Xylem WQ730 TURBIDITY SENSOR - Manual (Page 9)

Global Water
800-876-1172
• globalw.com
- 9 -
Checking Calibration
Step 1) Connect the sensor to the power supply and current meter in
the following way. Attach the black wire to the ground terminal
of the power supply. Attach the white wire to the positive
current input of the meter. Connect the ground terminal of the
power supply to the ground input of the current meter. Check
that the power supply is set between 10 and 30 volts DC.
Attach the red wire to the positive terminal of the power supply.
Warning: Always hook up the red wire last or the sensor may
be damaged.
Step 2) Place the turbidity sensor in the distilled water beaker, rinse
and dry. Clean the lenses with alcohol.
Step 3) Place the sensor in the clamp above the 0.0 NTU standard.
Turn on the power supply and the current meter. Let the
sensor stabilize for several seconds before taking any
measurements. If necessary, use a lint free cotton swab bent
at 90º to remove any air bubbles from underneath the detector
window. Air bubbles will cause large errors in the current
output, especially at low turbidity values.
Step 3) Record the output current of the sensor, Zero
(1000)
= _______.
Disconnect the white wire and connect the green wire to the
positive input of the current meter. Let the sensor stabilize.
Record the output current of the sensor, Zero
(50)
= _______.
Step 4) Remove the sensor and rinse in distilled water. Dry the sensor
and clean the lenses with alcohol.
Step 5) Place the sensor in the clamp above the 50 NTU solution. If
necessary, use a lint free cotton swab bent at 90º to remove
any air bubbles from underneath the detector window.
Step 6) Record the output current of the sensor, 50NTU = _______.