What is zero drift of PH meter and how to solve it!
What is the zero drift of the PH meter, how to solve! PH meter zero drift problem, first of all, you have to understand the zero drift, affecting the zero drift of the meter more factors, especially direct-coupled amplifiers, it is difficult to completely overcome the serious impact of zero drift. When the power supply voltage varies, the amplifying element characteristics of the working state change, the circuit component parameters with the surrounding temperature changes and the continuation of the working time, in the input is zero when the output has ups and downs, that is, the zero point drift. Again is to find the problem, PH electrode on the problem will be highlighted a lot, such as electrode scaling will cause resistance imbalance between the electrodes and thus cause drift, long-term electromagnetic interference will also lead to problems, electrode polarisation will also affect. A few ways to mitigate the impression of zero drift: 1. the use of regulated power supply, 2. the use of AC amplifier circuits, 3. dynamic input impedance. Industrial pH meter and laboratory PH meter stability and zero drift solutions.
1. Application of negative feedback circuit. In order to reduce the zero drift, improve stability, pH meter amplifier used by the application of negative feedback circuit, the use of DC negative feedback can not only effectively improve the input impedance of the meter, but also improve the stability of the meter, so that the instrument's sensitivity and range is not affected by the changes in the parameters of the electronic components.
