How to use DPD-1 method to calibrate the free chlorine sensor?

This video shows how to calibrate the chlorine sensor with DPD-1 method. The Daruifuno online chlorine controller can be connected with the chlorine sensor and the sensor need to be calibrated before using. So how to calibrate the chlorine sensor? We usually use the DPD-1 method. If you have any questions about the video, feel free to contact us. www.daruifuno.com