When I on the APERA for Ph testing it shows -2.0. How to remove it copy attached for perusal.
It has been my experience with this unit that the -2.0 comes onto the screen when there is an issue with the electrode or the connection between the electrode and the circuit board. You can try and unplug the electrode from the meter, check that the electrode socket and circuit board pins appear clean and then refit the electrode. In most cases I have seen (unless there is a more serious electrode issue), it will rectify itself and when you put it into a solution, it will read correctly.
Kind reference is invited to the above information regarding unplug the electrode from the meter. Even after doing it the issue remains the same. Kindly advise if there is any Technical service center in India where this issue can be sorted out..