Hanna Instruments HI 221 - Manual (Page 17)

17 6
_ The selected resolution of the instrument during calibration (HI 223 only).
_ The calibration Alarm Time-Out status:
if disabled
or the number of days until the calibration alarm will be displayed
or if expired (7 days ago)
Press the GLP key at any time and the instrument will return to measuring mode.
If calibration has not been performed, the instrument displays “no CAL”
blinking.
RCL
CAL
pH