How often should the pH reference be replaced?
When the pH becomes unstable, or drifts significantly after calibrating the meter, the pH reference is probably depleted and the meter needs to be sent in for service/repair. My conductivity reading says ‘Lo’ or is very erratic. There are a few things that can cause this symptom. The most common is that the meter is ‘sucking air’, or has air bubbles in the measurement cell. The best way to dislodge air bubbles from the meter is to give a hard, rapid pull on the syringe and then flush it back and forth rapidly a couple of times. If the symptom still persists, then air may be being draw into the meter along with the sample. This could be from a cracked luer or a leaking check valve on the Tri-Station. If it has been determined that there is no air being drawn into the meter and the symptom still persists, then it is probable that the measurement cell is damaged. The meter needs to be sent in for service/repair. My meter didn’t show ‘C1-C2’ (‘CAL’) when calibrated. The ‘C1-C2’ (‘CAL’) tha
