At present, there are several large-scale analytical instrument companies such as DKK, Foxboro, Yokogawa, Mettler-Trade and ABB in the market, which can produce and provide a variety of pH meter automatic cleaning equipment. Among them, DKK and Yokogawa have a relatively complete range of pH meter automatic cleaning instruments. According to their different working principles, pH meter automatic cleaning instruments can be divided into the following four categories:
(1) Mechanical automatic cleaning. Mainly through mechanical transmission, use a brush to contact the pH meter probe to remove the attachment on the surface of the pH probe.
(2) Ultrasonic automatic cleaning. Rely on a certain frequency of ultrasonic waves to make the attachments on the surface of the pH meter probe vibrate and fall off, so as to achieve the purpose of cleaning.
(3) Automatic spray water cleaning. Under the liquid surface, rely on the impulsive force of water to make the attachment on the pH meter probe fall off.
(4) Chemical cleaning. Under the liquid surface, the mixture of air and chemical cleaning agent is contacted with the pH probe, so that the dirt attached to the surface of the pH probe reacts with the chemical cleaning agent to achieve the purpose of automatic cleaning. This method has higher cleaning efficiency.
