71
SECTION 5,
continued
Message*
Probable Cause
Corrective Action
E1
Dilution water is
≥
0.5 NTU.
Start calibration over with
better quality dilution water or
use a membrane filter to filter
the water before use.
E2
Two standards have the same
value or their difference is less
than 60 NTU.
Not all standards were read
during the calibration.
Standard 1 is too low
(<10 NTU).
Recheck preparation of
standards and repeat
calibration.
E3
Low light error.
Re-read measurement.
Check lamp**
Check for obstructed
light path.
Dilution may be necessary.
E4
EEPROM malfunction.
Check sum failed. Press
I/O
.
If E 4 reappears, call Hach
service. If
CAL?
appears,
recalibrate.
E5
A/D overrange.
Check for obstructed
light path.
Call Hach Service.
E6
A/D underrange.
Check for open lid during
reading and re-read. Check for
obstructed light path. If
persists, call Hach Service.
E7
Light Leak.
Close lid before pressing
READ
key.
E8
Bad lamp circuit.
Reinsert lamp leads at
terminal block-make sure the
lead ends are not touching
each other.If this fails, call
Hach Service.
* Error messages 4, 5, and 6 may indicate a failure in the internal electronics.
** Check lamp by inserting a pencil or piece of paper into the cell compartment
and pressing READ. Light should be visible on the inserted object.
