PRODUCT INSTRUCTION SHEET
SECTION 10.0
SENSOR MAINTENANCE/RECONDITIONING
10.1GENERAL MAINTENANCE. Service the sensor regularly (weekly is suggested)
10.2MEMBRANE CAP REPLACEMENT. If membrane replace- ment is required, a new cap with preinstalled membrane must be used. Order
a) turn sensor upside down with cap facing upward
b) rotate cap
c) fill sensor body with electrolyte using needle and bottle of refill solution (see FIG. 11)
d) install a new membrane cap by threading cap onto sensor rotating cap clockwise (opposite of FIG 10)
10.3MEMBRANE CAP/SENSOR CLEANING. Rinse cap with
water only. If cap does not clean, replace with new one.
SECTION 11.0
SENSOR TROUBLESHOOTING
11.1CALIBRATION PROBLEMS
a)Sensor output HIGHER than DPD test
1)Run in time too short
2)Membrane cap damaged
3)Interference from water contaminants (see Specifications, "Cross Sensitivity")
4)Cable short circuit or damage
5)pH value less than pH 5.5
b)Sensor output LOWER than DPD test
1)Run in time too short
2)Deposits on Membrane cap
3)Flow rate too low
4)Air bubbles on membrane
5)Surfactants in water
6)pH value more than pH 8.0
7)No electrolyte in membrane cap
c)Sensor ouput is 4mA (zero ppm)
1)Run in time too short
2)Only bound chlorine present
3)Chlorine content below detection limit
4)Sensor not wired correctly (See SECTION 6.0 of this manual)
5)Defective sensor
d)Sensor output UNSTABLE
1)Air bubbles on membrane
2)Membrane damage
3)
FIG. 10 | FIG. 11 |
INJECT UNTIL SOLUTION
LEAKS OUT OF FILL HOLE
TROUBLESHOOTING CHART
Symptom | Possible Cause | Solution/Remedy |
The sensor | 1) Run in time too short | 1) See Sec 5.0 |
cannot be | 2) Membrane cap damaged | 2) Replace cap - See Sec 8.0 |
calibrated- | 3) Interference from contaminants | 3) See SPECIFICATIONS |
ouput is | 4) DPD chemicals bad | 4) Use new DPD kit |
HIGHER than | 5) pH value < pH 5.5 | 5) Increase pH |
DPD Test |
| See SPECIFICATIONS |
| 6)Temperatue increased since cal | 6) Match calibration temp. |
The sensor | 1) Run in time too short | 1) See Sec 7.0 |
cannot be | 2) Deposits on membrane cap | 2) Remove deposits or replace |
calibrated- |
| cap if cleaning ineffective. |
output is | 3) Flow rate too low | 3) increase flow - See |
LOWER than |
| SPECIFICATIONS |
DPD Test | 4) Air bubbles on membrane | 4) Remove and |
|
| sor to remove bubbles. |
| 5) Surfactants in water | 5) Remove surfactants and |
|
| replace cap |
| 6) pH > pH 8.0 | 6) Lower pH |
|
| See SPECIFICATIONS |
| 7) No electrolyte in cap | 7) Add new electrolyte, run in |
|
| sensor and |
| 8) Temperature decreased since cal | 8) Increase temp to match cal |
| 9) Organic chlorination agents | 9) Use chlorinating agents |
| present in water | per DIN 19643 |
Sensor output | 1) Only bound chlorine present | 1) Check for Chloramine with |
is 4mA (0 ppm) | NO FREE CHLORINE | appropriate DPD test. |
|
| Replace water/ Rechlorinate. |
| 2) Run in time too short | 2) See Sec 7.0 |
| 3) Chlorine content below limit | 3) Add chlorine and repeat |
|
| calibration |
| 4) No electrolyte in cap | 4) Refill electrolyte |
| 5) Sensor electrical connection | 5) See SECTION 6.0 |
| wrong |
|
Unstable output | 1) Air bubbles on sensor membrane | 1) Tap to remove bubbles |
from sensor | 2) Membrane damaged | 2) Replace membrane, run in |
|
| sensor and recalibrate. |
| 3) | 3) check PLC or I/O device |
|
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| M4679/0708 page 5 of 6 |
Parts covered by this product instruction sheet include: