The reading of the online pH meter fluctuates severely
Thread Content
One Mettler online pH meter in our facility suddenly started showing severe fluctuations in its readings; both the on-site display and the DCS system showed such fluctuations. I replaced the cable, the cylinder, and the electrodes, and after testing with verification solutions numbered 4 and 7, the readings remained stable. However, once the electrodes were reinserted into the cylinder and the device was put back into use, fluctuations persisted again. The process team stated that there was nothing wrong with their materials. I would appreciate it if someone could help analyze the possible causes. Thank you
Pressure fluctuations? Poor voltage resistance? I once encountered a device whose pH value was problematic; changing the electrode resolved it.
First, rule out wave phenomena in the medium; second, check the instrument for problems