensors is to write the code to translate the readings into PPB (low) or PPM (High) readings.
I'm beginning my MQ131 project and will probably start a project page once I get my materials together which includes the sensors, arduino uno, and other components (load resistor, voltage regulator, display, etc).
My application is for high concentration measurement. Just be careful with this gas as it is an oxidizer and exposure to skin, nasal passages, lungs, needs to be avoided.