Extech EC500 pH measurement equipment 0 - 14 pH EC500 User Manual
Product codes
EC500
EC500-EU V2.2 8/05
13
Troubleshooting
Problem Possible
Cause
Action
Reading is frozen
Unit is in “HOLD” mode
Press MODE/HOLD key to
exit “HOLD” mode
exit “HOLD” mode
“BAT” message
Batteries are low
Replace batteries
Unit will not calibrate in pH
Low pH slope
Replace electrode, see
reorder information
reorder information
Unit will not calibrate in pH
Clogged or contaminated
reference junction
reference junction
Clean junction (see
cleaning instructions)
cleaning instructions)
Unit will not calibrate in pH
Damaged or worn out
sensing membrane
sensing membrane
Replace electrode, see
reorder information
reorder information
Unit will not calibrate in pH
Contaminated pH buffers
Use fresh buffers
Unit will not calibrate in
conductivity mode
conductivity mode
Contaminated conductivity
standards
standards
Use fresh standards
Unit will not calibrate in
conductivity mode
conductivity mode
Dirty probe
Clean conductivity probe
(See cleaning instructions)
(See cleaning instructions)
Unit will not calibrate in
conductivity mode
conductivity mode
Damaged conductivity probe
Replace electrode, see
reorder information
reorder information
Unit will not calibrate in
conductivity mode
conductivity mode
Trapped air bubbles
Tap or stir to release air
bubbles
bubbles
Unit will not turn on
Batteries are low or dead
Replace batteries
Unit will not turn on
Batteries installed with
incorrect polarity
incorrect polarity
Replace batteries,
observe polarity
observe polarity
“RENEW” message
pH sensor needs
recalibration
recalibration
Recalibrate unit
Use fresh buffers
“RENEW” message
pH sensor slope has fallen
below acceptable limits
below acceptable limits
Replace electrode, see
reorder information
reorder information
Unit will not respond to any
key presses
key presses
Internal fault
Perform hard reboot:
Remove batteries, hold
ON/OFF switch down for 5
seconds, replace batteries
Remove batteries, hold
ON/OFF switch down for 5
seconds, replace batteries
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