Xylem WQ pH SENSORS - Manual (Page 7)

Global Water
800-876-1172
• globalw.com
- 7 -
V. pH Sensor
a. pH sensor specifications.
Output: 4-19mA
Range: 0-14 pH
Accuracy: 2% of full scale
Operating Voltage: 10-36VDC
Current Draw: 16.6 mA plus sensor output
Warm Up Time: 3 seconds minimum
Operating Temperature: -5° to +55°C
Pressure Rating:
0-100 psi
Size of Probe: 1 1/4" diameter x 10" long
Weight: 1 lb.
b. The sensing element is covered with a protective cap while at the
Global Water facility to prevent the sensor from becoming damaged.
This cap must be removed prior to sensor installation or the readings
will be in error. To remove the cap, remove the protective shield and
remove the rubber cap covering the sensing element. Replace the
protective shield. Note: Save the cap for future use.
c. This sensor has a removable sensing electrode. If the sensor is
reading incorrectly, after following the basic maintenance steps, the
electrode should be removed and the metal contacts cleaned. If this
does not improve the sensor’s results the electrode should be
replaced. To remove the sensing electrode loosen the set screw
holding the sensor shield and remove the shield from the sensor.
Unscrew the sensing electrode from the sensor housing. Clean the
metal contacts of the electrode with a clean cloth. If the electrode is
replaced with a new electrode the sensor must be recalibrated to work
correctly.
d. The pH sensor is a three-wire sensor. Three wire sensors use the red
wire for positive voltage, the white wire for the output signal, and the
black wire for ground. Warning: Always connect the sensor with
the power turned off.