Metex 2200P pH Analyzer/Controller - Manual (Page 29)

Model 2200P Page 27
8.0 DIAGNOSTICS
8.1 Description
8.1.1 The 2200P has diagnostic features which alerts the operator to invalid entries and
memory loss. Invalid entries are indicated by the flashing of the appropriate menu
LED. The flashing will commence after RUN is pressed and will continue until the
errors are corrected. Memory loss is indicated by the flashing of TEST and by the
alarm relay if enabled by DIP Switch No. 5 of Bank S1. See Section 4.7.3.
8.2 Invalid Calibration
4.8.3 Invalid calibration will be indicated in the following instances:
• When the difference between the two calibration buffers is less than 10% of the
measuring scale span. To correct, enter the menu and calibrate with more
appropriate buffers. See Section 5.2.
• When the input is out of range. This could occur if you had attempted to calibrate
with a buffer, which was outside the range of the instrument.
8.3 Invalid Output
8.3.1 Invalid output will be indicated if the expanded range is less than 10% of full scale.
To correct, refer to Section 5.4.
8.4 Invalid Alarm Points
8.4.1 Invalid Alarm will be indicated if the Low Alarm is set higher than the High Alarm.
To correct, refer to Section 5.10 and 5.11.
8.5 Invalid Setpoint
8.5.1 The relay off setting must be lower than the relay on if you are controlling rising pH,
and higher than the relay on if you are controlling falling pH. If you have not made
these settings correctly, invalid entry will be indicated by a flashing LED. To
correct, refer to Section 5.5 and 5.8.